GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO The International Treaty ON PLANT GENETIC RESOURCES FOR FOOD AND AGRICULTURE DISCLAIMER This document aims to provide a framework for the efficient and effective conservation of potato genetic resources. The overall objective is to outline shared responsibilities and needs for the long-term conservation of these genetic resources and to facilitate their use for food security and sustainable agriculture. The Crop Trust considers this document to be an important framework for guiding the allocation of its resources. However, the Crop Trust does not take responsibility for the relevance, accuracy or completeness of the information in this document and does not commit to funding any of the priorities identified. This strategy document (12 November 2022) is expected to continue to evolve and be updated as and when circumstances change, or new information becomes available. ACKNOWLEDGMENTS This 2022 edition of the ‘Global Strategy for the Conservation of Potato’ builds on the first strategy coordinated by van Soest (2006). It focuses on ex situ conservation of species of Solanum section Petota and includes priority actions to improve ex situ and in situ conservation and use of potato genetic resources. In addition, an overview of recent taxonomic studies, progress in breeding and sequencing and in situ conservation projects is provided, and new tools for ex situ conservation management, germplasm characterization & evaluation, including data management, are presented. The global strategy is the product of a collaborative effort, which could not have been accomplished without both individual and group contributions. We would like to thank all who participated actively in discussions and in reviewing the final draft, which was circulated to all partners and potato collection curators and appreciate especially the contributions of Glenn Bryan (James Hutton Institute, Invergowrie, UK), Alfonso Del Rio (University of Wisconsin, Madison, USA), Gustavo Heiden (Embrapa Clima Temperado, Pelotas, Brazil), Roel Hoekstra (Center for Genetic Resources, Wageningen, the Netherlands), Colin Khoury (San Diego Botanic Garden, San Diego, USA), Juan Carlos Alarcon Maldonado (Crop Trust, Bonn, Germany), Norma Manrique (International Potato Center, Lima, Peru), Caroline Marques Castro (Embrapa Clima Temperado, Pelotas, Brazil), Iris Edith Peralta (Universidad Nacional de Cuyo, - CONICET, Mendoza, Argentina), Mathias Obreza (Crop Trust, Bonn, Germany), Rainer Vollmer (International Potato Center, Lima, Peru), Stephan Weise (Leibniz-IPK, Gatersleben, Germany), Richard Visser (Wageningen University, Wageningen, the Netherlands), Shin-ichi Yamamoto (Research Center of Genetic Resources, National Agriculture and Food Research Organization, Tsukuba, Japan). Further, we want to acknowledge Klaus J. Dehmer (Leibniz-IPK, Groß Lüsewitz, Germany) for providing beautiful photos, helpful comments and supporting the ‘Potato Strategy Meeting’ held virtually in November 2021. The development of this Global Crop Conservation Strategy was funded by the Government of Germany (BMEL) as part of the three-year project led by the Crop Trust: “Breathing new life into the Global Crop Conservation Strategies: Providing an Evidence Base for the Global System of Ex situ Conservation of Crop Diversity.” The Crop Trust also cooperated with the Secretariat of The International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGRFA) in the development of this document. Annex 2 of this document provides a summary of a recent report: “The plants that feed the world: baseline information to underpin strategies for their conservation and use”. That study was produced as a collaboration led by the Secretariat of the Plant Treaty, and involving the Alliance of Bioversity, the International Center for Tropical Agriculture (CIAT and the Crop Trust, funded by the Norwegian Agency for Development Cooperation (NORAD, Government of Norway). AUTHORS Manuela Nagel, Leibniz Institute of Plant Genetics and Crop Plant Research, Germany Ehsan Dulloo, International Consultant Prishnee Bissessur, International Consultant Tatjana Gavrilenko, N.I. Vavilov All-Russian Institute of Plant Genetic Resources, Russia John Bamberg, USDA/ARS – U. S. Potato Genebank, USA David Ellis, International Potato Center (CIP), Peru Peter Giovannini, Global Crop Diversity Trust SUGGESTED CITATION Nagel, M., Dulloo, M. E., Bissessur, P, Gavrilenko, T., Bamberg, J., Ellis, D. & P. Giovannini (2022). Global Strategy for the Conservation of Potato. Global Crop Diversity Trust. Bonn, Germany. https://doi.org/10.5447/ipk/2022/29 COVER Created © Uli Westphal 2022. Uli Westphal is a visual artist who documents our declining crop diversity and the things that replace it. The ‘Cultivar Series’ portrays the existing diversity within individual crop species, one species at a time. www.uliwestphal.com/the-cultivar-series This work is licensed under a Creative Commons Attribution-NonCommercial- ShareAlike 4.0 International (CC BY-NC-SA 4.0) License. To view a copy of this license, visit https://creativecommons.org/licenses/by-nc-sa/4.0/ CONTENTS EXECUTIVE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1 INTRODUCTION AND STRATEGY BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2 ORIGIN, DOMESTICATION AND CENTERS OF DIVERSITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2 .1 Definition of wild species, landraces, improved varieties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2 .2 Domestication process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2 .3 Domestication traits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2 .4 Geographic distribution and centers of diversity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2 .5 Geographical spread and the rise of modern varieties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3 TAXONOMY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3 .1 Historic background of potato taxonomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3 .2 Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 4 POTATO PRODUCTION AND DIVERSITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 4 .1 Economic importance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 4 .2 Potato development, descriptors and potato diversity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 5 IN SITU CONSERVATION OF NATIVE POTATO VARIETIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 5 .1 Threats to native potato diversity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 5 .2 In situ conservation projects in Latin America . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 5 .3 Complementarity with ex situ conservation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 5 .4 Current challenges of in situ conservation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 6 POTATO EX SITU COLLECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 6 .1 Ex situ conservation and priorities in genebanks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 6 .2 Historic potato collection missions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 6 .3 Information on the potato germplasm collections and the survey . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 6 .4 Ex situ collections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 6 .5 Biological status of potato accessions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 6 .6 Challenges of differences in potato classification systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 7 POTATO GERMPLASM MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 7 .1 Ex situ maintenance of potato . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 7 .2 Field maintenance and short-term warehouse storage of seed potato . . . . . . . . . . . . . . . . . . . . . . . . . 64 7 .3 Medium-term storage through in vitro slow-growth maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 7 .4 Long-term storage via cryopreservation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 7 .5 Storage of orthodox potato seed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 7 .6 Challenges of potato germplasm maintenance and steps to improve . . . . . . . . . . . . . . . . . . . . . . . . . 69 8 MANAGEMENT OF THE COLLECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 8 .1 Establishment of procedures and protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 8 .2 Regeneration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 8 .3 Duplication status and security backups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 8 .4 Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 8 .5 Challenges and predictions for collection management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 3 9 DATA MANAGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 9 .1 Management and types of genebank data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 9 .2 Accessibility of potato germplasm data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 9 .3 Required improvements for data management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 10 COLLECTION GAPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 10 .1 Gap analysis – a tool to aid conservation of plant genetic resources . . . . . . . . . . . . . . . . . . . . . . . . . 86 10 .2 Origin of the potato collections assessed by the survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 10 .3 Gaps considered by the survey participants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 10 .4 Identification of gaps in the representation of potato wild species . . . . . . . . . . . . . . . . . . . . . . . . . . 89 10 .5 Gap analysis for potato landraces of the ‘Andigenum group’ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 10 .6 Challenges and steps towards gap filling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 11 POTATO BREEDING AND USAGE OF THE COLLECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 11 .1 Historical aspects of potato breeding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 11 .2 Genetic hurdles in potato breeding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 11 .3 Potato gene pools and use of wild species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 11 .4 Breeding strategies and approaches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 11 .5 Sequencing information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 11 .6 Policies on access to collections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 11 .7 Type of collection and uniqueness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 11 .8 Characterization and evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 11 .9 Challenges and Priorities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 12 RECOMMENDED PRIORITIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 Action Point 1: Comprehensive genotyping of ex situ and in situ collections . . . . . . . . . . . . . . . . . . . . . . . . 114 Action Point 2: Harmonization of potato taxonomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 Action Point 3: Documentation and monitoring of in situ populations and traditional landraces maintained on farm in American countries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 Action Point 4: Capacity building for in situ conservation and improved strategic concepts for on farm conservation . 115 Action Point 5: Collecting missions and linkage between in situ/on farm and ex situ conservation . . . . . . . . . . . 115 Action Point 6: Capacity building to maintain high quality ex situ collections, in particular in Latin American countries 115 Action Point 7: Cryopreservation is needed to ensure long-term survival of potato genetic resources . . . . . . . . . . 116 Action Point 8: Further digitalization, better linkage and visibility of publicly available data for ex situ and in situ conser- vation management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 Action Point 9: Accessibility of collections for breeding and use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 Action Point 10: Networking and training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 ANNEXES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Annex 1 . A survey to build a global conservation strategy for potato . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Annex 2 . Selected metrics for potato and cassava (as comparison) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 Annex 3 . Number and category of potato accessions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 Annex 4 . Potato germplasm collections classified as wild species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 Annex 5 . Collection of landraces maintained in national and international genebank . . . . . . . . . . . . . . . . . . 156 Annex 6 . Consultation agenda . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 4 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO EXECUTIVE SUMMARY Background . Cultivated potato, Solanum tuberosum and meeting participants, resulted in ten action points ssp. tuberosum, is the third most consumed crop being identified as strategic priorities. globally and important not only for food but also for for the animal feed, pharmaceutical, textile and paper Domestication and taxonomy . Wild potatoes are industries. To gain an overview on the current state of native to the Americas, with highest number of the conservation and use of potato genetic resources, species found in Peru, Mexico, Argentina, Bolivia, the Global Crop Diversity Trust (Crop Trust), commis- Ecuador and Colombia (Spooner et al., 2014). Cul- sioned an update of the ‘Global conservation strategy tivated potatoes were domesticated in the Andes for potato genetic resources’. This updated strategy about 8,000 to 10,000 years ago in a series of several aims to support the efficiency and effectiveness of domestication events (Ovchinnikova et al., 2011), and potato diversity conservation at national, regional from there were spread around the world, most likely and international levels, and to identify priorities for from 1562 onwards (Ugent, 1968; Hawkes and Fran- strengthening the conservation and use of potato cisco-Ortega, 1993). Nowadays, 370 million tonnes genetic resources. of potatoes are produced on 16.5 million ha globally (FAOSTAT, 2021b). Wild and cultivated potato belong To provide an overview of the current status of the to the genus Solanum L., subgenus Potatoe (G. Don) potato collections worldwide, a survey was sent out in D’Arcy, section Petota Dumort. This is characterized by 2020 and 2021, and responses were analyzed from 32 introgressions, interspecific hybridization, auto- and genebanks located in: allopolyploidy and numerous evolutionary events, • Asia: India (IND665), China (CHN116, CHN122), leading to many taxa. Hawkes (1990) divided this Japan (JPN183) section into 21 taxonomic series, including 19 series • Europe: Belgium (BEL023), Bulgaria (BGR001), for tuber-bearing species (subsection Potatoe G. Don) Czech Republic (CZE027), Estonia (EST019), France and two series of non-tuberous species (subsection (FRA010), Germany (DEU159), Ireland (IRL012, Estolonifera Hawkes). Within the subsection Potatoe IRL036), Netherlands (NLD037), Latvia (LVA006), G. Don, Hawkes (1990) described 7 cultivated potato Romania (ROM007), Russia (RUS001), Slovenia species and 228 wild potato species. The more recent (SVN019), Spain (ESP016), Sweden (SWE054), taxonomic revision by Spooner et al. (2014) combines United Kingdom (GBR165, GBR251) molecular studies and morphological data and groups • International Center: CIP (PER001) wild potatoes into 107 species and the cultivated • Latin America: Argentina (ARG1347), Brazil potatoes into four species: (1) Solanum tuberosum, (BRA020), Chile (CHL071), Colombia (COL017), with two cultivar groups; the ‘Andigenum group’ with Cuba (CUB005), Ecuador (ECU023), Guatemala diploids, triploids and tetraploid species, and the ‘Chi- (GTM001), Peru (PER860), lotanum group’ (tetraploid); (2) Solanum ajanhuiri Juz. • North America: Canada (CAN064), USA (USA004). & Bukasov (diploid); (3) Solanum juzepczukii Bukasov (triploid); and (4) Solanum curtilobum Juz. & Bukasov Data from WIEWS (2021), Genesys, EURISCO and (pentaploid). Although most potato collections follow current peer-reviewed literature was integrated and the taxonomic system defined by Hawkes (1990), some discussed at a ‘Potato Strategy Meeting’ held vir- genebanks have already switched to Spooner et al. tually between 10–12 November 2021. As a result, (2014) which hampers gap analysis and statistics. The the strategy provides an up-to-date overview on the use of different taxonomic treatments may limit stake- origin, domestication, taxonomy, gap analysis and holders’ ability to find and use material. breeding of potato and its economic importance. It summarizes recent in situ conservation projects, In situ conservation . More than 3,000 different tra- including threats and challenges for the preservation ditional landraces and 107 wild species according to of potato landraces and wild species in the region of the classification of Spooner et al. (2014) are native to origin. Based on the survey, an overview is provided the Americas and urgently require protection. Tradi- of ex situ collections, including storage, maintenance, tional landraces are threatened due to the migration regeneration, distribution, data management prac- of farmers, replacement by other crops and improved tices and information about the use of the material varieties, pests and diseases, and low accessibility of for research and breeding. A comprehensive analysis virus-free material. Among wild potatoes, 26 spe- of the survey results, complemented by the major cies are on the IUCN Red List and are threatened by constraints and priorities identified by respondents urbanization, fire, and disturbance by humans and GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 5 livestock (Cadima et al., 2014). Therefore, projects either at 4°C or at -10 to -20°C. Only seven genebanks in Peru, Bolivia, Ecuador, Argentina, Chile and Brazil have backed up their collection in the own country or have identified conservation sites and strategies to at the Svalbard Global Seed Vault. Due to the urgent maintain potato genetic diversity in combination with need to regenerate 30% of the Latin American wild knowledge, culture and traditions. One prominent species collections and 8% of the total collections, concept is the support of “guardians” who cultivate improvements in regeneration, duplication and con- and conserve native potato varieties and pass on tra- servation approaches are needed. ditional knowledge to the next generations (Naranjo, 2019). However, the role of in situ conservation is The collection of landraces has increased by +7% still underestimated in the countries of origin and compared to the last survey (van Soest, 2006), and inventories, biodiversity monitoring, staff training and includes 18,491 accessions, most of which belong to protected sides are required to conserve potato diver- the Solanum tuberosum ‘Andigenum group’. However, sity as well as biodiversity generally in their natural the number of landraces has decreased in the Nether- habitats. lands, UK, Argentina and Russia, which may indicate some challenges in their maintenance. In European, Ex situ collections . Worldwide, a collection of 82,293 North American, Asian countries and at PER001, most, potato accessions is maintained in 89 institutions but not all, genebanks apply standardized protocols and four international/regional centers located in and use low-temperature tuber and in vitro storage 59 countries. Only five institutions (DEU159, FRA010, facilities. PER001, DEU159 and JPN183 have major IND665, RUS001, USA004), together with the Inter- parts of their material cryopreserved. In Latin America, national Potato Center (PER001) conserve more than most landraces are maintained in fields and/or in vitro 50% of all potato accessions globally. Over the last 15 at 17 to 24°C. About 1,600 accessions, 53% of the years, potato genebanks have increased the number Latin American landrace collection, require urgent of accessions by an average of + 42%, and now main- regeneration and are affected by plant health issues, tain collections composed of 20% wild species, 23% staff shortage and outdated infrastructure. Here, landraces, 25% improved varieties and 27% breeding substantial support, in particular with staff training, lines. However, compared to the last survey (van Soest, cold storage facilities, in vitro back up systems and 2006), the number of breeding lines has increased by cryopreservation is needed to safely conserve the tra- +107%, while the number of accessions of wild species ditional landraces in the country of origin. has decreased by 5.8%. Collections of improved varieties and breeding lines The largest wild potato species (applying Spooner et have increased by 100% and 107% compared to the al. (2014)) collections are maintained by CIP (PER001; last survey and comprise 20,735 and 22,173 accessions, 95 species), USA (USA004; 79 species), Russia (RUS001; respectively. Most of these are working or breeding 70 species), Germany (DEU159; 66 species) and the collections situated in Europe and Asia and focus on Netherlands (NLD037; 60 species). The species with the breeding and maintenance of national varieties. Most largest number of accessions are Solanum brevicaule institutions keep the material in field collections, in in Bitter (1,896 accessions), Solanum acaule Bitter (1,491 vitro facilities at 17 to 24°C and/or at 2 to 10°C. About accessions) and Solanum stoloniferum Schltdl. (1,255 6% of the improved varieties and 3% of the breeding accessions). Most accessions are preserved as orthodox lines require urgent regeneration. In Latin America, seeds, but only a few of the genebanks are able to however, the situation is comparable to that of land- apply the ABS (active-base-security) sample system rec- races, and institutions require funding for training ommended by the Genebank Standards (FAO, 2014). staff, as well as cold and in vitro storage facilities. In Most seeds are sealed in aluminum bags and stored addition, support from the Global Plant Cryopreserva- Genebanks conserving 50% of potato germplasm . Total number of accessions and percentage of wild species (W), landraces (L), improved varieties (V) and breeding lines (B) is provided for each collection. Institute Code Country Institute name and place W-L-V-B Number of accessions FRA010 France INRAE, the Institute for Genetics, Environment and Plant Protection, Ploudaniel 5-2-10-83% 12,120 RUS001 Russia VIR, N.I. Vavilov All-Russian Institute of Plant Genetic Resources, St. Petersburg 24-40-29-7% 8,150 PER001 Peru CIP, International Potato Center, Lima 35-60-5-0% 7,467 DEU159 Germany IPK, Leibniz Insitute of Plant Genetics and Crop Plant Research, Groß Lüsewitz 22-37-31-10% 6,247 USA004 USA USDA, US Potato Genebank, Wisconsin 69-20-5-6% 5,900 IND665 India ICAR, Central Potato Research Institute, Shimla 8-3-69-2% 4,257 6 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO tion Initiative is urgently needed for all clonally prop- molecular and hybrid breeding in combination with agated potato accessions to enable secure long-term broadening genetic diversity. However, the complex conservation. genetic nature of the heterozygous tetraploid potato (AAAA, 2n = 4x = 48, estimated haploid genome Data management . Data related to registration, size 844 Mb), the number of quality traits required, storage and regeneration methodologies, phytosani- and the numerous pests and diseases which affect tary certificates, monitoring, characterization, evalu- the crops have always been a challenge for potato ation and distribution generated in the management breeding programs. So far, 27 respondents of the of potato collections need to be securely stored. Most survey have partly screened their collections for late genebanks use electronic information systems, such blight, the main biotic threat of potato production. as GRIN-Global (e.g. BOL317, EST019, PER001, PRT102, About 50% of the collections are (partially) evalu- SWE054, USA004), SIRGE (PER860), ALELO (BRA020), ated for nematodes and the potato viruses Y (PVY) Germinate (GBR251), GBIS (DEU159), GENIS (NLD037) and X (PVX). Screening for other insects, pests and and/or Excel but paper records are still common. diseases (i.e. common scab, potato wart, Fusarium dry Overall, 65% of passport data, 35% of characteriza- rot, Colorado potato beetle) and abiotic stresses (i.e. tion data and 33% of evaluation data are available in drought, heat, cold) has been conducted only by a few electronic form. Twenty out of 32 collections provide genebanks. More characterization efforts are required this information at least partly via the internet or via in combination with the sequencing of all collections international aggregator systems such as EURISCO or and accessibility of data on adequate platforms. In Genesys. To improve the usability of the collections, general, sequencing is of fundamental importance accessions should be linked to a Digital Object Iden- for taxonomy, conservation, genebank management tifiers (DOI) issued by FAO and trained staff should and breeding and must be an overall goal for future produce Findable-Accessible-Interoperable-Reusable genebank processes. (FAIR) phenotypic data and store all information on genebank information systems. Overall, based on the survey, literature review and discussions with stakeholders, a number of key chal- Accessibility of the collections for breeding and lenges for potato conservation and use were identi- conservation . Globally, the access to potato genetic fied and recommendations were made to improve the resources is limited and 37% of wild species, 43% status and use of potato collections. The implemen- of landraces, 64% of improved varieties and 82% of tation of the recommendations following strategic the breeding lines are not available for distribution. priorities would substantially support the conservation Among the reasons are insufficient number of seeds/ of potato germplasm and its use in breeding and in tubers/in vitro plants, inadequate plant health status, situ conservation programs. packaging and shipping processes and difficulties in obtaining phytosanitary certificates. The terms Recommended strategic priorities: and conditions of the International Treaty on Plant • Comprehensive genotyping (sequencing) of ex situ Genetic Resources for Food and Agriculture apply to and/or in situ collections most (21 genebanks) but not to all potato collections, • Harmonization of potato taxonomy i.e. ARG1347, CHL028, COL017, GTM001. Therefore, • Documentation and monitoring of in situ popula- most material is provided with the standard mate- tions and traditional landraces maintained on farm rial transfer agreement (SMTA) by larger collections in American countries such as USA004, PER001, DEU159 and is available at • Capacity building for in situ conservation and national (46%) and international level (37%). Never- improved strategic concepts for on farm conserva- theless, in the last three years, only 2% was requested tion at the national and 16% at the international level by • Collecting missions and linkage between in situ/on domestic users, academic researchers, farmers and farm and ex situ conservation breeders. The limited availability of data and material • Capacity building to maintain high quality ex situ may restrict users’ ability to search and request suit- collections, in particular in Latin American countries able material. • Cryopreservation to ensure long-term survival of potato genetic resources Characterization and evaluation. Sequenced, • Further digitalization, better linkage and visibility well-characterized and evaluated potato germ- of publicly available data for ex situ and in situ plasm is a prerequisite for future breeding progress conservation management because potato productivity can only be maintained • Accessibility of collections for breeding and use and increased by using new breeding tools such as • Networking and training GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 7 8 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Potatoes being sold at market in Huancayo, Peru. Photo: Michael Major/Crop Trust 1 INTRODUCTION AND STRATEGY BACKGROUND Cultivated potato, commonly Solanum tuberosum L., is this cultural heritage has increased and indigenous the third most important crop for human consumption farmers and agrobiodiversity guardians support the and is grown on 16.5 million ha globally (FAOSTAT, cultivation, conservation and marketing of traditional 2021b). In the last 60 years, production volume has potato landraces. However, due to economic and increased by 37% and further increases are expected, political challenges of these countries, in situ conser- particularly in Asian and African countries, due to a vation is not substantially supported and more efforts higher harvest index and better water use efficiency are required to ensure the long-term maintenance of compared to cereals (Monneveux et al., 2013; Haver- potato landraces, their wild relatives and associated kort and Struik, 2015). Due to the predominantly biodiversity and habitats, i.e. establishment of pro- clonal propagation of cultivated potatoes, its produc- tected areas and economic support to farmers. tion can be severely affected by pest and diseases. The European and Mediterranean Plant Protection Orga- As a complementary approach, more than 80,000 nization (EPPO) has identified 19 quarantine pests potato accessions have been conserved in about 89 ex (EPPO, 2021) each of which can cause up to 100% situ genebanks (WIEWS, 2021). To conserve the great loss in potato production. In addition, climate change diversity of potato resources, a combination of seed scenarios predict changes in temperature and precipa- storage, field genebanks, in vitro storage and cryo- tion patterns in some major potato production areas preservation is used. Although genebank operations resulting in increased incidences of pests, diseases and have been optimized in recent decades (FAO, 2014), abiotic stresses by the end of the century (Raymundo the management of a potato collection is particularly et al., 2018). Problematically, the introduction of stress challenging because seed production from wild spe- resistances in new varieties remains a challenge and cies can be problematic due to self-incompatibilities, no major yield improvements have been achieved over and cultivated potato accessions require clonal propa- the last 100 years (Douches et al., 1996). The heterozy- gation in the field or in vitro, which is time consuming gosity of the tetraploid cultivated potato (AAAA, 2n and vulnerable to environmental stresses. In addition, = 4x = 48, haploid genome size 844 Mb), self-incom- for optimal use of potato diversity, comprehensive patibilites common in wild species, sterility barriers information on accessions needs to be publicly avail- and inbreeding depression have been major hurdles able, which requires a substantial investment in staff for potato breeding. Nevertheless, new tools such training and infrastructure. as marker-assisted selection, molecular prediction, hybrid breeding, inbreeding and genomic engineering To support the efficient and effective conservation create new opportunities to adapt potato varieties to and use of potato diversity, the Crop Trust initiated more stressful conditions and to achieve significant and facilitated the assessment of the conservation yield gains. Fundamental to all these approaches is status of potato and the identification of strategic the use of potato genetic resources. Therefore, these priorities. A survey was sent out in 2020 and 2021 resources must be securely conserved in situ and ex and the current literature was carefully reviewed and situ and be made available and accessible to breeders summarized. Based on the response of 32 genebanks and researchers. located in Asia, Europe, Latin America and North America, data obtained from (WIEWS, 2021), FAOStat, Wild potato species of the Solanum section Petota are peer-reviewed publications, personal communica- native to the Americas, with the highest diversity of tions and a virtual meeting (10–12 November 2021) species in Mexico and Peru (Hijmans et al., 2007). At attended by key stakeholders, the present ‘Global high altitudes, under short-day conditions and mod- Strategy for the Conservation of Potato’ provides a erate temperatures, Andean farmers used the great comprehensive overview covering the current status diversity of wild potato species for domestication and and needs of potato collections. To ensure long-term contributed substantially to the diversity of potato conservation of potato genetic resources and their use landraces that are still grown today. More than 3,000 for breeding, 10 strategic action priorities have been traditional landraces are estimated to be cultivated identified. Their implementation would significantly in the Andes and the Chiloé islands (Spooner et al., benefit the active conservation and use potato genetic 2014). Fortunately, in the last 20 years, awareness of resources and contribute to global food security. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 9 2 ORIGIN, DOMESTICATION AND CENTERS OF DIVERSITY Potato was domesticated in the South American Andes genebanks, due to various crossing barriers, diploids about 8,000 to 10,000 years ago (Ovchinnikova et al., and most polyploids are usually preserved as seeds 2011) and distributed around globe during post-Co- reproduced in heterozygous populations. However, lumbian times. According to Hawkes (1990), Solanum some collections, i.e. triploid and pentaploid wild tuberosum L. is used for the tetraploid indigenous cul- potato species, require the conservation of clonal tivated populations, also termed landraces, grown in propagules. lowland Chile and the high Andes. The last taxonomic classification (Spooner et al., 2007; Ovchinnikova et Landrace . The term ‘landrace’ was first mentioned at al., 2011) includes di-, tri- and tetraploid landraces the International Congress of Agriculture and For- grown in the high Andes (‘Andigenum group’) as estry in Vienna in 1890 (Zeven, 1998). It is defined well as the Chilean tetraploid landraces (‘Chilotanum as a cultivated, heterogeneous variety selected in a group’). Nowadays, S. tuberosum is the name applied specific ecogeographical area and well adapted to to advanced potato varieties that have undergone edaphic and climatic conditions and to traditional intensive plant breeding during the last 200 years. management and use there. However, due to con- tinuous evolution and further natural and artificial 2 .1 Definition of wild species, land- selection, the definition of ‘landraces’ has been races, improved varieties reconsidered several times since then. Casañas et al. (2017) suggest that the term ‘landrace’ should be used Wild species . Di-, tri-, tetra-, penta-, hexaploid wild for cultivated varieties that have evolved through species from the Solanum section Petota, native to the conventional but also modern breeding technologies Americas, are considered. These comprise 228 species in a traditional or modern agricultural environment according to the taxonomy of Hawkes (1990) and 107 within a specific ecogeographical area. With regard species following the classification system proposed to potato germplasm, we consider as landraces the by Spooner et al. (2014). In nature, wild potatoes cultivated varieties evolved in South America, namely reproduce by both sexual and clonal propagation. In the landraces of the ‘Andigenum group’, ‘Chilotanum 10 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Farmer with potatoes for planting, Colmar, Peru. Photo: Michael Major/Crop Trust group’ and those belonging to the highland bitter commercial companies are considered as improved potato species. Furthermore, non-commercial heterog- varieties maintained as clonal plants. enous varieties adapted to farming systems which may have been introgressed from genetically improved Breeding lines . Potato breeding lines can be under- varieties (Figure 2.1.1) or other landraces in a partic- stood as more or less homogenous, di- or polyploid ular ecogeographical area in Africa, America, Asian, potato plants, which are the result of crossing activi- Europe and Oceania are also considered as landraces. ties between different varieties, landraces, and intro- In addition, ‘heirloom varieties’ that have undergone gression of wild species by using modern breeding conservative selection and may have remained free technologies. These are maintained as clonal plants, from introgression are also considered as landraces. In usually highly selected and only available for a short order to maintain the specific genotype, this germ- time. plasm is often maintained as clonal plants, but can also be preserved as seed. 2 .2 Domestication process Improved varieties including modern and commercial Solanum tuberosum ‘Andigenum group’. The domes- varieties, are generally very homogenous and widely tication of cultivated potato has been considered as available without reference to specific ecogeograph- a series of events (Figure 2.2.1) which began around ical areas, and are managed by breeding companies Lake Titicaca at 3,000 to 4,000 m altitude with high and cooperatives (Casañas et al., 2017). Regarding light intensity and temperatures between 10 and 20°C potato germplasm, all modern varieties that are very (Grun, 1990). Andean landraces are considered to be homogenous and have been distributed widely by descended from members of the Solanum brevicaule Breeding Improved Evolved Heirloom Wild species lines variees Landraces varie es Breeding 1970 lines 1950 Wild species Improved Landraces varie es 1900 Landraces ‚Highland bi er potatoes‘ Landraces ‚Chilotanum group‘ Landraces 8,000 ‚Andigenum group‘ to M. Nagel (2022) 10,000 years ago Wild species Figure 2 .1 .1 . Historic relationship between wild potato species, landraces, improved varieties, breeding lines and heirloom varieties. Color code is based on Figure 2.2.1 and refers to the most prominent haplotype frequency present in the different landraces. Figure adapted for potato is based on Casañas et al. (2017). GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 11 Wild progenitors Landraces Today‘s varie es Solanum tuberosum ’Andigenum group‘ 3x S. demissum 2x (GUA, MEX) 2x 4x S. stoloniferum 2EBN 2EBN 4EBN (MEX, USA) 6x 4EBN 4x Adapta on to short-day, 4EBN S. candolleanum s.l. high light intensity & humidity, cool temperatures, Today‘s varie es (PER) high gene c diversity , are hybrids*³,⁴ 2x Western Venezuela - Northern Argen na 2EBN *3 4x Solanum tuberosum ’Chilotanum group‘ 4EBN S. brevicaule s.l. ? 3x (ARG, BOL, PER) 2x 4x 2EBN 4EBN 3x ? Long-day adapta on, S. berthaul i low gene c diversity , (ARG, BOL) 2x Southern Chile, Argen nian valley Adapta on to S. maglia ’Highland bi er potato‘ species - long-/ neutral day (ARG, CHL) - moderate climate Frost-resistant, high glycoalkaloid levels - low glycoalkaloid content Andes highlands of southern Peru and Bolivia - increase in tuber size *1 *2 - tolerances against 4x 2x stress & diseases 2EBN 5x 2EBN 2x 3x 2EBN M. Nagel (2022) S. acaule S. boliviense S. anjanhuiri S. curlobum (ARG, BOL, PER) (ARG, BOL, PER) (BOL, PER) (BOL, PER) S. juzepczukii (ARG, BOL, PER) Figure 2 .2 .1 . Origin of modern potatoes including potential hybridization and domestication events. Solid arrows show putative hybridization events, broken lines indicate natural variation and anthropogenic selection. Figure and data are adapted from Gavrilenko et al. (2013) and Spooner et al. (2014). *1 Hybridization with diploid members and a *2 tetraploid members of the ‘Andigenum group’. Colors represent different plastid SSR haplotypes: Black, unique haplotypes; Grey, Rare haplotypes VII, IX to XXIII found in various combinations in the wild species-progenitors (Gavrilenko et al., 2013); Yellow, plastid SSR haplotype I; Red, plastid SSR haplotype III of the Solanum berthaultii (=S. tarijense); Blue, plastid SSR haplotype II; Brown, plastid SSR haplotype IV; Pink, plastid SSR haplotype V; Purple, plastid SSR haplotype VIII; Light Purple, haplotype W/gamma introduced from Solanum stoloniferum Schltdl. according to Hosaka and Sanetomo (2012) and Sanetomo and Gebhardt (2015) (*3); Green, plastid SSR haplotype VI; Light green, haplotype D introduced from Solanum demissum Lindl. according to Hosaka and Sanetomo (2012) and Sanetomo and Gebhardt (2015). Solanum candolleanum Berthault s .l ., northern members of the S. brevicaule complex; S. brevicaule s .l ., southern members of the S. brevicaule complex. s.l., sensu lato; *4 Gavrilenko et al. (2019b). Bitter complex, specifically from those with the plastid s.l. (southern members of the S. brevicaule complex) SSR haplotype I [yellow, (=P cytoplasm type according and Solanum candolleanum Berthault s.l. (northern to Hosaka and Sanetomo (2012), Figure 2.2.1], that is members of the S. brevicaule complex), respectively. common in diploids of the ‘Andigenum group’ and In the latter group, Spooner et al. (2014) merged endemic to central Peru, Bolivia, and northern Argen- 32 taxa accepted by Hawkes (1990). AFLP analysis tina (Ugent, 1970; Spooner et al., 2005; Hosaka and (Spooner et al., 2005) supported a monophyletic origin Sanetomo, 2012; Gavrilenko et al., 2013). Members of the Andean landraces from the northern members of the S. brevicaule complex are diploid, tetraploid of the S. brevicaule complex. Further hybridization, or hexaploid (Ochoa, 1990; Spooner et al., 2014) and polyploidization, natural variation and selection led according to Hawkes (1990) have been described by to the great morphological and genetic diversity of 19 taxonomic names. Based on the morphological and the Andean landraces, termed Solanum phureja Juz. genetic similarity, Spooner et al. (2014) and Spooner & Bukasov, Solanum stenotomum Juz. & Bukasov, et al. (2016) lumped 18 names into in S. brevicaule Solanum chaucha Juz. & Bukasov, S. tuberosum (Table 3.2.1), which increased to 35 synonyms in subsp. andigena following the classification system of the monographic treatment of wild potatoes of the Hawkes (1990) or S. tuberosum ‘Andigenum group’ Southern America (Spooner et al., 2016; Spooner et following Spooner et al. (2014). The di-, tri-, tetraploid al., 2019). Although genetic marker analysis did not landraces are widespread and can be found from clearly distinguish groups, two geographical subsets, western Venezuela to northern Argentina (Ovchin- the Bolivian/Argentinian populations and the Peru- nikova et al., 2011). vian populations, were recognized as S. brevicaule 12 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Solanum tuberosum ‘Chilotanum group’ . Further that these wild species are the maternal ancestors of domestication events were studied based on two S. ajanhuiri (2n = 2x = 24) and S. juzepczukii. Plastid hypotheses: (1) the multiple origin hypothesis and (2) SSR data also indicated the multiple maternal origin the restricted origin hypothesis. Under the multiple from reciprocal crosses for these two highland bitter origin theory, Juzepczuk and Bukasov (1929) hypoth- cultivated species. By contrast, the pentaploid S. cur- esized that S. tuberosum sensu stricto according tilobum might have a monophyletic maternal origin to these authors [= Solanum tuberosum subsp. because the plastid SSR haplotype I was present in tuberosum according to the nomenclature of Hawkes all studied accessions of S. curtilobum (Gavrilenko (1990), or Solanum tuberosum ‘Chilotanum group’ et al., 2013). Furthermore, S. curtilobum might have using the system of Spooner et al. (2007)] evolved arisen by hybridization of ‘Andigenum group’ dip- from wild tetraploid species, i.e. Solanum fonckii Phil. loids x S. juzepczukii, by ‘Andigenum group’ triploids ex Reiche (a nomen nudum), Solanum leptostigma x S. acaule, or by ‘Andigenum group’ tetraploids x S. Juz. and Solanum molinae Juz. native to Chiloé juzepczukii, as in all such crosses unreduced gametes Island. Hawkes (1990) considered S. leptostigma and can arise (Gavrilenko et al., 2013). S. molinae as synonyms for S. tuberosum, whereas Ovchinnikova et al. (2011) suggested that they are 2 .3 Domestication traits plants of the ‘Chilotanum group’ and not wild species’ progenitors, supporting the ‘restricted origin hypoth- Natural selection and domestication had an enor- esis’ of Hawkes (1990) and Grun (1990). According mous impact on the genome arrangement of today’s to this, the ‘Chilotanum group’ evolved from the potato. Meyer and Purugganan (2013) have identified ‘Andigenum group’. Using AFLP data, Spooner et al. 15 traits of root and tubers crops relevant for domes- (2005) confirmed that all potato landrace popula- tication and diversification. Key traits for domes- tions descended from the northern component of the tication include flavor, resource allocation, starch S. brevicaule complex, arguing for an origin from a content, ability to thrive in modified landscapes, single species or its progenitor. However, unlike the and reduced branching, all of which are relevant to ‘Andigenum group’, landraces of the ‘Chilotanum potato. Sequencing of a potato diversity panel of group’ have T-type cytoplasm (Hosaka, 2002; 2003) 67 genotypes/accessions including modern varieties, or cpSSR haplotype III (Gavrilenko et al., 2013). South American landraces and wild diploid species, Therefore, putative wild maternal ancestors of the revealed that more than 2,600 genes were under ‘Chilotanum group’ are populations of S. berthaultii strong selection pressure (Hardigan et al., 2017). One having this plastid cytoplasm type. Plants of a poten- of the most important adaptations was the transition tial maternal ancestor (S. berthaultii) and plants of from short-day conditions in the equatorial region to the tetraploid ‘Andigenum group’ might have reached tuber formation under temperate southern Chilean together the Chilean coast and the Argentinian valley and later European long-day conditions. Kloosterman of Mendoza Province, where they found ideal growing et al. (2013) identified the StCDF1 gene (Solanum conditions (Spooner et al., 1991). Further reproduction tuberosum CYCLING DOF FACTOR1) located on chro- might have been entirely via tubers, which explains mosome 5 as a candidate for controlling plant matu- the low genetic diversity. However, microsatellite rity and the onset of tuberization. Natural allelic vari- studies of Spooner et al. (2012) and Gavrilenko et al. ants of StCDF1 alleles indicated that StCDF1 protein (2013) revealed discrepancies in the further position structure has been disrupted by TE-induced (StCDF1.2) of Solanum maglia Schltdl. as a wild progenitor and and non-TE-induced mutations (Hardigan et al., 2017) hence, the full background of the ‘Chilotanum group’ leading to tuberization outside equatorial short-day remains to be elucidated. conditions. Highland bitter potato species . Solanum curtilobum Other important gene signatures have been identified Juz. & Bukasov (2n = 5x = 60) and Solanum juzep- for tuber enlargement specifically affecting cell cycle, czukii Bukasov (2n = 3x = 36) contain high glycoalka- circadian rhythm and sucrose transport and mobiliza- loid levels and are commonly used for freeze-drying tion, including effects on sucrose-phosphate synthase, (Hawkes, 1962). In total, three frost-resistant spe- sugar transporters, fructokinase, inorganic pyrophos- cies of cultivated potato (Solanum ajanhuiri Juz. & phatase proteins and shifts to sucrose synthase (Susy) Bukasov, S. curtilobum and S. juzepczukii) evolved activities (Hardigan et al., 2017). Furthermore, in from the ‘Andigenum group’ and are involved in potato, glycoalkaloids are an important component introgression with the wild species series Solanum of the plant defense mechanism and comprise mainly acaule Bitter and Solanum boliviense Dunal in DC. a-solanine and a-chaconine in commercial varieties (Bukasov, 1933; Hawkes, 1962; Schmiediche et al., (Kuhn and Low, 1954). The presence of glycoalka- 1982; Ovchinnikova et al., 2011; Spooner et al., 2014). loids can cause acute toxic effects and the lowest Nuclear DNA sequence data (Rodriguez et al., 2010) observed adverse effect level is considered to be 1 mg and plastid SSRs (Gavrilenko et al., 2013) supported total potato glycoalkaloids kg-1 body weight per day. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 13 Although the content can be reduced by up to 90% chromosomes of x = 12 and ranges are shown for dip- (EFSA et al., 2020) by peeling, boiling, frying in oil, loid (2n = 2x = 24), triploid (2n = 3x = 36), tetraploid selection was made for lower glycoalkaloid levels. (2n = 4x = 48), pentaploid (2n = 5x = 60) and hexaploid Nowadays, most potato varieties contain less than 5% (2n = 6x = 72) species (Figure 2.4.1.1, Table 4.2.1). of total glycoalkaloid contents in tubers (Milner et al., 2011). For 187 wild potato species, Hijmans et al. (2007) analyzed 5,447 reports of ploidy determination and 2 .4 Geographic distribution and centers found that 123 species were diploid (green, Figure of diversity 2.4.1.1). These species covered the largest geograph- ical range and were predominantly present at the Potatoes can generally be grown in climates where extreme northern (southwestern USA) and/or southern temperature during tuber formation and bulking (Argentina, Chile, Uruguay) latitudes of the wild ranges between 4 and 18°C and temperatures for potato distribution range. Forty-three species were optimal plant development are below 30°C (Hammes exclusively polyploid. Of both groups, 30, 20, 14 and and De Jager, 1990; Griffin et al., 1993; Raymundo two species contain tetraploid, triploid and hexaploidy et al., 2018). Therefore, potato is grown at latitudes and pentaploid populations, respectively. Triploids between 69° N to 50° S and up to 4,000 m altitude and pentaploids cover a smaller area than tetraploids (Hijmans, 2003), covering 17.3 million ha during and hexaploids. Tetraploids (yellow, Figure 2.4.1.1) are the frost-free period of the temperate zones, in the dominant in northern Mexico, Ecuador and Peru down highlands of the tropics i.e. in the Andes, Eastern to northern Argentina. S. acaule is especially common Brazilian highlands, the African highlands and the in the latter two areas in South America and Solanum volcanic mountains of Southeast Asia, and during the stoloniferum Schltdl. in North and Central America. heat-free period of the subtropics i.e. the Mediterra- In contrast, triploids appear more in the extreme dry nean, southern China and northern India (Devaux et and warm areas, especially at the south-eastern end al., 2020). The wild species are native to the Amer- of wild potato distribution but records are relatively icas and are found only between the southwestern rare. Some species were observed to have even three United States and the southern end of South America cytotypes, i.e. Solanum verrucosum Schltdl. was pre- (Hawkes and Hjerting, 1969). South American land- dominantly diploid, but triploids and tetraploids were races are found on farms between western Venezuela also observed (Hijmans et al., 2007). However, data and northern Argentina, on Chiloé Island and the produced by Hawkes (1990) and Spooner et al. (2014) adjacent Chonos Archipelago of south-central Chile. suggest that diploid wild potatoes evolved in Mexico and spread to South America. The many polyploids in Wild species northern Peru also suggests that species diversified a long time ago (Hijmans et al., 2007). Wild species are widespread from the southwest of the USA (Arizona, Colorado, New Mexico, Texas, Hijmans and Spooner (2001) determined the number Utah), through the tropical highland of Mexico, of wild species per country by analysing 6,073 georef- Central America and the Andes down to Argentina, erenced observations. These data were complemented Chile and Uruguay. They occur in a range of environ- by Spooner et al. (2014), who analyzed 11,485 georef- ments between 38° N and 41° S but are usually found erenced data and confirmed that Peru is the country in cool climates, in the tropical lowlands at average with most (51 wild species) but also highest number temperatures above 20°C and at altitudes between of rare species (13) with fewer than five observations 2,000 and 4,000 m (Hijmans and Spooner, 2001). In (Figure 2.4.1.2). Mexico, Argentina and Bolivia have these areas, rainfall is usually less than 800 mm. Except 27, 17 and 16 wild species, respectively, with 13 species for Solanum morelliforme Bitter & Muench, which is rare in Mexico. Dependent on the type of study and endemic in oak and pine forests, and Solanum clarum time of publication, these numbers can vary, overall Correll, which can be epiphytic and grows among species richness is highest between central to northern mosses, all potato species are terrestrial and morpho- Peru, identifying this country as the primary center for logical discrimination can be very difficult (Hijmans et species richness and diversity (Figure 2.4.1.1, 2.4.1.2) al., 2002). Many of them have a similar appearance and Mexico as secondary center of diversity. and show dissected leaves, corollas in different shades of white, blue, purple and pink, and pentagonal Peru. North-central Peru, especially the departments or rotate in shape, and spherical to ovoid berries of Amazonas, Cajamarca, La Libertad and San Martín, (Hijmans and Spooner, 2001). Due to the difficulties in is recognized as a diversity hotspots of Solanaceae identification and complex taxonomy, the delineation (Stern et al., 2008). For example, in the Cajamarca of distribution areas is problematic. Hijmans et al. department, nine species comprising Solanum caja- (2007) estimated ranges based on ploidy levels. The marquense Ochoa, Solanum contumazaense Ochoa, species of the Petota section have a basic number of Solanum guzmanguense Whalen & Sagást., Solanum 14 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Diploid Triploid Tetraploid Pentaploid Hexaploid Figure 2 .4 .1 .1. Geographical distribution of wild species with different levels of ploidy. The colored areas represent distribution of 2x, 3x, 4x, 5x and 6x species and are based on data of Hijmans et al. (2007). Shaded areas indicate centers of diversity in Peru and Mexico. 60 Total number of species 50 Endemic species Rare species 40 30 20 10 0 Figure 2 .4 .1 .2. Distribution of wild potato species in America. The total number of species observed (grey), the number of endemic (black) and rare species (red) with fewer than five reports and the number of observations (above the column) are presented. A few overlaps between endemic and rare species were ignored. The figure is based on data of Spooner et al. (2014). GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 15 Number of wild species Peru 2,440 Mexico 2,562 Argenna 4,547 Bolivia 1,740 Ecuador 226 Colombia 165 Guatemala 135 Brazil 111 Chile 85 Honduras 10 Uruguay 187 Panama 12 Paraguay 121 M . Nagel (2022) USA 608 Costa Rica 143 Venezuela 23 hypacrarthrum Bitter and Solanum lopezcamareane as The difference in numbers may be due to different well as Solanum jalcae Ochoa (endemic to La Lib- taxonomic classifications. These wild species occupy ertad), Solanum raquialatum Ochoa (endemic to the mainly the Andean valleys and the subtropical Andean entire Amotape-Huancabamba Zone) and Solanum rainforest (Yungas), where they normally occur at alti- chomatophilum Bitter and S. tuberosum were tudes between 700 and 4,500 m (Ochoa, 1990). They reported. do not grow in the tropical lowland forests (Spooner and Bamberg, 1994). S. circaeifolium and S. soestii are Mexico. A national inventory of the priority crop wild considered to be rare (Coca, 2020). The more abun- relatives was conducted for Mexico (Contreras-Toledo dant S. circaeifolium is considered as endemic in the et al., 2018), including 20 of the 27 Solanum species North of the department of La Paz, and is threatened endemic to the country. In particular, two wild potato by deforestation and urbanization. S. soestii also has species (Solanum cardiophyllum Lindl. and Solanum limited distribution in the Department of La Paz and ehrenbergii (Bitter) Rydb.) are being conserved in situ is threatened with extinction due to drastic changes in (Contreras-Toledo et al., 2019). Thereby, Contreras-To- native vegetation due to eucalyptus plantations (Coca, ledo et al. (2019) recommended potential priority 2020). areas where plants of S. cardiophyllum should be col- lected first. These include the states of Aguascalientes, Landraces Hidalgo, Jalisco, State of Mexico, Michoacan, Morelos, Oaxaca, Puebla, Queretaro, Sinaloa, Zacatecas, and More than 3,000 landraces are maintained by indig- Mexico City. Plants of S. ehrenbergii are recommended enous farmers in the Andes and the Chiloé island to be collected in Aguascalientes, Guanajuato, (Spooner et al., 2014). Compared to the wild potato Hidalgo, Jalisco, State of Mexico, Michoacan, Nayarit, species, no specific habitats for different ploidy vari- Puebla, Queretaro, San Luis Potosi, Zacatecas, and ants could be identified for the traditional landraces, Mexico City. although the distribution of the S. tuberosum ‘Chi- lotanum group’ in Chile and extreme northern and Argentina . Seventeen wild potato relatives are southern range extensions of the ‘Andigenum group’ found in Argentina (Spooner et al., 2016; Palchetti are well-known (Spooner et al., 2010). In Mexico and et al., 2020), of which seven are considered endemic Central America, landraces were introduced during (Solanum xaemulans Bitter & Wittm., Solanum colonialization (Ugent, 1968). xbrucheri Correll, Solanum kurtzianum Bitter & Wittm., Solanum neorossii Hawkes & Hjert., Solanum Landraces can be grouped according to their market xrechei Hawkes & Hjert., Solanum venturii Hawkes presence and tuber characteristics (De Haan and & Hjert., and Solanum vernei Bitter & Wittm.) and Rodriguez, 2016). So-called commercial or cosmopol- ten as native (S. acaule, S. berthaultii, S: boliviense, itan landraces cover large areas of cultivation and are S. brevicaule, Solanum chacoense Bitter, Solanum well-known among consumers. In Peru and Colombia, commersonii Dunal, Solanum infundibuliforme Phil., the diploid ‘Peruanita’ and the ‘Criollo Amarilla’ are S. maglia, Solanum malmeanum Bitter and Solanum important landraces (Table 2.4.2.1). In Argentina, the microdontum Bitter). Wild potato populations were tetraploid ‘Tuni’ is offered in specialty restaurants identified in different protected areas by Clausen et (De Haan and Rodriguez, 2016). Another category al. (2018) and Kozub et al. (2019). comprises thousands non-commercial and floury, non- bitter landraces. These landraces are diverse and show Bolivia . Although Spooner et al. (2016) identified 16 great differences in shape, and skin and tuber color wild potato species in Bolivia (Table 3.2.1), Cadima (Ovchinnikova et al., 2011). De Haan and Rodriguez et al. (2014) listed 21 endemic potato wild relatives, (2016) identified hotspots of diversity in Huancavelica including Solanum achacachense Cárdenas, Solanum (Peru), Paucartambo (Peru), northern La Paz (Bolivia), alandiae Cárdenas, Solanum arnezii Cárdenas, and northern Potosí (Bolivia). A third category of Solanum avilesii Hawkes & Hjert., S. berthaultii, S: native bitter landraces belong to S. juzepczukii and boliviense, Solanum bombycinum Ochoa, S. brevi- S. curtilobum and are grown in central and southern caule, Solanum circaeifolium Bitter, Solanum xdoddsii Peru and Bolivia. They are bitter, often frost resistant Correll, Solanum flavoviridens Ochoa, Solanum and the frozen tubers are used for chuño, moraya gandarillasii Cárdenas, Solanum hoopesii Hawkes or tunta. The degree of bitterness can vary and can & K.A. Okada, Solanum xlitusinum Ochoa, Solanum be also present in genotypes of S. ajanhuiri and neocardenasii Hawkes & Hjert., Solanum neovavilovii varieties of the ‘Andigenum group’. In this case, the Ochoa, Solanum soestii Hawkes & Hjert., Solanum products are used for freeze-drying. Further details sucrense Hawkes, Solanum ugentii Hawkes & K.A. on landraces and in situ conservation are provided in Okada, Solanum violaceimarmoratum Bitter and Chapter 5. Solanum virgultorum (Bitter) Cárdenas & Hawkes. 16 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO 2 .5 Geographical spread and the rise of the Spanish into their Castilian language. In Chile, the modern varieties word for potato is ‘poni’ (Ugent, 1968; Hawkes and Francisco-Ortega, 1993). After its arrival in Europe, dif- Spanish explorers were most likely the first Europeans ferent words were used to the crops in different lan- to discover the potato in the tropical lowlands of guages. The word ‘tartouffli’ (truffle) in Italy was fur- Colombia when they arrived in the Magdalena River ther developed into ‘Kartoffel’ in Germany. The Czech Valley in 1536, as reported by Juan de Castellanos word ‘brambor’ and the Croatian word ‘krumpir’ (Spooner et al., 2014). The first tubers were likely come from the Southern German dialect ‘Gromberen’ brought from the Andes to the Canary Islands in or ‘Grundbirne’ (ground pear) and the French and approximately 1562 (Figure 2.5.1, No 1), where they Dutch terms ‘pomme de terre’ and ‘aardapple’ refer to were cultivated and propagated for onward transport apples from the soil. to Europe. As the Spanish name for potato (patata) is very similar to sweet potato (batata), the inter- The arrival of potatoes in continental Europe rep- pretation of historical records can be difficult. How- resents a milestone in the geographical spread of the ever, the Spanish word ‘patata’ and the English term crop (Hawkes and Francisco-Ortega, 1993). Among the ‘potato’ were likely derived from the Quechua-Inca early records is a shipment from the Canary Islands to word ‘papa’ which was adopted and transformed by Rouen, France, in 1574 (Figure 2.5.1, No 3). Salaman 6 10 9 Bermuda 7 Virginia (USA) (1620) 5 11 8 3 12 14 2 1 Figure 2 .5 .1 . Important events for the global potato distribution. Table 2 .4 .2 .1 . Diversity of potato landraces from centers of origin. Modified from De Haan and Rodriguez (2016) Approximate total Country in situ diversity Well-known commercial or Well-known of landraces cosmopolitan landraces bitter landraces Argentina 50–70 Chacarera, Tuni, Perija, Negrita, Collareja, Churqueña, Waicha Bolivia 1000–1500 Alqa Imilla, Yana Imilla, Yuraq Imilla, Imilla Rosada, Waycha Azul Luki, Wila Luki, Laran Luki, Paceña Qanqu Chuqipitu Chile 300–400 Michuñe Roja, Michuñe Negra, Michuñe Blanca, Cabra, Murta, Clavela Colombia 180–240 Criolla Amarilla, Tuquerreña, Carriza, Argentina, Salentuna, Colombina, Bandera, Mambera, Ratona, Tornilla Yema de huevo, Uvilla, Leona Blanca, Leona Negra, Coneja Ecuador 350–450 Negra, Coneja Blanca, Puña, Bolona, Jubaleña, Chaucha Amarilla Peru 2800–3300 Peruanita, Camotillo, Muru Huayro, Huayro, Macho, Yuraq Siri, Yana Siri, Piñaza, Huamantanga, Amarilla Tumbay, Amarilla del Centro, Ccompis Qanchillu, Locka Venezuela 30–40 Arbolona Negra, Cucuba, Tocana, Concha Gruesa, Tiniruca, Guadalupe GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 17 M . Nagel (2022) (1946) found evidence that cultivated potato left a compared to the late 18th century. The Irish potato northern port in South America and reached Spain famine between 1845 and 1847, caused by the late in 1569 (Figure 2.5.1, No 2) and was introduced to blight fungus (Phytophthora infestans) largely eradi- England (Figure 2.5.1, No 4) by Sir Francis Drake cated the predominant cultivated varieties, requiring in 1593 (Salaman et al., 1949). The first ‘European’ farmers to reintroduce older stocks which had a tetraploid potatoes originated in the Andes (Ames higher Andean background and were more tolerant and Spooner, 2008; Gutaker et al., 2019). Due to to the disease. However, only crosses between females adaptation to short-day conditions, the cultivation plants of Chilean potatoes and pollen of Andean of these plants in continental Europe must have potatoes have been successful and are responsible for been a challenge as tuber formation only started just most of today’s modern varieties combining nuclear before the onset of the cold season. To overcome the genes of andigenum and subsp. tuberosum with the short-day dependence on the continent, farmers most cytoplasmic factors of Chilean landraces (Grun, 1979). likely selected plants that adapted to local condi- Later, in the 20th century, intensive breeding programs tions. Gutaker et al. (2019) used historical herbarium introduced diversity from wild species, i.e. S. vernei, samples to show that plants with Chilean-related Solanum demissum Lindl. and S. stoloniferum and chlorotypes were also introduced from the 17th cen- northern-adapted strains of the ‘Andigenum group’, tury onwards. However, from 1600 onwards, potatoes to improve tolerance to the pathogen, rather than spread globally. The Portuguese shipped potatoes to using material descended from plants of the 19th cen- India (Figure 2.5.1, No 5) and the British to Sri Lanka tury (Ross, 1966; Grun, 1990; Hawkes, 1990; Spooner et (Graves et al., 2001). Dutch settlers introduced pota- al., 2014). toes to Penghu Islands, China (Figure 2.5.1, No 6) (De Haan and Rodriguez, 2016). In 1613, potatoes arrived Further information on the worldwide distribution in Bermuda (Figure 2.5.1, No 7) and reached Virginia and production of potato is provided in Chapter 4. in 1621 (Figure 2.5.1, No 8) (Graves et al., 2001). In the 18th century, Captain James Cook and Marion du In summary, molecular data have revealed, confirmed Fresne, introduced potatoes to New Zealand (Figure and supplemented earlier assumptions about the 2.5.1, No 9) and Australia (Figure 2.5.1, No 10) (De progenitors, distribution and global spread of our Haan and Rodriguez, 2016), and in the 19th, German modern potato. It could be shown that the progenitor and English settlers and missionaries brought the crop of the ‘Andigenum group’ derived from the northern to Africa (Figure 2.5.1, No 11) (Kiple and Ornelas, members of the S. brevicaule complex. Except for 2000). maternal ancestors of S. berthaultii, the wild ancestors of the ‘Chilotanum group’ are not yet fully elucidated, Until the end of the 17th century, the potato was although there is a strong proposal on the mono- hardly accepted as staple food in Europe. However, phyletic origin of this group, also tracing back to the as potatoes were hard to plunder during wars, the S. brevicaule complex. The great diversity of di-, tri-, Prussian King Frederick the Great promoted potato tetra-, penta- and hexaploid wild species forms the cultivation to farmers, who began to grow potatoes basis for a large number of landraces with different in small gardens. Besides, potatoes were very advan- tuber characteristics that evolved in the Andes and the tageous because they were hardly visible to the tax Chiloé Islands. In particular, the decline of glycoalka- collectors. Further, political promotion and field trials loids and the adaptation of plants of the ‘Chilotanum in various countries supported potato cultivation so group’ to long/neutral day conditions enabled the that by the beginning of 19th century, 120 potato further rise of the crop, which was shipped to conti- varieties had been documented in Europe (Stuart nental Europe and cultivated there in the 16th century. 1937; Zuckerman, 1998; Ames and Spooner, 2008). Political promotion and worldwide spread supported Examinations of the chlorotype frequencies of 88 the acceptance of the plant as a crop, which became individuals comprising landraces and modern varieties the third most important starchy staple in modern (Gutaker et al., 2019) showed that varieties carrying times. the Andean-related chlorotypes were reduced by half 18 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO 3 TAXONOMY Taxonomic classifications and descriptions are essential 3 .1 Historic background of potato guides for genebanks and their users and are particu- taxonomy larly important for characterization, regeneration/mul- tiplication, distribution, gap analysis and collecting, Wild and cultivated potato belong to the Solanaceae and further breeding efforts. The organization of family, which includes 90 genera and 3,000 to 4,000 biological diversity is shaped by the ongoing develop- species that vary widely in growth habit, morphology ment and discussion of species concepts (Rapini, 2004; and ecology. About 1,000 to 2,000 species are mem- de Queiroz, 2005). So far, a large range of different bers of the genus Solanum, in the subfamily Sola- species concepts have been proposed with little agree- noideae, which have a basic chromosome number of ment among them (Hausdorf, 2011). The Biological x = 12 (Olmstead and Palmer, 1992; Olmstead et al., Species Concept, also called the Isolation Concept 1999). The wild and cultivated potato belong to the (Mayr, 1942), is the most influential and refers to the Solanum section Petota. This section has been shaped geographic model of speciation and also includes by various introgressions, interspecific hybridization breeding relationships. Rapini (2004) suggest that the events, and auto- and allopolyploidy. Because of integration of genetic results may lead to semantic sexual compatibility among many species, a combina- problems. The reason for this is that species are tion of sexual and asexual reproduction, and pheno- regarded as units of identification whereas geneticists typic plasticity, the Petota section shows a high degree regard populations as evolutionary units (Ehrlich and of morphological similarity among species (Spooner, Raven, 1969). In order to avoid further challenges and 2009). As a consequence, the biological concept of a to provide clarity, it is important that these concepts species proposed by Mayr (1942) is difficult to apply are further developed by incorporating available and led to many taxa being described and used syn- molecular results. onymously, leading to major inconsistencies between GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 19 Solanum tuberosum in Lehrbuch der Botanik, 1911 descriptions and authors. Therefore, while in the past but not other taxa, as they may have multiple origins 494 epithets have been used for wild and 626 for involving common species and continuing hybridiza- cultivated potato species, in the most recent classifica- tion events. Huamán and Spooner (2002) recognized tion only 107 wild and 4 cultivated potato species are all landrace populations as the botanical species S. accepted (Ovchinnikova et al., 2011; Spooner et al., tuberosum. This included eight cultivar groups: Ajan- 2014). huiri, Andigena, Chaucha, Chilotanum, Curtilobum, Juzepczukii, Phureja and Stenotomum. However, A first description of potato diversity was documented the further investigation of 742 landraces using SSR by Alefeld (1866). However, a more detailed taxo- markers resulted in a re-classification of this system. nomic classification was attempted by Russian taxon- In 2007, Spooner et al. (2007) and later Ovchin- omists, who used ecogeography as the main char- nikova et al. (2011) re-evaluated cultivated potatoes acteristic in combination with ploidy and analysis of and grouped them into four species, including: (1) morphological and physiological traits (Ovchinnikova S. tuberosum, with the ‘Andigenum group’ of upland et al., 2011). The first taxonomic treatment of culti- diploids, triploids and tetraploids Andean genotypes vated potatoes dates back to 1929. Based on studies and the ‘Chilotanum group’ of lowland tetraploid of the first germplasm collection of cultivated pota- Chilean landraces; (2) S. ajanhuiri (diploid); (3) S. toes, the Russian taxonomists Juzepczuk and Bukasov juzepczukii (triploid); and (4) S. curtilobum (pen- (1929) named and described 13 cultivated species. taploid). Overall, during the process of taxonomic Later, based on the complex intraspecific systems, classification and re-classification, potato landraces dating back to Vavilov (1922), Vladimir Lekhnovich have been assigned to 13 cultivated species (Juzepczuk recognized hundreds of subspecies, ‘convarieties’, vari- and Bukasov, 1929), 21 species (Lekhnovich, 1972), eties and forms (Lekhnovich, 1972). In 1978, Bukasov 17 species (Bukasov, 1978), 9 species (Ochoa, 1990), 7 re-classified the 13 species recognized by Juzep- species (Hawkes, 1990), one species with eight cultivar czuk and Bukasov (1929) into 17 cultivated species groups (Huamán and Spooner, 2002) and, currently, 4 (Bukasov, 1978). John (Jack) Hawkes learned about species, with one species including two cultivar groups this system during his visits to the All-Union Institute (Spooner et al., 2007; Ovchinnikova et al., 2011; of Plant Industry in Leningrad (now St. Petersburg) Spooner et al., 2014). (Ovchinnikova et al., 2011) and at first recognized 18 cultivated species (Hawkes, 1944). Later, he reduced 3 .2 Nomenclature them to 7 cultivated species and 228 wild potato species, divided in 19 taxonomic series (Hawkes, The combination of molecular studies and morpho- 1990). Although the Hawkes (1990) treatment was logical data obtained from different field surveys, not universally accepted (Huamán and Spooner, 2002), herbarium specimens, and plants grown in field pots potatoes were classified as distinct species under (Spooner et al., 2004; Spooner et al., 2016; Spooner the International Code of Botanical Nomenclature et al., 2019) led to extensive changes in the taxonomy (ICBN). However, under the International Code of of the section Petota [see Table 2 in Spooner et al. Nomenclature of Cultivated Plants (ICNCP), culti- (2014)] subsequent to Hawkes (1990). The re-classifica- vated potatoes were also treated as cultivar groups tion was driven in particular by the difficulty in identi- (Dodds, 1962; Huamán and Spooner, 2002; Spooner fying the species recognized by Hawkes (1990) and the et al., 2007; Ovchinnikova et al., 2011). As the clas- complex biological factors in this section, i.e. the lack sification and nomenclature of cultivated plants are of strong biological isolating mechanisms, interspecific supposed to follow the strict rules of ICNCP or ICBN, hybridization and introgression events, allopolyploidy potato taxonomy has been controversially represented and a combination of sexual and asexual reproduc- by different assumptions about the evolutionary tion. Overall, 107 wild species, instead of 228 species, dynamics of potato species (Huamán and Spooner, and four cultivated species, instead of 7 cultivated 2002). Moreover, the application of the biological con- species, were recognized by Spooner et al. (2014) and cept of species is very challenging to potato species the relationship with the Hawkes (1990) system is (Knapp, 2008). Nevertheless, a taxonomic treatment shown in Table 3.2.1 from Hawkes (1990). was elaborated, simplified and proposed extensively by Hawkes (1990) and is still used for classifications in Besides the morphological data, the degree of ploidy most genebanks. and putative phylogenetic relationship are essential taxonomic descriptors (Figure 3.2.1). The ploidy level Since the beginning of 21st century, high-throughput can support theories about the complex dynamics sequencing approaches have shed more light on the of polyploid genomes during evolution (Soltis et al., complex taxonomy of potato. In 2002, the phenetic 2004). Polyploidy can be considered either as an evo- analysis of potato landrace populations supported the lutionary dead-end (such as the case with triploids) or recognition of S. ajanhuiri, S. chaucha, S. curtilobum, evolutionarily advanced with enhanced physiological S. juzepczukii and S. tuberosum subsp. tuberosum properties, including improved stress tolerance due 20 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO to increased genetic variation and the buffer effect frost tolerant (of putative hybrid origin with the of duplicated genes (Van de Peer et al., 2021). In any frost-tolerant species S. acaule or Solanum megis- case, it is one of the most important criteria for plant tacrolobum Bitter) …continue with 2 systematics. The phylogenetic relationship shows 1. Plants are ascending to erect; pedicel articulation is the association between ingroups and outgroups, evident and located below the upper one-fifth of including the division of potato species into three the pedicel; not frost tolerant clades. The clades include all tuber-bearing potatoes ... continue with 4 and are based on a range of phylogenetic studies sum- 2. Most distal lateral leaflets are broadly decurrent; marized by Spooner et al. (2014). plants are diploid. • In clade 1+2, diploid species often have non-shiny See S. ajanhuiri. leaves, white stellate corollas, single tubers at the 2. Most distal lateral leaflets are not or only slightly end of stolons decurrent; plants are triploid or pentaploid • In clade 3, diploid species have shiny leaves, blue to … continue with 3 purple pentagonal corollas, moniliform tubers 3. Plants are low growing, 62 to 98 cm tall and trip- • In clade 4, diploid species have non-shiny leaves, loid. diverse colored pentagonal to rotate corollas, single See S. juzepczukii tubers at the end of stolons 4. Plants are of medium height, 96 to 125 cm tall and pentaploid. The polyploid wild species are often allopolyploids See S. curtilobum and difficult to identify based on specific morpholog- 4. Plants are adapted to short-day flowering and ical characteristics. Some of them have moniliform tuberization; upper leaves are diverged from stem tubes. Based on the molecular data, they are grouped at 40°–50°; plants are diploid, triploid or tetraploid. into four clades and 19 “informal species groups”, See S. tuberosum ‘Andigenum group’ including 11 groups for North and Central Amer- 4. Plants are adapted to long-day flowering and ican species, six groups for southern South American tuberization; upper leaves diverged from stem at species and three shared groups, i.e. Morelliforme, angle of 50°–90°. Landrace populations is native to Conicibaccata and Acaulia group (Spooner et al., 2004; south-central Chile. Spooner et al., 2014; Spooner et al., 2016; Spooner et See S. tuberosum ‘Chilotanum group’ al., 2019; Peralta et al., 2021). Based on morphological 5. Modern varieties are commonly breeding popula- characters, molecular data, and phylogenetic rela- tions of the Northern Hemisphere, that are grown tionships, two non-tuber-bearing series of the section worldwide; they may be hybrids of plants of the Petota in the Hawkes (1990) taxonomy – Etuberosa ‘Chilotanum group’ and ‘Andigenum group’ and Juz. and Juglandifolia (Rydb.) Hawkes – were re-classi- other cultivar groups fied and are now in the section Etuberosum (Bukasov See S. tuberosum & Kameraz) A. Child and the tomato clade comprising section Juglandifolia (Rydberg) A. Child and section Lycopersicoides A. Child (Peralta) (Peralta et al., 2008; Potato nuclear clade 1+2 Spooner et al., 2014). North and Central America Solanum morelliforme Cultivated potato species traditionally have been in Mexico, Central America with a classified as Linnaean taxa according to botanical disjunct popula on in Northern Bolivia nomenclature (Juzepczuk and Bukasov, 1929; Hawkes, 1944; Hawkes, 1956; Bukasov, 1978; Hawkes, 1990; Potato nuclear clade 3 Ochoa, 1990). Cultivated species can be distinguished Ecuador and Northern Peru on their morphology and ploidy level. Cultivated Potato nuclear clade 4 landraces were also treated as cultivar groups (Dodds, Solanum verrucosum 1962; Huamán and Spooner, 2002; Spooner et al., Mexican, South American diploids 2007; Ovchinnikova et al., 2011). Huamán and Spooner exclusive clade 3 (2002) proposed a key to the differentiation of Tomato clade landrace cultivar-groups. Later, these key and descrip- tions were modified by Ovchinnikova et al. (2011) as Solanum secon Etuberosum clade follows: 1. Plants are semi-rosette to semi-erect; pedicel Figure 3 .2 .1 . Three nuclear clades and outgroups (tomato and articulation is indistinct to only slightly distinct etuberosum) of the diploid species of Solanum section Petota. The polyploid species (allopolyploids) combine genomes of the and located in the upper one-fifth of the pedicel; three clades. Figure adapted from Spooner et al. (2014). GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 21 Table 3 .2 .1 . Accepted species of Solanum section Petota according to Spooner et al. (2014), (Spooner et al., 2016), (Spooner et al., 2019). Country of occurrence, ploidy level, endosperm balance number (EBN, see chapter 11.2), and nuclear-marker-based cladistic relationships as explained in Spooner et al. (2014) and species and synonyms accepted by Hawkes (1990) or subsequent authors. Genepools and priority levels were assigned based on data of Castañeda-Álvarez et al. (2015). Species that have the highest (H) priority for collecting are highlighted in blue. Medium (M) and low (L) priority are only indicated. More details are pro- vided online on Solanaceae Source (www.http://solanaceaesource.org/). Species name Taxon according to according to Genepool Priority levels Countries Ploidy level Nuclear Hawkes (1990) or Spooner et al . (2014) Clade subsequental authors Solanum acaule Bitter Primary ARG, BOL, PER, CHL 4x (2EBN) Complex4 S. acaule Bitter S. acaule f. incuyo Ochoa (1994b) S. acaule var. punae (Juz.) Hawkes Solanum acroglossum Juz. Secondary H PER 2x (2EBN) 3 S. acroglossum Juz. Solanum acroscopicum Ochoa Secondary H PER 2x [4] S. acroscopicum Ochoa S. lopez-camarenae Ochoa Solanum ×aemulans Bitter & Wittm. ARG 3x, 4x (2EBN) [4] S. × aemulans Bitter & Wittm. S. acaule subsp. aemulans (Bitter & Wittm.) Hawkes & Hjert. S. ×indunii K.A. Okada & A.M. Clausen Solanum agrimonifolium Rydb. Secondary M GUA, HON, MEX 4x (2EBN) 3+4 S. agrimonifolium Rydb. Solanum albicans (Ochoa) Ochoa L ECU, PER 6x (4EBN) 3+4 S. albicans (Ochoa) Ochoa S. acaule subsp. palmirense Kardolus (1998) Solanum albornozii Correll Secondary L ECU 2x (2EBN) 3 S. albornozii Correll Solanum amayanum Ochoa PER 2x (2EBN) 4 S. amayanum Ochoa Solanum anamatophilum Ochoa Tertiary PER 2x (2EBN) 3 S. anamatophilum Ochoa S. peloquinianum Ochoa Solanum andreanum Baker Secondary M COL, ECU 2x (2EBN), 4x (4EBN) 3 S. andreanum Baker S. burtonii Ochoa S. correllii Ochoa S. cyanophyllum Correll S. paucijugum Bitter S. regularifolium Correll S. serratoris Ochoa (1990b). S. solisii Hawkes S. suffrutescens Correll S. tuquerrense Hawkes Solanum augustii Ochoa Tertiary PER 2x (1EBN) 3 S. augustii Ochoa Solanum ayacuchense Ochoa Secondary H PER 2x (2EBN) 4 S. ayacuchense Ochoa Solanum berthaultii Hawkes Primary L ARG, BOL 2x (2EBN), 3x 4 S. berthaultii Hawkes S. flavoviridens Ochoa S. tarijense Hawkes S. ×litusinum Ochoa S. ×trigalense Cárdenas 22 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Species name Taxon according to according to Genepool Priority levels Countries Ploidy level Nuclear Hawkes (1990) or Spooner et al . (2014) Clade subsequental authors S. ×zudaniense Cárdenas Solanum ×blanco- galdosii Ochoa PER 2x (2EBN) 3 S. ×blanco-galdosii Ochoa Solanum boliviense Dunal in DC. Secondary L ARG, BOL, PER 2x (2EBN) 4 S. boliviense Dunal in DC. S. astleyi Hawkes & Hjert. S. megistacrolobum Bitter S. megistacrolobum f. purpureum Ochoa (1994b) S. sanctae-rosae Hawkes S. toralapanum Cárdenas & Hawkes Solanum bombycinum Ochoa Secondary H BOL 4x [3+4] S. bombycinum Ochoa Solanum brevicaule 2x (2EBN), Bitter Primary L ARG, BOL, PER 4x (4EBN), 4 S. brevicaule Bitter 6x (4EBN) S. alandiae Cárdenas S. avilesii Hawkes & Hjert. S. gourlayi Hawkes S. gourlayi subsp. Pachytrichum (Hawkes) Hawkes & Hjert. S. gourlayi subsp. saltense A.M. Clausen & K.A. Okada S. gourlayi subsp. vidaurrei (Cárdenas) Hawkes & Hjert. S. hondelmannii Hawkes & Hjert. S. hoopesii Hawkes & K.A. Okada S. incamayoense K.A. Okada & A.M. Clausen S. leptophyes Bitter S. oplocense Hawkes S. setulosistylum Bitter S. sparsipilum (Bitter) Juz. & Bukasov S. spegazzinii Bitter S. sucrense Hawkes S. ugentii Hawkes & K.A. Okada S. virgultorum (Bitter) Cárdenas & Hawkes S. ×subandigena Hawkes Solanum ×brucheri Correll ARG 3x [4] S. ×brucheri Correll S. ×viirsoii K.A. Okada & A.M. Clausen Solanum buesii Vargas Secondary H PER 2x (2EBN) 4 S. buesii Vargas Solanum bulbocastanum Dunal in Poir. Tertiary L GUA, HON, MEX 2x (1EBN), 3x 1 S. bulbocastanum Dunal in Poir. S. bulbocastanum subsp. dolichophyllum (Bitter) Hawkes S. bulbocastanum subsp. partitum (Correll) Hawkes GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 23 Species name Taxon according to according to Genepool Priority levels Countries Ploidy level Nuclear Hawkes (1990) or Spooner et al . (2014) Clade subsequental authors Solanum burkartii Ochoa Secondary H PER 2x 4 S. burkartii Ochoa S. irosinum Ochoa S. irosinum forma tarrosum Ochoa (1999) Solanum cajamarquense Ochoa Secondary H PER 2x (1EBN) 3 S. cajamarquense Ochoa Solanum candolleanum Berthault Primary L PER 2x (2EBN), 3x 4 S. candolleanum Berthault S. abancayense Ochoa S. achacachense Cárdenas S. ambosinum Ochoa S. ancoripae Ochoa (1999) S. antacochense Ochoa S. aymaraesense Ochoa S. bill-hookeri Ochoa S. bukasovii Juz. S. bukasovii var. Multidissectum (Hawkes) Ochoa (1992a) S. bukasovii forma multidissectum (Hawkes) Ochoa (1999) S. canasense Hawkes S. canasense var. xerophilum (Vargas) Hawkes S. chillonanum Ochoa (1989a) S. coelestispetalum Vargas S. hapalosum Ochoa S. huancavelicae Ochoa (1999) S. longiusculus Ochoa S. marinasense Vargas S. multidissectum Hawkes S. orophilum Correll S. ortegae Ochoa (1998) S. pampasense Hawkes S. puchupuchense Ochoa (1999) S. sarasarae Ochoa S. sawyeri Ochoa S. saxatile Ochoa (1992b), as ‘saxatilis’ S. sicuanum Hawkes (1990) S. sparsipilum subsp. calcense (Hawkes) Hawkes S. tapojense Ochoa S. tarapatanum Ochoa S. ×mollepujroense Cárdenas & Hawkes Solanum cantense Ochoa Secondary H PER 2x (2EBN) 3 S. cantense Ochoa Solanum cardiophyllum Lindl. Tertiary MEX 2x (1EBN), 3x 1 S. cardiophyllum Lindl. S. cardiophyllum subsp. lanceolatum (Berthault) Bitter 24 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Species name Taxon according to according to Genepool Priority levels Countries Ploidy level Nuclear Hawkes (1990) or Spooner et al . (2014) Clade subsequental authors Solanum chacoense Bitter Secondary M ARG, BOL, BRA, PAR, PER, URU 2x (2EBN), 3x 4 S. chacoense Bitter S. arnezii Cárdenas S. calvescens Bitter S. chacoense subsp. chacoense S. chacoense subsp. muelleri (Bitter) Hawkes S. tuberosum subsp. Yanacochense Ochoa (2001); (=S. yanacochense (Ochoa) Gorbatenko (2006)) S. yungasense Hawkes Solanum chilliasense Ochoa Secondary H ECU 2x (2EBN) 3 S. chilliasense Ochoa Solanum chiquidenum Ochoa Secondary M PER 2x (2EBN) 3 S. chiquidenum Ochoa S. ariduphilum Ochoa S. chiquidenum forma amazonense Ochoa (1994b) S. chiquidenum var. gracile Ochoa (1994b) S. chiquidenum var. robustum Ochoa (1994b) Solanum chomatophilum Bitter Secondary L ECU, PER 2x (2EBN) 3 S. chomatophilum Bitter S. chomatophilum forma sausianense Ochoa (1994b) S. chomatophilum var. subnivale Ochoa (1994b) S. huarochiriense Ochoa S. jalcae Ochoa S. pascoense Ochoa S. taulisense Ochoa Solanum clarum Correll Secondary H GUA, MEX 2x 1 S. clarum Correll Solanum colombianum Dunal Secondary L COL, ECU, PER, VEN 4x (2EBN) 3+4 S. colombianum Dunal S. cacetanum Ochoa S. calacalinum Ochoa S. jaenense Ochoa S. moscopanum Hawkes S. nemorosum Ochoa S. orocense Ochoa S. otites Dunal S. pamplonense L.E. López S. subpanduratum Ochoa S. paramoense Bitter S. sucubunense Ochoa Solanum commersonii Dunal Tertiary M ARG, BRA, URU 2x (1EBN), 3x S. commersonii Dunal Solanum contumazaense Ochoa Secondary H PER 2x (2EBN) 3 S. contumazaense Ochoa Solanum demissum Lindl. Secondary L GUA, MEX 6x (4EBN) Complex3 S. demissum Lindl. S. ×semidemissum Juz. Solanum ×doddsii Correll BOL 2x (2EBN) 4 S. ×doddsii Correll GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 25 Species name rding to according to Genepool Priority es Ploidy level Nuclear Taxon acco Spooner et al . (2014) levels Countri Clade Hawkes (1990) or subsequental authors Solanum dolichocremastrum Tertiary PER 2x (1EBN) 3 S. dolichocremastrum Bitter Bitter S. chavinense Correll S. huanuchense Ochoa Solanum ×edinense Berthault MEX 5x [4] S. ×edinense Berthault S. ×edinense subsp. Salamanii (Hawkes) Hawkes Solanum ehrenbergii (Bitter) Rydb. Tertiary MEX 2x (1EBN) 1 S. ehrenbergii (Bitter) Rydb. S. cardiophyllum subsp. ehrenbergii Bitter Solanum flahaultii Bitter Secondary M COL 4x 3+4 S. flahaultii Bitter S. neovalenzuelae L.E.López Solanum gandarillasii Cárdenas Secondary M BOL 2x (2EBN) 4 S. gandarillasii Cárdenas Solanum garcia-barrigae Ochoa Secondary H COL 4x 3+4 S. garcia-barrigae Ochoa S. donachui (Ochoa) Ochoa Solanum gracilifrons Bitter Secondary H PER 2x 4 S. gracilifrons Bitter Solanum guerreroense Correll Secondary MEX 6x (4EBN) [Complex3] S. guerreroense Correll Solanum hastiforme Correll Secondary H PER 2x (2EBN) 4 S. hastiforme Correll Solanum hintonii Correll Secondary H MEX 2x 1 S. hintonii Correll Solanum hjertingii Hawkes Secondary H MEX 4x (2EBN) 1+4 S. hjertingii Hawkes S. hjertingii var. physaloides (Correll) Hawkes S. leptosepalum Correll5 S. matehualae Hjert. & T.R. Tarn Solanum hougasii Correll Secondary H MEX 6x (4EBN) Complex3 S. hougasii Correll Solanum huancabambense Ochoa Secondary M PER 2x (2EBN) 3 S. huancabambense Ochoa Solanum humectophilum Ochoa Tertiary PER 2x (1EBN) 3 S. humectophilum Ochoa Solanum hypacrarthrum Bitter Tertiary PER 2x (1EBN) 3 S. hypacrarthrum Bitter S. guzmanguense Whalen & Sagást. Solanum immite Dunal Tertiary PER 2x (1EBN), 3x 3 S. immite Dunal S. yamobambense Ochoa Solanum incasicum Ochoa Secondary H PER 2x (2EBN) S. incasicum Ochoa Solanum infundibuliforme Phil. Primary M ARG, BOL 2x (2EBN) 4 S. infundibuliforme Phil. Solanum iopetalum (Bitter) Hawkes Secondary M MEX 6x (4EBN) 3+4 S. iopetalum (Bitter) Hawkes S. brachycarpum (Correll) Correll Solanum jamesii Torr. Tertiary MEX, USA 2x (1EBN) 1 S. jamesii Torr. Solanum kurtzianum Bitter & Wittm. Secondary L ARG 2x (2EBN) 4 S. kurtzianum Bitter & Wittm. S. ruiz-lealii Brücher 26 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Species name Taxon according to according to Genepool Priority levels Countries Ploidy level Nuclear Hawkes (1990) or Spooner et al . (2014) Clade subsequental authors Solanum laxissimum Bitter Secondary H PER 2x (2EBN) 4 S. laxissimum Bitter S. neovargasii Ochoa S. santolallae Vargas Solanum lesteri Hawkes & Hjert. Secondary M MEX 2x 1 S. lesteri Hawkes & Hjert. Solanum lignicaule Vargas Tertiary PER 2x (1EBN) 4 S. lignicaule Vargas Solanum limbaniense Ochoa Secondary H PER 2x (2EBN) 4 S. limbaniense Ochoa Solanum lobbianum Bitter Secondary H COL 4x (2EBN) 3+4 S. lobbianum Bitter Solanum longiconicum Bitter Secondary L CRI, PAN 4x 3+4 S. longiconicum Bitter Solanum maglia Schltdl. Secondary H ARG, CHL 2x, 3x S. maglia Schltdl. Solanum malmeanum Bitter Tertiary ARG, BRA, PAR, URU 2x (1EBN), 3x S. malmeanum Bitter Solanum medians Bitter Secondary M CHL, PER 2x (2EBN), 3x 4 S. medians Bitter S. arahuayum Ochoa (1994a) S. sandemanii Hawkes S. tacnaense Ochoa S. weberbaueri Bitter Solanum ×michoacanum (Bitter) Rydb. MEX 2x [1] S. ×michoacanum (Bitter) Rydb. Solanum microdontum Bitter Secondary L ARG, BOL 2x (2EBN), 3x 4 S. microdontum Bitter S. microdontum subsp. gigantophyllum (Bitter) Hawkes & Hjert. S. microdontum var. montepuncoense Ochoa Solanum minutifoliolum Correll Tertiary ECU 2x (1EBN) 3 S. minutifoliolum Correll Solanum mochiquense Ochoa Tertiary PER 2x (1EBN) 3 S. mochiquense Ochoa S. chancayense Ochoa S. incahuasinum Ochoa Solanum morelliforme Bitter & Muench Secondary M BOL, GUA, MEX, HON 2x 1 S. morelliforme Bitter & Muench Solanum multiinterruptum Bitter Secondary L PER 2x (2EBN), 3x 4 S. multiinterruptum Bitter S. chrysoflorum Ochoa S. moniliforme Correll S. multiinterruptum forma albiflorum Ochoa S. multiinterruptum forma longipilosum Correll S. multiinterruptum var. Machaytambinum Ochoa (1999b) Solanum neocardenasii Hawkes & Hjert. Secondary H BOL 2x S. neocardenasii Hawkes & Hjert. Solanum neorossii Hawkes & Hjert. Secondary L ARG 2x 4 S. neorossii Hawkes & Hjert. Solanum neovavilovii Ochoa Secondary H BOL 2x (2EBN) 4 S. neovavilovii Ochoa GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 27 Species name rding to according to Genepool Priority es Ploidy level Nuclear Taxon acco Spooner et al . (2014) levels Countri Clade Hawkes (1990) or subsequental authors Solanum ×neoweberbaueri PER 3x [4] S. ×neoweberbaueri Wittm. Wittm. Solanum nubicola Ochoa Secondary H PER 4x (2EBN) 4 S. nubicola Ochoa Solanum okadae Hawkes & Hjert. Primary M BOL 2x [4] S. okadae Hawkes & Hjert. Solanum olmosense Ochoa Secondary H ECU, PER 2x (2EBN) 3 S. olmosense Ochoa Solanum oxycarpum Schiede Secondary M MEX 4x (2EBN) 3+4 S. oxycarpum Schiede Solanum paucissectum Ochoa Secondary L PER 2x (2EBN) 3 S. paucissectum Ochoa Solanum pillahuatense Vargas Secondary H PER 2x (2EBN) 4 S. pillahuatense Vargas Solanum pinnatisectum Dunal Teriary MEX 2x (1EBN) 1 S. pinnatisectum Dunal Solanum piurae Bitter Secondary H PER 2x (2EBN) 3 S. piurae Bitter Solanum polyadenium Greenm. Secondary M MEX 2x 1 S. polyadenium Greenm. Solanum raphanifolium ium Cárdenas & Cárdenas & Hawkes Secondary L PER 2x (2EBN) 4 S. raphanifol Hawkes S. hawkesii Cárdenas Solanum raquialatum Ochoa Tertiary PER 2x (1EBN) 3 S. raquialatum Ochoa S. ingaefolium Ochoa Solanum ×rechei Hawkes & Hjert. ARG 2x, 3x [4] S. ×rechei Hawkes & Hjert. Solanum rhomboideilanceolatum Secondary H PER 2x (2EBN) 3 S. rhomboideilanceolatum Ochoa Ochoa Solanum salasianum Ochoa Secondary H PER 2x 4 S. salasianum Ochoa Solanum ×sambucinum Rydb. MEX 2x [1] S. ×sambucinum Rydb. Solanum scabrifolium Ochoa Tertiary PER 2x 3 S. scabrifolium Ochoa Solanum schenckii Bitter Secondary M MEX 6x (4EBN) Complex3 S. schenckii Bitter Solanum simplicissimum Ochoa Tertiary PER 2x (1EBN) 3 S. simplicissimum Ochoa (1989b) Solanum sogarandinum Ochoa Secondary M PER 2x (2EBN), 3x 4 S. sogarandinum Ochoa Solanum stenophyllidium Bitter Tertiary MEX 2x (1EBN) 1 S. stenophyllidium Bitter S. brachistotrichium (Bitter) Rydb. S. nayaritense (Bitter) Rydb. Solanum stipuloideum Rusby BOL 2x (1EBN) S. stipuloideum Rusby7 S. circaeifolium Bitter S. circaeifolium subsp. quimense Hawkes & Hjert. S. capsicibaccatum Cárdenas S. soestii Hawkes & Hjert. Solanum stoloniferum Schltdl. Secondary MEX, USA 4x (2EBN) Complex3 S. stoloniferum Schltdl. S. fendleri A. Gray S. fendleri subsp. arizonicum Hawkes 28 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Species name Taxon according to according to Genepool Priority levels Countries Ploidy level Nuclear Hawkes (1990) or Spooner et al . (2014) Clade subsequental authors S. papita Rydb. S. polytrichon Rydb. S. stoloniferum subsp. moreliae Hawkes Solanum tarnii Hawkes & Hjert. Tertiary M MEX 2x 1 S. tarnii Hawkes & Hjert. Solanum trifidum Correll Tertiary MEX 2x (1EBN) 1 S. trifidum Correll Solanum trinitense Ochoa Tertiary PER 2x (1EBN) 3 S. trinitense Ochoa Solanum ×vallis-mexici Juz. MEX 3x S. ×vallis-mexici Juz. Solanum venturii Hawkes & Hjert. Secondary H ARG 2x (2EBN) 4 S. venturii Hawkes & Hjert. Solanum vernei Bitter & Wittm. Primary L ARG 2x (2EBN) 4 S. vernei Bitter & Wittm. S. vernei subsp. ballsii (Hawkes) Hawkes & Hjert. Solanum verrucosum Schltdl. Secondary M MEX 2x (2EBN), 3x, 4x 4 S. verrucosum Schltdl. S. macropilosum Correll Solanum violaceimarmoratum Secondary H BOL, PER 2x (2EBN) 4 S. violaceimarmoratum Bitter Bitter S. multiflorum Vargas S. neovavilovii Ochoa S. urubambae Juz. S. villuspetalum Vargas Solanum wittmackii Bitter Tertiary PER 2x (1EBN) [3] S. wittmackii Bitter Solanum woodsonii Correll PAN 4x 4 S. woodsonii Correll Solanum tuberosum L. CHL (Chilean Chilotanum group landraces) 4x (4EBN) 4 S. tuberosum subsp. tuberosum Landraces from Solanum tuberosum W Venezuela 2x (2EBN), 3x, Andigenum group South to N 4x (4EBN) 4 S. chaucha Juz. & Bukasov Argentina S. phureja Juz. & Bukasov S. phureja subsp. estradae (L. López) Hawkes S. phureja subsp. hygrothermicum (Ochoa) Hawkes S. stenotomum Juz. & Bukasov S. stenotomum Juz. & Bukasov subsp. goniocalyx (Juz. & Bukasov) Hawkes S. tuberosum subsp. andigenum Hawkes Solanum ajanhuiri Juz. & Bukasov BOL, PER 2x (2EBN) 4 S. ajanhuiri Juz. & Bukasov Solanum curtilobum Juz. & Bukasov BOL, PER 5x 4 S. curtilobum Juz. & Bukasov Solanum juzepczukii Bukasov ARG, BOL, PER 3x 4 S. juzepczukii Juz. Species in brackets have not yet investigated, relationships were proposed by Spooner et al. (2014) based on morphological similarity; Complex3 and 4 indicate the complex multi-clade hybrid origins of these species. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 29 4 POTATO PRODUCTION AND DIVERSITY After wheat and rice, cultivated potato is the third The highest potato production can be found in Asia most important food crop for human consumption with 189.9 million t on 9.3 million ha, followed by (FAOSTAT, 2021b) and source of primary income for Europe with 107.3 million t on 4.7 million ha, America many societies around the world. It is primarily grown with 45.1 million t on 1.54 million ha and Africa with for direct consumption markets but also provides raw 26.5 million t on 1.76 million ha (Figure 4.1.1 a). material for processed products such as frozen chips, Countries with the highest production are China (91.8 crisps, preserved potatoes and starch (EUROSTAT, 2021). million t), India (50.2 million t), Russia (22.1 million t), Ukraine (20.3 million t), USA (19.2) and Germany 4 .1 Economic importance (10.6 million t) (FAOSTAT, 2021b). Although Eastern Africa, South America and Eastern Europe cultivate Potato is the world’s most important non-cereal potatoes on a wider area, production is more inten- food crop, with a global production of 370 million sive in Northern Africa, America and Western Europe tonnes (FAOSTAT, 2021b) (Annex 2, Annex Table 2.1). and therefore production volumes are higher (Figure Most varieties grown (approximately 99%) belong to 4.1.1 b) (FAOSTAT, 2021b). However, a large increase S. tuberosum ssp. tuberosum and are produced for in area has been registered over the last 20 years in local markets as tubers, with their limited storability African countries, and in 2005 the production volume restricting global distribution (Haverkort and Struik, of developing countries, including India and China, 2015). However, Haverkort and Struik (2015) reported exceeded for the first time the developed world, that companies in the Netherlands export 600,000 to indicating that the importance of the potato for diets, 800,000 t of seed potato annually to Cuba and Bangla- employment and income is increasing in Asia, Africa desh. and Latin America (Devaux et al., 2020). 30 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Potatoes in market, Huncayo, Peru. Photo: Michael Major/Crop Trust In the last 60 years, potato production volume strong political promotion. This support led to eco- increased by 37% (Figure 4.1.1 d), and yield also nomic growth and welfare over the last two centu- increased significantly (+75%, Figure 4.1.1 c). On ries and potato became even a staple inferior good average, the global potato yield was 21.4 t ha-1 and (i.e. its demand decreases when consumer income achieved the highest values in Kuwait (50.6 t ha−1), increases). However, rising income stimulates diversi- USA (50.3 t ha−1), New Zealand (49.8 t ha−1) and Den- fication of food consumption (Salmensuu, 2021). The mark (42.5 t ha−1). The highest yields were most likely shift towards cereals in animal feeding and trends for achieved by large commercial farms using all available low-calorie diets and to spend less time in cooking led inputs optimally in 2019 (FAOSTAT, 2021b). In rainfed to reductions in the amount of potato consumed in agriculture, potatoes have some important advan- developed countries (EUROSTAT, 2021). By contrast, in tages over cereals due to their harvest index (ratio developing countries, the level of use is still relatively of harvested product to total biomass) of 0.75–0.95 low. Here, potato is slowly establishing as a staple (Haverkort and Struik, 2015) compared to cereals of food and, therefore, the price levels are still higher about 0.4–0.6 (Hay, 1995). In addition, potato pro- (Salmensuu, 2021). However, promoting policies, such duces 5,600 kcal per m³ of water, which is +45%, as those conducted in China (Liu et al., 2021), could +243% and +280% higher compared to maize, wheat stimulate sustainable potato farming systems and the and rice, respectively (Monneveux et al., 2013). Potato economy and welfare of the country. is also cultivated at high elevation and poorer soils and contributes substantially to the daily intake of Cultivated potato is produced for different types of energy and nutrients, especially in remote areas (Scott, markets. These include specific table varieties used at 2011). Therefore, as a locally traded product, potato is home and in restaurants which show specific skin type essential for regional food security and poverty reduc- and flesh and skin coloration. The French-fry industry tion (George et al., 2017). asks for elongated tubers with long dormancy. The chip-processing industry is interested in a high starch Potato use and economic importance differ across content and low accumulation of reducing sugar at regions. In Europe, potato was initially a luxury good 10°C storage to avoid Maillard reactions and browning and yet developed into a crop for the poor due to (Hirsch et al., 2013). As the ‘Petota’ group is very (a) Africa America Asia Europe 1.76 Mio 1.54 Mio 9.30 Mio 4.70 Mio * ² ern * SSoouutthheerrnn EEaassteterrnn North S rn outhern Northern E E a as Southe Ce t n s e t t r r e n a r l n * (b) 26.5 Mio 45.1 Mio 189.8 Mio 107.3 Mio **² Sou W t n e h s e t r ste r e n Ea Sout r hern n No Southern M rth id er E d n le a E s a t s e t r e n rn * * * Caribbean *Southeastern *²Western *Southern (c) M. Nagel (2022) 19.7 21.4 370.4 368.0 -1 Global yield in t ha 15.7 14.2 14.4 13.7 12.2 305.5 (d) 270.5 279.5 267.8 257.0 Global produc on in million tonnes 1961 1971 1981 1991 2001 2011 2019 Figure 4 .1 .1 . Global potato production and area harvested. (a) Area harvested and (b) production volume shown for different regions on five continents in 2019. Development of (c) yield and (d) global potato production over the last 60 years. Source: FAOSTAT, 2021b, *as explained in the figure. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 31 Producon (tonnes) Area harvested (ha) N N o o r r t t h he e rn rn Central Cent C r e a nt l ral Northern 1.7 Mio t --- Oceania --- 0.40 Mio ha rn West e ddleMi rn rnn Wes te es ttere Wes W diverse, potato genetic resources can have a valuable wirtschaft, Bundessortenamt und CHemische Industrie impact on these industries. However, in order to assess (BBCH) scale (Figure 4.2.1). these genetic resources, they need to be compre- hensively described, evaluated and integrated into For optimum growth (George et al., 2017), most breeding programs. potatoes require a minimum temperature of 6°C for sprouting and show optimal tuber development in a 4 .2 Potato development, descriptors range between 18–20°C, a soil temperature between and potato diversity 15- 18°C and a water potential of -25 kPa. Intense drought stress impairs cellular functions and occurs Potatoes are herbaceous perennial plants grown in when water potential is at or below – 0.8 MPa. Higher different temperate climates. Potato growth and soil temperatures in combination with elevated air developmental stages can be divided into four major temperatures can also cause severe stress. At tem- phases (Figure 4.2.1) a) the vegetative growth with peratures above 38°C, photosystem II is irreversibly the development of shoots and leaves; b) tuber initi- destroyed. ation with the emergence of tubers at the end of the stolons; c) the growth of tubers and their significant Depending on the climatic conditions in the areas of increase in size; and d) final maturation, when the cultivation, production has been adapted to the most leaves senesce and tuber skin thickens. Depending on appropriate season. Thereby, Haverkort and Struik the environmental conditions, the genotype used, and (2015) identified six cropping systems: hence the specific production system (see below), the developmental period can last between 90–180 days Rainy summer: production occurs during the frost-free and can be divided into specific stages according to period under rain-fed conditions, occasionally irriga- the Biologische Bundesanstalt für Land- und Forst- tion is used. Long growing seasons (180 days) and long Vegeta ve growth Tuber ini a on Tuber growth Matura on Leaf Sproung Forma on of Stem Tuber Pre- Flowering Development development side shoots elonga on Senescence forma on flowering of fruit BBCH 01-09 10-19 20-39 40 50 51-59 61-69 71-90 91-97 205-40 Growth (days) 20-25 15-25 40-60 15-25 Descriptors Sprout and stem characters Tuber characters* Leaf characters Flower and fruit characters Growth habit Agronomic traits: Weeks to flowering; weeks to tuber dormancy; weeks to harvest, tuber yield components Environmental adaptability: Reac on to frost; reac on to drought; reac on to high temperatures Disease and pest reac ons: Reac ons to fungi; bacteria; viruses, viroids, mycoplasma; nematodes Figure 4 .2 .1 . Stages of potato development and applied descriptors to characterise and evaluate potato genetic resources. Data on growth stages are based on Nemes et al. (2008) and descriptors are based on Huaman et al. (1977). * Tubers are characterized on basis of their morphology [color, shape, skin, flesh) and can be evaluated on basis of their biochemical traits (dry matter content, total nitrogen content, relative nutritive value, total glycoalkaloids (TGA)]. 32 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO M. Nagel 2022 day-lengths lead to high yields, e.g. in Europe and In order to identify and describe potato genetic South Africa’s High Veld. resources suitable for the different production systems and climatic conditions, a descriptor list for potato Dryland summer: high solar radiation in combination was developed at the planning conference of on with optimum irrigation achieve highest potato yields; “Utilization of the genetic resources of the potato in the north western United States and Kuwait. II” held at CIP in October 1977 (Huaman et al., 1977). The descriptors involve a list of relevant passport Partly irrigated spring: potatoes grow over winter information, data on germplasm collections and (110 days) and are harvested in spring, e.g. in Medi- morphological traits to be phenotyped during and terranean climates, North Africa, South America and after the growing season. In addition, to describe the South Africa. detailed characteristics of potato varieties, a form has been developed by the International Union for Irrigated autumn: after the hot summers, potatoes are the Protection of New Varieties of Plants (UPOV). cultivated over autumn (100 days) and are harvested Comparable to the descriptor list for potato genetic before winter, yields are usually low due to low solar resources (Huaman et al., 1977), the UPOV list (UPOV, radiation; e.g. in Mediterranean climates. 2004) includes sprout, stem, tuber, leaf, flower, fruit, plant type and growth habit characters (Figure 4.2.1). Irrigated winter: cultivation after the rainy summer Furthermore, disease and pest resistances are often (90–100 days) during the heat-free period; found in evaluated using standardized tests, or responses to areas with monsoon climate. other abiotic and biotic stresses are documented through additional experimental setups. However, Equatorial highlands: production under rain-fed con- most potato collections have chosen to use their own ditions in two main growing seasons (100 days each); specific list of descriptors. Examples of described traits above 1,800 m in East and Central Africa. at the different stages of development are provided Figure 4.2.2 to 4.2.5). GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 33 GLKS 10152 GLKS 10035 GLKS 11289 GLKS 11726 ‘Allagash Russet‘ ‘King Edward‘ ‘Barbara‘ ‘Pentland Beauty‘ USA UK Germany UK GLKS 12308 GLKS 12035 GLKS 12283 GLKS 12319 ‘Highland Burgundy Red‘ ‘Purple and White‘ ‘Schwarze Ungarin‘ ‘Blaue Fankhaus‘ UK USA Hungaria Switzerland GLKS 12317 GLKS 26177 GLKS 26305 ‘Vitelotte‘ ‘Puka Quitish‘ ‘Yana Sucre‘ France Peru Peru Tuber characters • Predominant tuber skin color • Unusual tuber shape • Secondary tuber skin color • Depth of tuber eyes • Distribution of secondary tuber color • Note of eyes per tuber • Tuber skin type • Distribution of tuber eyes • General tube shape • Predominant sprout color Figure 4 .2 .2 . Cultivated potatoes differing in tuber skin color, type, shape and tuber eye distribution (Photos: Klaus J. Dehmer; Photo arrangement: Manuela Nagel, IPK, 2022). 34 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Photos K. J. Dehmer/ Arrangement M. Nagel 2022 GLKS 11605 GLKS 11525 GLKS 10033 GLKS 11432 ‘Long Blue‘ ‘Jaeria‘ ‘Ulster Prince‘ ‘Eta‘ Cuba The Netherlands UK Slovakia GLKS 26177 GLKS 26305 GLKS 12344 GLKS 12151 ‘Puka Quitish‘ ‘Yana Sucre‘ ‘UACH 0061‘ ‘Kefermarkter Zuchtstamm‘ Peru Peru Chile Austria GLKS 12308 GLKS 12196 GLKS 12202 GLKS 12317 GLKS 12186 ‘Highland Burgundy Red‘ ‘Rheinische Rote‘ ‘Salad Blue‘ ‘Vitelotte‘ ‘Königsblau’ UK Germany France Germany Tuber flesh characters • Predominant tuber flesh color • Secondary tuber flesh color • Distribution of secondary tuber flesh color Figure 4 .2 .3 . Cultivated potatoes differing in tuber flesh color and distribution of flesh color (Photos: Klaus J. Dehmer; Photo arrangement: Manuela Nagel, IPK, 2022). GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 35 Photos K. J. Dehmer/ Arrangement M. Nagel 2022 GLKS 30849 GLKS 32869 GLKS 32347 GLKS 30529 S. microdontum S. circaeifolium S. trifidum S. stoloniferum Argentinia Bolivia Mexico Mexico GLKS 30010 GLKS 30393 GLKS 31703 S. acaule S. demissum S. infundibuliforme Bolivia Colombia Argentina GLKS 35375 GLKS 30973 GLKS 32207 S. polyadenium S. sparsipilum S. bukasovii Mexico Bolivia Peru Leaf characters Sprout and stem characters Growth habit • Leaf dissection • Secondary sprout color • Growth habit type • Abaxial leaf pubescence • Distribution of • Branching habit • Adaxial leaf pubescence secondary sprout color • Number of the primary stem • Type of hairs (trichomes) • Stem color • Plant height at flowering stage • Stem cross section • Stem wing Figure 4 .2 .4 . Wild potatoes differing in leaf dissection, pubescence and type of hair on the leaf surfaces (Photos: Klaus J. Dehmer; Photo arrangement: Manuela Nagel, IPK, 2022). 36 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Photos K. J. Dehmer/ Arrangement M. Nagel 2022 GLKS 11289 GLKS 31815 GLKS 11488 S. tuberosum ‘Barbara‘ S. stoloniferum S. tuberosum ‘Heideniere‘ Germany Mexico Germany GLKS 31772 GLKS 11382 GLKS 31767 S. bulbocastanum S. tuberosum ‘Dobra‘ S. bulbocastanum Mexico Germany Mexico GLKS 12184 GLKS 11804 GLKS 31920 S. tuberosum ‘Kipfler Braun‘ S. tuberosum ‘Rosabelle‘ S. acaule Germany France Argentina GLKS 10985 GLKS 26437 S. tuberosum ‘Cardinal‘ S. stenotomum ‘Pishgosh‘ The Netherlands Peru Flower and fruit character • Calyx color and symmetry • Pistil pigments • Pedicel articulation position • Corolla shape • Pistil morphology • Pigment at pedicel articulation • Predominant flower color • Style length • Self-compatibility • Secondary flower color • Stigma shape • Fruit shape • Distribution of secondary • Degree of flowering • Fruit color flower color • Premature flower abscission • Number of fruits • Anther pigments • Duration of flowering • Seed set • Stamen formation • Number of flowers per • Seed pigment • Pollen production inflorescence Figure 4 .2 .5 . Cultivated and wild potatoes differing in flower and fruit characters (Photos: Klaus J. Dehmer; Photo arrangement: Manuela Nagel, IPK, 2022). GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 37 Photos K. J. Dehmer/ Arrangement M. Nagel 2022 5 IN SITU CONSERVATION OF NATIVE POTATO VARIETIES Traditional landraces of potato have been cultivated 5 .1 Threats to native potato diversity in South America for millennia and are still grown by smallholder farmers between western Venezuela Potato landraces and northern Argentina and along the coast of Chile (De Haan and Rodriguez, 2016). Most landraces are Indigenous farmers, in particular in Argentina, Bolivia, cultivated in the Andes (Cadima et al., 2014). Farmers, Chile, Ecuador and Peru, grow more than 3,000 native their families and communities aim to preserve these potato varieties in South America (Spooner et al., valuable food resources in combination with tradi- 2014), many of which are threatened by various recent tional cultivation practices, uses, cultural traditions developments. In northern Argentina, the number of and beliefs (Scott, 2011; Lüttringhaus et al., 2021). local varieties grown is declining in some areas, due The wild relatives of S. tuberosum are restricted to an to: (i) displacement by other crops, (ii) threats from area between the southwestern United States and the pests and diseases, (iii) low accessibility of clean virus- southern end of South America (Spooner et al., 2014). free material of local varieties, and (iv) the migration The local landraces and the wild species occurring of the farmers and their families towards urban cen- across their natural range represent a huge reservoir ters (Ispizúa et al., 2007). In Ecuador, local landraces of genetic and morphological diversity important for of potato are threatened with extinction because potato breeding, for the adaptation to environmental traditional varieties are being replaced by new high- changes and for resistance to pest and diseases. The yielding varieties, more pest and disease pressure and conservation of the genetic resources of native potato the lack of market opportunities (Unda et al., 2005). germplasm in situ and on farm is critically important In Chile, indigenous and peasant communities grew to sustain the productivity of this major global crop. between 800 to 1,000 native potato varieties; nowa- 38 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO , Field work of Aguapan farmers in the Andean highlands at 3,500 m. Photo: Manuela Nagel/IPK days, only 270 local varieties are cultivated according Wild potato species to the Austral University of Chile. In Peru, a total of 42 landraces were identified in the communities Haquira At the global level, 26 wild potato species have been – Pauchi, Queuñapampa and Huancacalla Chico, of assessed by the International Union for Conservation which 13 were considered as threatened, eight were of Nature (IUCN) Red List, of which 19 are considered conservation-dependent and three were not at risk of as priority potato crop wild relatives (Vincent et al., loss. Among the reasons for this, many young farmers 2013). Among the assessed species, 16 are classified as abandon agriculture and search for attractive options Least Concern (61.5%), four as Endangered (15.4%), with higher income (Valdivia-Díaz et al., 2015). How- two as Near Threatened (7.7%), two as Vulnerable ever, local traditions and customs have maintained the (7.7%) and two as Data Deficient (7.7%) (Table local diversity of potato landraces relatively well, and 5.1.2.1). In Argentina, seven endemic wild potato heavy declines as seen for other crops have not been species were assessed according to the IUCN Red List observed yet (De Haan and Rodriguez, 2016). and S. xbrucheri was classified as Near Threatened, S. xrechei as Vulnerable and the remaining five as of The diversity of potato resources is also severely Least Concern (Palchetti et al., 2020). threatened by the effects of climate change, including increases in temperature, change in spatial and In Bolivia, the assessment of the vulnerability of the temporal patterns of precipitation and phenomena 21 endemic potato wild relatives (Cadima et al., 2014) associated with El Niño. Hijmans (2003) assessed the revealed that five endemic potato species (24%) are impact of climate change on global potato production classified as Critically Endangered, four as Endangered and predicted that between 1961–1999 and 2040– (19%), six as Vulnerable (28%) and the remaining 2069, global potato yield potential could decrease by six as either Near Threatened or of Least Concern 18% (without adaptation), especially in lower latitude (28%). Human access, fire and livestock pressure were areas. Some of the risks to the production of rain-fed reported as the main threats, substantially impacting potato crop in Peru include climatic disasters, e.g. all the species. The most threatened species were the El Niño drought in the southern highland in 1983 S. achacachense (EN), S. arnezii (VU), S. brevicaule and severe flooding near Cusco in 2010 (Scott, 2011). (LC), S. flavoviridens (CR), S. hoopesii (EN), Solanum Furthermore, the potato wild relatives are under enor- ugentii Hawkes & K.A. Okada (EN) and S. sucrense mous pressure from habitat loss and environmental (NT). Four of these seven species were spotted in only degradation, as a result of climate change, which a few areas. Therefore, Cadima et al. (2014) identi- makes habitats unsuitable for these species and could fied sites of approximately 50 km2 to conserve all 21 cause their extinction. About 16–22% of wild popu- endemic wild potato relatives of Bolivia, including S. lations of potato species are predicted to go extinct, achacachense (EN) in La Paz and the endangered S. with possibly losing 50% of their range size by 2055 hoopesii and S. ugentii in Chuquisaca. (Jarvis et al., 2008). Table 5 .1 .2 .1. The IUCN Red List categories of priority Solanum section Petota crop wild relatives (https://www.iucnredlist.org/, accessed on 21st April 2020). Priority Solanum crop wild relatives according to Vincent et al. (2013) are indicated by **. LC, least concern species; EN, endangered species; NT, near threatened; VU, vulnerable species; DD, data deficient. Scientific name IUCN status Scientific name IUCN status Solanum agrimonifolium** LC Solanum jamesii LC Solanum albornozii ** EN Solanum lesteri** DD Solanum bulbocastanum** LC Solanum minutifoliolum LC Solanum cardiophyllum LC Solanum morelliforme** LC Solanum chilliasense** VU Solanum oxycarpum** EN Solanum clarum** VU Solanum pinnatisectum LC Solanum demissum** LC Solanum polyadenium** LC Solanum ehrenbergii LC Solanum schenckii** EN Solanum guerreroense** DD Solanum stenophyllidium LC Solanum hintonii** NT Solanum stoloniferum** LC Solanum hjertingii** LC Solanum tarnii** EN Solanum hougasii** LC Solanum trifidum NT Solanum iopetalum** LC Solanum verrucosum** LC GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 39 5 .2 In situ conservation projects in Latin The project participants have also established micro- America gene centers of biodiversity of Andean tubers and maintain an inventory of 11 priority crops, among Peru them potato, in 472 conservationist farms involving 154 communities from 53 districts in 12 regions. Peru has the largest number of landraces and wild species of potato. Following the classification of The ‘Potato Park’ (Parque de la Papa), a well-known Hawkes (1990), seven domesticated species with 3,000 project supported by the International Treaty (FAO, landraces/native varieties and 91 wild species are 2009a), conserves native potato diversity in combina- native to Peru. Since 1990, the conservation of native tion with its cultural landscape, including its agro- potatoes in Peru has been supported by a series of in biodiversity, wild relatives and associated knowledge situ conservation projects. Non-governmental organi- (see also chapter 5.3.2). The Potato Park comprises a zation (NGO) groups, scientists and research organi- high elevation valley of an area of 15,000 ha outside zations (Scott, 2011) work closely with farmers on in Cusco, Peru and is organized by five different farming situ conservation of native potato varieties. In par- communities. The communities maintain their own ticular, NGOs provide technical assistance, training in genebank to foster diversity awareness and exchange conservation approaches, support exchange of native of landraces. varieties and create community-based diversity repos- itories. They also help repatriate varieties collected The International Potato Center (CIP, PER00) in Lima in local communities and support the development has also provided significant support for in situ conser- of new/improved products from indigenous potato vation of landraces since 1998 (Scott, 2011) and works varieties. The NGO Centro IDEAS in Cajamarca, for with farmers in the Cusco region and other highland example, supports local farmers in the in situ conser- regions known to have high diversity of native pota- vation of over 130 varieties. They register and utilize toes, including the Potato Park. CIP provides clean local native potatoes and document traditional culti- virus-free native varieties, information and support to vation approaches and local knowledge (Scott, 2011). improve potato cultivation. Over 9,400 high quality Within the local communities, there are some farmers, samples of more than 1,300 native potatoes have been also known as stewards or “conservacionistas” or repatriated to more than 94 Andean farm communi- “cuidadores” of biodiversity who pursue many of the ties in 12 regions of Peru during this period (Gomez et traditional conservation practices. Further studies al., 2018; Lüttringhaus et al., 2021). and inventories of plant genetic resources including potato local varieties have also been carried out in CIP has been actively documenting the diversity of the regions of Cusco, Huánuco, San Martín, Apurímac, native potato landraces in key hotspots in Peru as part Piura, Arequipa, Cajamarca, Lima, Puno, Loreto and of the CGIAR research program on Roots, Tubers and Ucayali (Gallardo et al., 2009). Bananas (CRP-RTB). The program aims to promote an integrated and complementary approach to the The most important in situ project, implemented by conservation and the use of the genetic diversity of the Instituto Nacional de Innovación Agraria (INIA), five priority crops, including potato. A detailed study the Peruvian Amazon Research Institute (IIAP), and the on the diversity of potato landraces in the Bolivian NGOs ARARIWA Association, Agrarian Services Center, Altiplano and in Peru (Apurimac and Huancavelica) as Proyecto of Campesino Technological Alternatives well as in Pasco department was carried out. In par- and Coordinator of Andean Science and Technology, ticular, the Pasco department has a great geograph- is the UNDP/GEF funded project “In Situ Conservation ical and ecological diversity ranging from altitudes Project for Native Crops and their Wild Relatives”. It of 5,723 m down to the Amazon basin. Overall, nine ran between 2001–2006 and supported the national communities participated in the Pasco region. In each in situ conservation of several crops, including pota- of the communities, so-called guardians maintain in toes. The project has contributed to conserving plant situ between 49–81 different landraces/native varieties genetic resources as an important natural heritage by representing 3–5 different potato species. Following • preserving agrobiodiversity in farmers’ fields, legal procedures and with the agreement of the indig- • protecting wild relatives, enous communities, CIP managed to introduce 544 • strengthening peasant organizations, accessions into the international potato genebank. • raising awareness about the ecological, cultural and nutritional value of crops, Another CRP-RTB project led by CIP established a • developing policies to support in situ conservation, hotspot-based in situ network called ‘Chiripaq Nan • developing and consolidating markets, and network’ for a systematic monitoring of potato land- • developing an information and monitoring system, races (De Haan and Rodriguez, 2016). This involved as a tool for planning and coordinating agrobiodi- the identification of landrace diversity hotspots within versity conservation activities in Peru. the native potato center of diversity in Argentina 40 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO (Jujuy Province), Bolivia (Department of La Paz), Chile knowledge about the crop wild relatives of 16 genera (Chiloe Province), Colombia (Department of Nariño, of food crops, including potato. Furthermore, capac- Cauca Province), Ecuador (Chimborazo) and Peru ities and a national information system on crop wild (Departments of Cusco, Apurimac, Huancavellica and relatives was developed that integrates the informa- Huacanuco). The project documented total, relative tion dispersed among national institutions and man- and spatial diversity and collective knowledge. ages information for spatial analysis. Bolivia Ecuador Bolivia is a country rich in traditions and cultures In Ecuador, 23 wild species, and 3 cultivated species, with in situ conservation and on farm management S. phureja, S. chaucha and S. tuberosum subsp. andi- practices dependent on the indigenous knowledge gena (Monteros-Altamirano, 2011), including more of its people (Bolivia, 2009). Within the framework than 400 landraces of native potatoes, have been of the National System of Genetic Resources for Food reported (Unda et al., 2005; Monteros-Altamirano, and Agriculture (SINARGEAA), a complete inventory 2018). The number of landraces grown for subsistence of potatoes, oca, papalisa and isaño was carried purposes is hardly known but perhaps only 5% is out in 2002, in the Candelaria microcenter of the offered in markets (Unda et al., 2005). Two improved municipality of Colomi, department of Cochabamba varieties (INIAP ‘Gabriela’ and ‘Superchola’) occupy (Bolivia, 2009). In the North Potosí-Oruro microcenter, more than half of the cultivation area (Andrade et an inventory of native potatoes was made in eight al., 2002). To study the dynamics of potato cultivation communities of the Ayllus Chullpa, Aymaya, Thaya- in the provinces of Carchi, Chimborazo and Loja, the quira and Sullka region. These registers constitute potato diversity was compared between the 1970s, varietal records or censuses containing information the 1980s and 2006–2008 (Monteros-Altamirano, on the local names of the varieties, their distribution, 2011; Monteros-Altamirano, 2018). Potato farmers frequency, and abundance. Inventories have also been were interviewed and new landraces and names were made in other micro-centers around Lake Titicaca, discovered indicating change of the contemporary such as Titijoni (Ingavi province), Cachilaya (Los Andes system. However, potato farmers highly appreciate province) and Cariquina Grande (Camacho province). current developments of diversity fairs and re-intro- duction of landraces to maintain cultural heritage. PROINPA in Bolivia has also been active in imple- menting in situ conservation activities in microcenters Argentina, Chile, Brazil of diversity detected in the Andean zone and covering the entire value chain from agricultural production, In Argentina, much efforts have been expended to transformation and marketing. For example, in situ towards the on farm conservation of plant genetic conservation of the genetic diversity of native tubers resources, which include important crops for subsis- in Candelaria, Cantón of Colomi, in the Department of tence agriculture such as potato (Argentina, 2008). Cochabamba is supported by the Belgian Government In Puna and Prepuna, organizations such as Instituto and executed by PROINPA, the Catholic University Nacional de Tecnología Agropecuaria (INTA), Univer- of Louvain la Nueva and Gembloux of Belgium, the sidad Nacional de Mar del Plata (UNMdP), National Bolivian Private University, the municipality of Colomi, University of Jujuy (UNJu) and Universidad Nacional AIDAA, the Association of Andean Tubers Producers de Salta and different NGOs work collaboratively for of Colomi (APROTAC) and other organizations. The the in situ conservation of local potato varieties and results have been published in a book on the ‘Pro- their traditional knowledge, with a particular focus motion of the Diversity of Andean Tubers and their on culinary properties in combination with traditional Products Transformed’ (Bolivia, 2009). and new recipes. The different organizations support also the fairs of different communities that take place The Bolivian Ministry of Environment and Water, Vice once a month. Here, local farmers interchange crops Ministry of the Environment, Biodiversity and Climate and seeds for their own consumption and cultivation. Change (MMAyA-VMABCC) has undertaken different Obtaining healthy seeds continues to be a problem, actions related to research and conservation of crop but INTA recently set up a laboratory for the pro- wild relatives as a partner in the UNEP/GEF Global duction of healthy seed potatoes in the Abra Pampa Project “In Situ Conservation of the Wild Relatives station (personal communication Ariana Digilio, of Crops through the Strengthening of Information Argentina, 2022). Management and its Application in the Field” during the period 2005–2009 (Hunter and Heywood, 2011). Chile is considered a center of origin of the cultivated As an outcome, a Red Book of the crop wild rela- potato and has important traditional varieties (Seguel tives of Bolivia was published (Mora et al., 2009) that and Agüero, 2008). In five Chilean regions, civil society prioritized research work and generated considerable organizations support the rescue of local seeds and GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 41 indigenous knowledge. The organizations promoted promote the conservation and use of the vast diversity the concept of women guardians of local traditions of native potatoes from central Peru. Each AGUAPAN to save, cultivate and exchange the seeds of ancient member cultivates between 50–300 varieties of native varieties. There have also been national initiatives for potatoes through sustainable management practices. the rescue, protection, sanitation and commercializa- This includes planting in chaqru or wachuy (variety tion, of value chains for the native potato varieties mixtures) and uses technologies such as the chakita- of Chiloé, executed by the Austral University of Chile klla plow that allows direct sowing, thus reducing soil with financial support of the Foundation for Agrarian erosion. AGUAPAN also promotes cooperation and Innovation (FIA) and participation of many local public solidarity among its associates, as well as the exchange and private partners. Furthermore, INIA (CHL071) of seeds, knowledge and experiences. has promoted the production of certified native seed potatoes from Chile through the delivery of healthy, AGUAPAN is guided by five key principles: (1) Open- pathogen-free tubers to custodian farmers interested ness: Members of the association are those farmers in commercial seed production. who keep more than 50 varieties of native potato for more than two generations (father-son, moth- In Brazil, Heiden et al. (2017) have made a taxo- er-daughter) and are recognized by their community; nomic revision of the wild species of potato to map (2) Direct Deal: Dialogue and investment between the geographic distribution of herbaria samples and farmers and companies to share benefits without genebank accessions, and to identify gaps in ex situ transaction costs; (3) Self-determination: They are collections. A total of 655 distribution data points their own custodians, who know the needs and what were collected for the native potato species in Brazil. benefits they require; (4) Trust and Transparency: The The accessions of potato and their wild relatives main- information has to be shared among all partners; (5) tained at the Embrapa Clima Temperado genebank Good Governance: The elected managers have clear were evaluated for their morphological and agronom- responsibilities, promote gender equity and continu- ical characteristics. Their analysis showed that there ally improve management. are more taxa native to the country than previously recognized. The ‘guardian’ farmers live in geographically isolated communities and are not familiar with the interna- 5 .3 Complementarity with ex situ con- tional treaties which are in place to protect farmers’ servation rights. AGUAPAN helps to raise awareness and knowl- edge of these custodian farmers on the role they play For successful conservation of all wild relatives of potato across their distribution range, it is important that in situ activities are complemented by ex situ con- servation, as some of the endemic and rare crop wild relatives face serious threats that could imminently drive them to extinction. Threatened sites and species should be prioritized for collecting missions to retrieve germplasm accessions to be preserved in genebanks. AGUAPAN guardians in Peru The Association of Guardians of the Native Potato of Central Peru (AGUAPAN), founded in Huancayo in 2014, is a self-organized association of potato farmers that strives to raise the wellbeing of their members while conserving this biodiversity (Naranjo, 2019). The farmers are known as ‘guardians’ and are passionate and show special interest in maintaining a collection of unique varieties, inherited from their families. However, they live in conditions of poverty, with limited access to health, education and value markets. AGUAPAN tries to raise support from the pri- vate sector and others and share benefits to improve farmers’ living conditions. The association initially grouped 50 families from equal numbers of com- munities from five regions of Peru (Huánuco, Junín, Figure 5 .3 .1 .1. AGUAPAN Guardians maintain unique native Pasco, Huancavelica and Lima), who partnered to potato varieties in Peru. (Photo: Stephany Naranjo, 2019) 42 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO in conserving biodiversity for the whole of humanity joint effort between an ex situ genebank and the and helps to find ways to improve their living condi- native farmers who protect and maintain the culture tions while conserving biodiversity. and diversity in situ, the harmony of closing the gap between ex situ and in situ conservation is brought AGUAPAN has been financially supported by a Dutch closer, with an enhanced understanding of the value potato seed company (HZPC) and a Dutch coopera- to both (personal communication David Ellis, 2022). tive (AGRICO) dedicated to potato breeding and seed production. The main investment has gone to sup- In situ conservation of wild potato germplasm port each farmer in the education of their children, in Argentina agricultural inputs or family health. The rest of the funds are invested in paying for the annual assembly To determine and prioritize specific sites as genetic of AGUAPAN, a health fund to support farmers who reserves in Argentina, a literature search was com- need medical attention and the quarterly sessions of bined together with field-based research (Marfil et al., the board of directors. 2015). S. kurtzianum was used as an example of a wild relative of potato in a protected nature reserve to Parque de la Papa in Peru devise a protocol for active monitoring of the popu- lations in selected sites to ensure long-term conser- The Parque de la Papa (Potato Park) was created vation. Further, Garavano (2018) investigated in situ in 1998 as a bio-cultural territory focused not only conservation to protect S. commersonii in the Paititi on the conservation of native potatoes but also on Private Natural Reserve (Buenos Aires). S. commersonii the conservation of the heritage of the six indige- is known for its genes for resistance/tolerance to biotic nous communities who inhabit the high elevation and abiotic stresses and is thus important for genetic valley, 3,200–5,000 meters above sea level, outside of improvement. Sajama (2017) ranked this wild species Cusco, Peru. The Potato Park is managed using the as the one with the highest priority for conservation Indigenous Biocultural Heritage Area (IBCHA) model actions as it is one of the wild potato species losing developed by Asociación ANDES, which incorporates the most geographical range. contemporary science and conservation models with a rights-based governance built on the ayllu political The geographic data retrieved for wild potato species and socio-economic system. The ayllu can be thought accessions from the INTA Active Germplasm Bank, of as a community linked through mutual and shared Balcarce (ARG1347) revealed that 67% of the Argen- respect of all elements in the natural surroundings, tine species of Solanum section Petota occurred in 18 such as humans, animals, rocks, spirits, rivers, lakes, protected areas distributed in 11 Argentinian prov- plants life, etc. (personal communication David Ellis, 2022). The Potato Park and CIP have had a long-term collab- orative agreement which includes the integration of science-based knowledge with the traditional knowl- edge of the five indigenous communities which make up the Potato Park and has involved a lasting relation- ship for the blending of ex situ and in situ conserva- tion. The communities maintain the diversity of over 1,000 potato landraces, about 450 of which were repa- triated from the CIP genebank as disease-free planting materials. CIP and the Papa Arariwa, or “Guardians of the Potato,” have collaborated over the years in scien- tific experiments to understand, and develop lasting tools to ensure, sustainability in the park, considering very rapid climatic changes. Most recently, using disease-free material maintained ex situ at CIP, these experiments have looked at the effects of planting native landraces along an elevational gradient up to 4,500 meters above sea level. Experiments start with meetings between CIP scientists and community members to design the experiments and determine the landraces that will be used. This collaborative effort extends from planning to planting, monitoring, Figure 5 .3 .2 .1. Potato diversity during a celebration of Dia de la harvesting and evaluating the experiments. By this Papa at the Potato Park. (Photo: Dave Ellis, 2013) GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 43 inces, with higher species richness in the Northwest challenges and limitations for supporting in situ areas (Clausen et al., 2018). The following parameters conservation of traditional landraces and wild species were monitored for S. kurtzianum during 2006–2014: of potato in the countries of origin. These include the number of plants per population, tuber sprouting following: behaviour, pollen viability, seed germination, Ampli- fied Fragment Length Polymorphism (AFLP) markers. More inventories required . Lack of information about Over the nine years of monitoring, pests (Epicauta number of distinct landraces, wild species and their spp.) causing plant defoliation were detected. The ecogeographic distribution, including missing infor- sprouting of tubers was found to be asynchronous, mation about genotype, economic value (tuber flavor, which could be an escape strategy for pest and disease texture, stress resistances) and vulnerability status of resistance. Population counts and pollen viability wild relatives and their habitats limits the possibilities showed significant variation between the years (Marfil for in situ conservation. Therefore, comprehensive et al., 2015). This work supports the revision and inventories are needed, and data must be publicly improvement of management plans and conservation accessible in databases. of these genetic resources. Support for on farm and in situ conservation . Specific Furthermore, Kozub et al. (2019) identified specific areas need to be identified as priority sites for wild characteristics during monitoring of four wild potato species and considered for national genetic reserves. species (S. acaule, S. boliviense, S. brevicaule, S. vernei) Marketing strategies and additional economic support in Los Cardones National Park (LCNP). However, for can compensate for lower profitability of products comprehensive conservation, the consolidation of a derived from varieties preserved on farm, and stimu- single genetic reserve for all the wild potato species in late farmers to grow traditional varieties and conserve LCNP is necessary. First steps have already been taken wild relatives in nearby areas. and a nature trail called “Sendero de la papa” has been established in the Valle Encantado sector, where Increase of training possibilities . Technical expertise the local communities but also tourists can visit and of farmers and guardians for in situ conservation and learn about wild potato species (Kozub et al., 2020). knowledge transfer must be improved among the plant genetic resources community. 5 .4 Current challenges of in situ conser- vation Availability of virus-free plant material . The avail- ability of healthy propagules is severely limited and Although many programs and projects have been chains must be improved to provide clean tubers of initiated in the last decades, there are still major local varieties to interested farmers. 44 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO 6 POTATO EX SITU COLLECTIONS 6 .1 Ex situ conservation and priorities 6 .2 Historic potato collection missions in genebanks Russia (RUS001). The first missions to systematically Although genebanks represent a very cost-efficient collect potato genetic resources in South America conservation approach, genebank operations can were carried out by Russian scientists involving Yurii face several challenges, including the loss of unique Voronov and Sergei Bukasov in 1925–1926, Sergei material and the risk of genetic erosion if germplasm Juzepczuk between 1926–1928 and Nikolai Vavilov in cannot be maintained and/or regenerated under 1930–1933 (Loskutov, 1999). The material was col- optimal conditions and/or other political or envi- lected in Colombia, Ecuador, Peru, Bolivia and Chile ronmental circumstances require re-organization (Ovchinnikova et al., 2011; Spooner et al., 2014) and (Fu, 2017). Following and complementing Fu (2017), was the basis for the first potato germplasm collection Figure 6.1.1 represents a prioritization of the gen- of the N. I. Vavilov Institute of Plant Industry (VIR) in ebank’s most important activities if processes have Leningrad, today the N. I. Vavilov Institute of Plant to be rationalized. Germplasm maintenance has the Genetic Resources (VIR) in St. Petersburg (Ovchin- highest priority, followed by germplasm regenera- nikova et al., 2011). After detailed analysis, Juzep- tion and duplication, data management, germplasm czuk and Bukasov (1929), Bukasov (1933) and Vavilov distribution, acquisition, gap analysis and collecting, (1935 ) concluded that potato was domesticated germplasm evaluation and characterization and sup- independently in the Peruvian-Bolivian plateau and portive research to improve germplasm collections. in southern Chile, and they proposed about 20 wild Depending on the type of accession (variety, breeding potato species progenitors that are endemic to these line, landrace, wild species), the management of countries. Later, between 1955–1990 Russian scien- potato collections is linked to the corresponding plant tists systematically collected more than 6,100 further organ to be preserved (seed, tubers, in vitro plantlets, accessions of wild and cultivated potato species in ten shoot tips) and the aspects are addressed in the listed South American countries (Gorbatenko, 2006). chapters. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 45 International Potato Center genebank. Lima, Peru. Photo: Luis Salazar/Crop Trust Germplasm see chapter 11 lower improvement Suppor ve research Germplasm evalua on see chapter 11 Germplasm characterisa on Genebank Management Germplasm acquisi on, gap analysis & finding see chapter 10 Priori es Germplasm distribu on see chapter 8 Data management see chapter 9 Germplasm regeneraon & duplica on see chapter 8 high Germplasm maintenance (seed, tubers, in vitro plantlets, shoot ps) see chapter 7 M. Nagel (2022) Figure 6 .1 .1 . Management priorities in genebanks and relevant chapters for potato conservation management. Adapted and modified from Fu (2017). Germany (DEU159) organized several expeditions (Bamberg et al., 2003). Therefore, collecting missions to collect potatoes, among other crops, including were conducted within the USA. Since the 1990s, the missions to Chile and Bolivia in 1930–31 (Müntz late D.M. Spooner contributed significantly to the and Wobus, 2013), 1958 to Central America, 1988 taxonomic classification of Solanaceae species and to Peru and Colombia and 1989 to Peru. Since 1949, organized several collecting missions, together with the material has been maintained at the Groß Lüse- colleagues from Guatemala, the Netherlands (NLD037) witz Potato Collections (GLKS) near Rostock, and in and Germany (DEU159) (Spooner and Hijmans, 2001). 1998 the potato varieties collection of Braunschweig Wild potato germplasm was collected in almost Genetic Resources Center (BGRC, DEU001), were inte- all Latin American countries including Guatemala grated with this. Currently, the GLKS comprise 2,845 (Spooner et al., 1998), Argentina, Bolivia, Chile, accessions from South and Central America and over Colombia, Costa Rica, Ecuador, Honduras, Mexico, 2,800 accessions of cultivated potatoes from Europe Panama, Peru, and Venezuela (Spooner and Hijmans, and North America. Intensive work on the taxonomy 2001). of S. tuberosum L. was carried out in particular by S. Danert in the 1950s and 60s (Gäde, 1998). Netherlands (NLD037). The CGN potato collection is the successor of the German-Dutch potato collection United Kingdom (GBR251) . Parts of Scotland were at DEU001, which was established in 1974 by merging severely affected by late blight in the 1840s. When the ‘Erwin Baur Sortiment’ from DEU063 (Max-Planck blight-resistant hybrids were discovered in the Royal Institute in Cologne) and the Wageningse Aardappel Botanic Garden in Edinburgh, British expeditions Collectie (WAC) from NLD002. It includes germplasm were sent to Mexico and South America between from the Dutch expeditions in 1955 and 1974 and 1938–1939. The collectors, including the British material from missions of DEU063 collecting wild and taxonomist Jack G. Hawkes, were particularly inter- native Andean potatoes in Argentina, Bolivia, Peru ested in the cultivation of potatoes from true seeds in and Ecuador in 1959 (Ross, 1960; Ross and Rimpau, southern Colombia and northern Ecuador. A total of 1960). 1,164 accessions of wild and cultivated potato species were collected in Argentina, Bolivia, Peru, Ecuador, It was substantially expanded with germplasm from Colombia and Mexico (Hawkes, 1941) and formed the the Argentine genebank of INTA-Balcarce, mainly basis of the so-called Commonwealth Potato Collec- collected by K.A. Okada, and by a collecting mission in tion (CPC), which is now held at the James Hutton Bolivia in 1980 by DEU001 (Soest et al., 1983). Further Institute at Invergowrie Dundee, Scotland. collecting missions were conducted together with the USA (Spooner et al., 1998). Today, the collection holds USA (USA004). The U.S. Potato Genebank was estab- 2,700 potato accessions from 12 American countries. lished in the late 1940s with the aim of avoiding the About 55% of this collection meets EU plant health import of varieties from abroad that might pose a requirements for distribution of germplasm. Limited threat to the potato industry or endemic wild spe- phytosanitary testing capacity at the Dutch Plant cies. Two species were found to originate in the USA Health Service hampers rejuvenation. In 2004, some 46 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO of this material was repatriated to the potato col- • Latin America: Argentina (1), Brazil (1), Chile (1), lection of the National Gene Bank of Andean Tubers Colombia (1), Cuba (1), Ecuador (1), Guatemala (1), and Roots, maintained by PROINPA in Bolivia (Cadima Peru (1), Fuentes et al., 2017). • North America: Canada (1), USA (1) • International Center: CIP (1) International Potato Center (PER001) . The Interna- tional Germplasm Bank for potato was established The information collected was processed by the lead at the International Potato Center (Centro Interna- coordinator (as data controller) and carried out as cional de la Papa, CIP) in Lima, Peru in the early 1970s. scientific research in the public interest. Upon com- In close collaboration with the Peruvian National pletion, all data was transferred to the Crop Trust. Institute for Agricultural Research (INIA) (Huaman In accordance with Regulation 2016/679 (GDPR) and et al., 2000) and well-known international scientists local data protection law (in the EU), participants like J.B. Bamberg, J.G. Hawkes, A.M. Van Harten, J.P. have the rights to access, modify, erase and transfer Hjerting, W. Hondelmann, R. Hoopes, K.A. Okada, (when applicable) personal data, as well as the right A. Salas, D. Spooner, and J.J.C. Van Soest, more than to restrict and object to its processing. They also have 300 systematic exploration missions (Spooner et al., the right to withdraw their consent at any time and 2014) and more than 100 collecting missions in more to submit a complaint directly to the appropriate data than 12 countries were carried out (Huaman et al., protection supervisory authority. 2000). Many of these were funded by the Interna- tional Board for Plant Genetic Resources (later the National germplasm banks are often embedded in International Plant Genetic Resources Institute). Carlos institutional and departmental structures, and it can M. Ochoa of CIP spent his entire career working on be difficult to contact curators. Therefore, contacts the systematics of wild potatoes and, with Alberto for potato germplasm collections are provided here, Salas, led many missions for the Universidad Nacional based on information from websites or from partici- Agraria La Molina, and later for CIP (Spooner et al., pants who consented to the publication of these data 2014). More recently (2017–2018), in collaboration (Table 6.3.1). with INIA, CIP co-led 18 collecting missions for potato crop wild relatives throughout Peru, which yielded 322 6 .4 Ex situ collections potato accessions of 26 species according to Spooner taxonomy. Worldwide, a total of 82,293 potato accessions are maintained in 89 institutions and four international/ 6 .3 Information on the potato germ- regional centers in 59 countries (Figure 6.4.1; WIEWS plasm collections and the survey (2021) and survey data). The active conservation of potato accessions is the result of numerous missions The World Information and Early Warning System to collect landraces and wild species in Latin America on Plant Genetic Resources for Food and Agricul- between 1930–2020. In addition, improved varieties ture (WIEWS) assesses the status of conservation and and breeding lines have been added to the published use of plant genetic resources (WIEWS, 2021) and inventory of national and international genebanks. provides contact information and collection data of Forty-seven institutes in 36 countries keep more than participating genebanks. According to these data, 86 100 accessions and just five countries (France, Ger- institutes preserve between 1 and 12,100 potato acces- many, India, Russia, USA) together with the Interna- sions. To increase our knowledge of the composition, tional Potato Center (CIP, PER001) in Peru hold more safety, data availability and conservation challenges than 50% of all potato accessions. and objectives of the different potato germplasm col- lections and to update the first global strategy for the Most, and the largest, collections are found in Europe conservation of potato (van Soest, 2006), 48 institutes (Table 6.3.1), with 12,120 accessions preserved at the were contacted and a survey was conducted. A ques- Institute for Genetics, Environment and Plant Protec- tionnaire (Annex 1) was sent out in 2020 and 2021. A tion in France (INRAE, FRA010), 8,150 accessions at total of 24 participants completed the survey in 2020 the N.I. Vavilov All-Russian Institute of Plant Genetic and eight participants in 2021 from the germplasm Resources (VIR, RUS001) in Russia, 6,289 accessions at collections of: the Leibniz-Institute of Plant Genetics and Crop Plant • Asia: India (1 institution), China (2), Japan (1) Research (IPK, DEU159) in Germany, 2,638 accessions • Europe: Belgium (1), Bulgaria (1), Czech Republic at the Potato Research Institute Havlickuv Brod in (1), Estonia (1), France (1), Germany (1), Ireland (2), the Czech Republic (CZE027), 1,634 accessions at the Netherlands (1), Latvia (1), Romania (1), Russia (1), Center for Genetic Resources (CGN, NLD037) of the Slovenia (1), Spain (1), Sweden (1), United Kingdom Netherlands, and 1,523 accessions at the James Hutton (2) Institute (GBR251) in UK. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 47 Table 6 .3 .1 . International and national potato germplasm collections and curator contacts based on the survey data, publicly avail- able websites and information from WIEWS (2021). Code Institution Curator Organization Number of Accessions ARG1347 Instituto Nacional de Tecnología Agropecuaria (INTA) Ariana Digilio Governmental 1,550 Banco Activo de Germoplasma, Agricultural digilio.ariana@inta.gob.ar Experimental Station Balcarce Ruta 226 km 73,5 Balcarce 7620 Argentina https://inta.gob.ar/documentos/banco-activo-de- germoplasma-de-la-eea-balcarce BEL023 Walloon Agricultural Research Center (CRA-W) Alice Soete Governmental 123 Le laboratoire Pomme de Terre In Vitro a.soete@cra.wallonie.be Rue du Serpont, 100 Libramont 6800 Belgium https://www.cra.wallonie.be/en BGR001 Institute of Plant Genetic Resources “Konstantin Stanislava Stateva Research 431 Malkov” (IPGR) National Genebank stanislava.stateva@gmail.com Institute 2 Druzhba Str. Sadovo 4122 Bulgaria http://ipgrbg.com/en/ BLR016 Republican Unitary Enterprise ‘Research and belbulba@belbulba.by 1,570* Practical Center of the National Academy of Sciences of Belarus for Potato, Fruit and Vegetable Growing’ 2-a Kovalev street, 2a 223013 Samokhvalovichy, Minsk district, Minsk Region Belarus https://nasb.gov.by/eng/about/otdeleniya-nauk/agro. php BOL317 National Institute for Agricultural and Forestry contacto@iniaf.gob.bo 1,567* Innovation (INIAF) Calle Cañada Strongest, Zona San Pedro casi esquina Otero de la Vega, N°1573 La Paz Bolivia https://www.iniaf.gob.bo BRA020 Embrapa Clima Temperado Caroline Marques Castro Governmental 389 Rodovia BR 392, Km 78, 9º Distrito, Monte Bonito caroline.castro@embrapa.br Pelotas / RS 96015-420 Brazil https://www.embrapa.br/clima-temperado CAN064 Agriculture and Agri-Food Canada (AAFC) Benoit Bizimungu Governmental 193 Fredericton Research and Development Center Benoit.Bizimungu@canada.ca (Fredericton RDC), Canadian Potato Genetic Resources 850 Lincoln Road, P.O. Box 20280 Fredericton E3B 4Z7 Canada https://pgrc-rpc.agr.gc.ca/gringlobal/search.aspx 48 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Code Institution Curator Organization Number of Accessions CHL071 Instituto de Investigaciones Agropecuarias (INIA) Manuel Andrés Muñoz David Governmental 866 Ruta 5 Sur, Km 8 Norte manuel.munozd@inia.cl Osorno, Los Lagos Chile http://www.recursosgeneticos.com/ CHL179 Universidad Austral de Chile (UACh) Anita Pia Behn 837* Institute of Plant Production and Protection anita.behn@uach.cl Potato Germplasm Bank Valdivia Región de Los Rios Chile http://www.potatogenebank.cl/ CHN116 Heilongjiang Academy of Agricultural Sciences Liu Xicai Governmental 2,206 (HAAS) Keshan branch of HAAS, Potato Resources Institute kslxc@sina.com Keshan 161606 China http://www.hljnkyksfy.cn/ CHN122 Chinese Academy of Agricultural Sciences (CAAS) Liping Jin Governmental 2,064 Institute of Vegetable and Flowers (IVF) jinliping@caas.cn 12 Zhongguancun Nandajie Beijing 100081 China http://ivf.caas.cn COL017 Corporación colombiana de investigación Zahara Lasso Paredes Governmental, 1,570 agropecuaria (AGROSAVIA) & Research Institute Banco de Germoplasma Vegetal zlasso@agrosavia.co Mixed Km 14 vía Paula Helena Reyes organization Mosquera - Bogotá, Cundinamarca phreyes@agrosavia.co 250047 Colombia https://www.agrosavia.co/ CUB005 Instituto Nacional de Ciencias Agrícolas Jorge Luis Salomon Diaz Governmental 1,206 Carretera Tapaste Km 3.5 salomon@inca.edu.cu San José de las Lajas Mayabeque 32700 Cuba www.inca.edu.cu CZE027 Potato Research Institute Havlickuv Brod Jaroslava Domkarova Private 2,638 Department of Genetic Resources domkarova@vubhb.cz Dobrovskeho 2366 Havlickuv Brod 58001 Czech Republic https://www.vubhb.cz/en GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 49 Code Institution Curator Organization Number of Accessions ECU023 Instituto Nacional de Investigaciones Agropecuarias Álvaro Monteros Governmental 1,341 (INIAP) Departamento Nacional de Recursos Fitogenéticos alvaro.monteros@iniap.gob.ec (DENAREF) Panamerica sur km 1 - Vía a Tambillo, Cantón Mejía, Provinz Pichincha Quito 170401 Ecuador http://www.iniap.gob.ec/ EST019 Estonian Crop Research Institute Kristiina Laanemets Governmental 786 M. Pilli haru 1 kristiina.laanemets@etki.ee Jõgeva 48309 Estonia https://etki.ee/en/ FRA010 INRAE, IGEPP, the Institute for Genetics, Esnault Florence Governmental 12,120 Environment and Plant Protection Amélioration de la Pomme de Terre, 29260 florence.esnault@inrae.fr Domaine de Keraïber Ploudaniel 29260 France https://www6.rennes.inrae.fr/igepp_eng/ DEU159 Leibniz Insitute of Plant Genetics and Crop Plant Klaus J. Dehmer Non-university 6,247 Research (IPK) Groß Lüsewitz Potato Collection (GLKS) dehmer@ipk-gatersleben.de Research Parkweg 3a gbis-info@ipk-gatersleben.de Institute Sanitz OT Gross Luesewitz 18190 Publicly funded Germany https://www.ipk-gatersleben.de/en/research/ genebank/satellite-collections-north GBR251 The James Hutton Institute Gaynor McKenzie Governmental 1,523 Potato Germplasm Collection gaynor.mckenzie@hutton.ac.uk Invergowrie Dundee DD2 5DA Great Britain https://potato.hutton.ac.uk/topics/resources GBR165 Science & Advice for Scottish Agriculture (SASA) Heather Campbell Governmental 1,475 Roddinglaw Road heather.campbell@sasa.gov.scot Edinburgh EH12 9FJ Great Britain https://www.sasa.gov.uk/ GTM001 Instituto de Ciencia y Tecnología Agrícolas (ICTA) María de los A. Mérida Guzman Governmental 242 Banco de Germoplasma mmerida@icta.gob.gt Km. 21.5 Carretera hacia el Pacifico Eleonara Ramírez Bárcena, Villa Nueva 09001 eleonoraramirez@icta.gob.gt Guatemala Osman Cifuentes https://www.icta.gob.gt/ osmancifuentes@icta.gob.gt IND665 ICAR-Central Potato Research Institute (CPRI) Vinay Bhardwaj Governmental 4,257 Central Potato Research Institute vinay.bhardwaj@icar.gov.in Himachal Pradesh Shimla 171001 India https://cpri.icar.gov.in/ 50 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Code Institution Curator Organization Number of Accessions IRL036 Department of Agriculture, Food & the Marine Gerry Doherty Governmental 700 Raphoe Potato Labratory gerry.doherty@agriculture.gov.ie Raphoe Co. Donegal F93 HV02 Ireland https://www.gov.ie/en/organization/department-of- agriculture-food-and-the-marine/ IRL012 The Agriculture and Food Development Authority Denis Griffin Governmental 600 (Teagasc) Oak Park denis.griffin@teagasc.ie Carlow R93 XE12 Ireland https://www.teagasc.ie/ JPN183 Research Center of Genetic Resources www@naro.affrc.go.jp Governmental 1,890 National Agriculture and Food Research Organization (NARO) 2-1-2 Kannondai Tsukuba, Ibaraki 305-8602 Japan https://www.naro.go.jp/english/laboratory/ngrc/ LVA006 Institute of Agricultural Resources and Economics Ilze Dimante Research 155 Priekuli Research center ilze.dimante@arei.lv Institute Zinātnes 2 Priekuli LV 4126 Latvia https://www.arei.lv/lv PER001 International Potato Center (CIP) Vania Azevedo (Genebank Head) NGO 7,467 Genetic Resources Unit vania.azevedo@cgiar.org Avenida La Molina 1895 Julian Soto (Potato CWR curator) Lima 12 j.soto@cgiar.org 15023 Rene Gomez (Cultivated potato curator) Peru r.gomez@cgiar.org https://cipotato.org PER860 Instituto Nacional de Innovación Agraria (INIA) Elizabeth Fernandez Huaytalla (in Governmental 559 vitro) Av la Molina N° 1981 fcarrillo@inia.gob.pe Lima 2791 Peru https://www.inia.gob.pe POL002 Bonin Research Center Włodzimierz Przewowski 1,395* Potato Gene Resources and Tissue Culture w.przewodowski@ihar.edu.pl Laboratory Plant Oddział w Boninie Bonin 3 Bonin 76-009 Poland www.ziemniak-bonin.pl ROM007 Banca de Resurse Genetice Vegetale „Mihai Cristea” Dana Constantinovici Governmental 153 (BRGV) Bdul 1 Mai, Banca de Gene, 17 dana.constantinovici@svgenebank. ro Suceava 720224 svgenebank@upcmail.ro Romania https://svgenebank.ro/ GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 51 Code Institution Curator Organization Number of Accessions RUS001 N.I. Vavilov All-Russian Institute of Plant Genetic Elena Rogozina (field) Governmental 8,150 Resources (VIR) Bolshaya Morskaya st., 42, 44 erogozina@vir.nw.ru St. Petersburg Tatjana Gavrilenko (in vitro & cryo) 190031 tatjana9972@yandex.ru Russian Federation http://www.vir.nw.ru/en/ SVN019 Kmetijski inštitut Slovenije Peter Dolničar Governmental 32 Hacquetova ulica 17 peter.dolnicar@kis.si Ljubljana 1000 Slovenia https://www.kis.si/en/ ESP016 NEIKER - Basque Research and Technology Alliance Jose Ignacio Ruiz de Galarreta Governmental 292 Arkaute Agri-food Campus jiruiz@neiker.eus Vitoria 01192 Spain https://neiker.eus/en/ SWE054 The Nordic Genetic Resource Center (NordGen) Pawel Chrominski Governmental 94 Växthusvägen 12 pawel.chrominski@nordgen.org Alnarp 234 56 Sweden https://www.nordgen.org/en/ NLD037 Wageningen University & Research (WUR) Roel Hoekstra Research 1,634 Center for Genetic Resources the Netherlands roel.hoekstra@wur.nl Institute P.O. Box 16 Wageningen 6700 AA The Netherlands https://www.wur.nl/en/Research-Results/Statutory- research-tasks/Center-for-Genetic-Resources-the- Netherlands-1/Genebank/CGN-crop-collections/ CGN-potato-collection.htm USA004 US Department of Agriculture (USDA) John Bamberg Governmental 5,900 US Potato Genebank John.Bamberg@usda.gov 4312 Highway 42 Alfonso Del Rio Sturgeon Bay, Wisconsin 54235 adelrioc@wisc.edu USA   https://www.ars.usda.gov/midwest-area/     madison-wi/vegetable-crops-research/people/john- bamberg/bamberg-lab/ UKR026 Ukrainian Academy for Agricultural Sciences Mykola Furdyga 2,229* Ukrainian Institute for Potato Research upri@visti.com 22 Chkalov Street Nemishaevo Borodyanka, Kiev region 7853 Ukraine 52 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Important collections are also held in Latin American the last survey (van Soest, 2006) (Table 6.4.1). Signifi- countries, in the countries of origin, representing cant increases were recorded by: 15% of the global total. Thereby, 1,555 accessions are • France (FRA010; +88%; +5,670 accessions) maintained in Chile at the Instituto de Investigaciones • India (IND665; + 62%, +1,629 accession) Agropecuarias (INIA, CHL071) and the Universidad • China (CHN122; +143%, +1,214 accessions) Austral de Chile (UACH, CHL179), 1,570 accessions in • Peru (PER867, +89.7%; +565) accessions) Colombia at the Corporacion Colombiana de Inves- tigacion Agropecuaria (CORPOICA, COL017), 1,561 In contrast, some countries/institutions showed accessions in Argentina at the Instituto Nacional de decreases in the number of accessions. CIP (PER001) Tecnología Agropecuaria (INTA, ARG1347), 1,567 preserved 10,308 accessions in 2006 and 7,467 acces- accessions in Bolivia at the Instituto Nacional de Inno- sions in 2020 (-28%), due to a rationalization of vación Agropecuaria y Forestal (INIAF, BOL317) and the collection and elimination of duplicates. CGN 1,754 accessions in Peru at the Instituto Nacional de (NLD037) reduced its collection by 1,082 (-40%) and Innovación Agraria (INIA, PER860) and the Asociación in Bolivia the potato collection was transferred from para la Naturaleza y el Desarrollo Sostenible, an NGO PROINPA (BOL055) to INIAF (BOL317) and shows an (ANDES, PER867). The US Potato Genebank at the overall reduction of 640 accessions (-29%). However, USDA (USA004) is the largest holder in North America in some countries, e.g. Bolivia, the transfer of potato with 5,934 accessions. collections between institutions is difficult to track and the current status may not be fully reflected by In Asia, China preserves 4,270 accessions at the Hei- the available numbers. longjiang Academy of Agricultural Sciences (HAAS, CHN116) and the Chinese Academy of Agricultural 6 .5 Biological status of potato acces- Sciences (CAAS, CHN122), India 4,259 accessions at the sions ICAR-Central Potato Research Institute (CPRI, IND665) and Japan 1,890 accessions at the Research Center Overall, most accessions are breeding lines (27%), of Genetic Resources, National Agriculture and Food followed by landraces (23%) and improved varieties Research Organization (NARO, JPN183). (25%) and wild species (20%) (Figure 6.5.1). Institu- tions holding a large number of breeding lines, land- The uneven distribution of potato accessions in ex races, improved varieties and wild species in parallel situ genebanks on different continents may reflect are located in Russia (RUS001), Germany (DEU159), the need of the potato industry for plant genetic Peru (CIP, PER001), USA (USA004) and the Netherlands resources for their breeding programs. (NLD037) (Figure 6.5.2), and are mainly collections that were established in the early 20th century. Compared The number of accessions maintained has increased by to the last survey (van Soest, 2006) (Table 6.4.2), the 42.0% (WIEWS (2021) and survey data) compared to numbers of breeding lines (+107%) and improved Interna onal/Regional (7,620 acc; 9 %) North America (6,144 acc; 8 %) USA (5,934) Canada (210) Asia (10,800 acc; 13 %) Europe (45,480 accessions; 55 %) China (4,270) France (12,120) India (4,259) Russian Federaon (8,150) Japan (1,890) Germany (6,289) Philippines (165) UK (3,072) Ukraine (2,795) Czechia (2,638) La n America (12,236 acc; 15 %) Poland (1,934) Peru (1,754) Belarus (1,656) Colombia (1,570) Netherlands (1,634) Bolivia (1,567) Ireland (1,300) Argen na (1,561) Estonia (1,177) Chile (1,555) Romania (1,012) Ecuador (1341) Bulgaria (431) Cuba (1206) Spain (392) Mexico (830) Switzerland (243) Brazil (453) Norway (158) Guatemala (242) Latvia (155) Panama (147) Belgium (124) Figure 6 .4 .1 . Overview of potato collections by continent and country. Countries preserving more than 100 accessions are shown. Data include survey data and institutes listed in the World Information and Early Warning System on Plant Genetic Resources for Food and Agriculture (WIEWS). WIEWS ©FAO 2021, http://www.fao.org/wiews/en/, accessed on 20th Sept 2021. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 53 54 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Table 6 .4 .1 . Number of potato accessions, number of species for each category and changes in percentage compared to the last survey (van Soest, 2006) are listed for each institution contributing to the survey (*). In addition. data the World Information and Early Warning System on Plant Genetic Resources for Food and Agriculture (WIEWS). WIEWS ©FAO 2021, http://www.fao.org/wiews/ en/. accessed on 20 September 2021. Institute code Country Wild species % Landrace % Breeding line % Improved variety % unknown Total % FRA010* France 620 (26) 3.3 300 (1) 20.0 10000 117.4 1200 (1) 20.0   12120 87.9 RUS001* Russian Federation 1990 (98) -35.8 3200 (11) -5.9 600 200.0 2360 (1) 12.4 8150 -7.4 PER001* International 2596 (144) 9.9 4468 (7) 0.2 31 -99.0 372 (?) 18.5 7467 -27.6 DEU159* Germany 1357 (130) 0.6 2270 (7) 32.7 638 -19.9 1943 (2) -2.3 39 6247 6.0 USA004* USA 4044 (90) 6.7 1177 (5) 15.2 371 -30.5 308 (1) -1.3 5900 4.3 IND665* India 340 (105) -13.9 107 (?) -88.4 96 1143.5 2952 (?) 138.1 762 4257 62.0 CZE027* Czechia 136 (23) -53.6 20 (1) 566.7 933 75.7 1361 (2) 22.5 188 2638 29.0 UKR026 Ukraine 455 (60) 23 (1) 846 352 (2) 553 2229 CHN116* China 12 (?) 43 (?) 1451 700 (?) 2206 CHN122* China 54 (14) -64.0 23 (1) 1600 300.0 387 (1) 29.0 2064 142.8 JPN183* Japan 37 (17) -70.9 42 (5) 68.0 1476 4667.7 333 (1) -79.9 2 1964 2.6 NLD037* Netherlands 1302 (118) -33.6 298 (4) -59.7 5 126.7 29 1634 -39.8 COL017* Colombia 274 (9) 153.7 1196 (1) 30.7 44 -42.0 42 (1) 16.7 1570 35.5 BLR016 Belarus 577 (78) 138 855 (1) 1570 BOL317 Bolivia -100.0 1567 (9) 11.9 -100.0 -100.0 1567 -29.0 ARG1347* Argentina 1060 (31) -27.4 411 (3) -25.4 67   12 (1)   0 1550 -22.9 GBR251* UK 686 (86) -24.8 340 (4) -50.9 497 1523 -5.0 GBR165* UK 25 1450 (1) 1475 POL002 Poland 1395 (1) 1395 ECU023* Ecuador 166 (10) -39.6 602 (3) 171.2 550 23 (3) 64.3 0 1341 162.4 CUB005* Cuba 63 (12)   16 (1)   650   438 (2)   39 1206   PER867 Peru 785 (5) 153.2 410 36.7 -100.0 1195 89.7 CHL071* Chile 486 (1) 287 13 (1) 80 866 MEX208 Mexico 9 (4) 96 (1) 708 813 EST019* Estonia 1 (1) 55 (1) 310 400 (1) 20 786 ROM018 Romania 12 (1)           704 (1)     716   IRL036* Ireland 700 (1) 700 CHL179 Chile -100.0 -100.0 -54.1 -100.0 689 689 -67.1 IRL012* Ireland 100 500 (90?) 0 600 UKR008 Ukraine 7 (1) 10 537 (1) 12 566 GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 55 Institute code Country Wild species % Landrace % Breeding line % Improved variety % unknown Total % PER860* Peru 322 (55)   237 (1)             559   POL047 Poland 8 (2) 422 5 435 BGR001* Bulgaria 89 (1) 336 6 (1) 0 431 EST006 Estonia 1 73 17 300 391 BRA020* Brazil 92 (3) 153 127 (1) 17 389 ESP016* Spain 32 (28)   92 (2) -20.7 20   148 (2)   0 292 151.7 GTM001* Guatemala 12 (5) 35 (2) 28 153 (1) 14 242 CAN064* Canada 21 71.6 78 (1) 50.0 94 193 62.2 PHL303 Philippines 80 13 (1) 66 159 LVA006* Latvia 12 (1) 89 54 (1) 0 155 ROM007* Romania 2 (1)   150 (1) 0.0 0   1 (1)   0 153 2.0 PAN147 Panama 1 (1) 3 (1) 119 24 (1) 147 ROM028 Romania 8 134 (1) 142 BEL023* Belgium 14 36 42 10 21 123 CHE001 Switzerland 121 121 NOR061 Norway                 111 111   POL003 Poland 104 (28) 104 ESP172 Spain 1 (1) 93 (4) 6 100 MNG030 Mongolia 8 (1) 19 72 (1) 99 SWE054* Sweden 39 (1) 9 28.6 46 (1) -19.3 94 46.9 BLR029 Belarus         86         86   GBR004 UK 73 (14) 1 74 CHE063 Switzerland 65 65 BRA003 Brazil 37 (2) 7 (1) 20 64 CHE002 Switzerland 57 57 FJI049 Fiji     54 (2)             54   MNE001 Montenegro 52 (1) 52 LKA036 Sri Lanka 1 (1) 6 (1) 30 12 49 NOR035 Norway 47 47 KGZ040 Kyrgyzstan 45 (2) 45 ARM059 Armenia         15   6 (1)   20 41   PRT102 Portugal 32 (1) 8 40 SVN019* Slovenia -100.0 32 (1) -47.5 32 -64.8 56 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Institute code Country Wild species % Landrace % Breeding line % Improved variety % unknown Total % USA016 USA 11 (2) 10 21 BGD215 Bangladesh 9 (1) 11 20 DEU401 Germany             18 (1)     18   MEX006 Mexico 17 (8) 17 CAN004 Canada 16 1 17 ITA368 Italy 16 (1) 16 DEU483 Germany 14 (1) 14 LTU001 Lithuania         14         14   ARG1342 Argentina 8 (3) 2 (1) 1 (1) 11 ZAF062 South Africa 1 (1) 8 (1) 9 USA995 USA 1 (1) 7 8 URY003 Uruguay 7 7 DEU567 Germany             6 (1)     6   PHL131 Philippines 6 6 TWN001 International 5 5 USA176 USA 5 (1) 5 HRV041 Croatia 4 (1) 4 DEU526 Germany             4 (1)     4   HND029 Honduras 2 (1) 2 IND001 India 2 2 LSO015 Lesotho 2 2 AZE007 Azerbaijan 1 1 BEL002 Belgium                 1 1   SWZ015 Eswatini 1 (1) 1 GUY021 Guyana 1 1 LBN020 Lebanon 1 (1) 1 MLT001 Malta 1 (1) 1 ROM023 Romania     1 (1)             1   TJK027 Tajikistan 1 (1) 1 TZA016 Tanzania 1 (1) 1   WIEWS 2021 1338   2747   2241   4586.0   2528.0 13440   Survey Data 15212 15744 19932 16149.0 1816.0 68853   Total 16550 -5 .8 18491 7 .4 22173 107 .1 20735 100 .2 4344 82293 42 .0 varieties (+100%) in particular has increased, while with the highest number of different species, are the number of accessions of landraces has increased held by CIP (PER001; 144 species; 2,596 accessions), only a little (+7%) and has decreased by -5.8% for Germany (DEU159; 130 species; 1,357 accessions), the wild species. However, if data are only obtained Netherlands (NLD037; 118 species; 1,302 accessions) through WIEWS (2021) (see also Figure Annex A3), a and Russia (RUS001; 89 species; 1,990 accessions) lower number of breeding lines (only one third) and (Figure 6.4.2). The USA (USA004) follows the Spooner improved varieties (only half) and a higher number of et al. (2014) classification and has a collections of 90 unknown accessions are visible in the system (Figure species and 4,044 accessions. Compared to the last 6.5.1, Figure Annex A3). survey (van Soest, 2006), only a few institutions have increased or maintained the number of accessions pre- Analysis of data on biological status and the number served. The largest increase was recorded in the USA of species is hampered by the different taxonomic (USA004) with 253 accessions (+7%) and CIP (PER001) classification systems currently in use. Although with 233 accessions (+10%) in 2020. In most countries, RUS001 applies the classification system of Bukasov a reduction in the number of accessions of wild species (1978), most genebanks follow the Hawkes (1990) was reported. In Russia (RUS001), the number of wild taxonomy, which accepts 228 wild species. However, accessions reduced by -1,100 accessions (-36%), in Cze- some genebanks, e.g. the USA, have already changed chia (CZE027) -157 fewer accessions were registered to the classification system proposed by Spooner et al. (-54%). In other countries, e.g. Bolivia, it is not clear (2014), which allows 107 wild species. For cultivated whether the collections have been transferred and species, Spooner et al. (2014) accepts four species maintained in another institution. In summary, the instead of seven, namely: (1) S. tuberosum including conservation of wild species has mostly experienced the ‘Andigenum group’ and the ‘Chilotanum group’; negative changes, and it is not clear whether the (2) S. ajanhuiri; (3) S. juzepczukii; and (4) S. curti- decline in numbers is due to rationalization processes, lobum. For comparisons, taxonomic classification of loss or a transfer of material. the genebank accessions listed in WIEWS (2021) were transferred to the system used by Spooner et al. (2014) The highest number of different wild species is still (Table Annex A4). maintained by CIP (PER001; 95 species) when only the classification of Spooner et al. (2014) is used and data Wild species available from WIEWS (2021) are considered (Table Annex A4). According to these criteria (which differ In total, 20% of all potato collections (16,550 acces- slightly from (WIEWS (2021) plus survey data), other sions) consist of wild species classified into 223 species collections with a high number of different species (WIEWS (2021) plus survey data), which are commonly are the USA (USA004; 79 species), Russia (RUS001; 70 conserved through seeds (Table 6.3.1; Table Annex species), Germany (DEU159; 66 species) and the Neth- A3). The largest collections of wild potato species, erlands (NLD037; 60 species), which largely confirms WIEWS WIEWS & Survey (52,163 accessions) (82,293 accessions) Wild species (14,401 acc; 27.6 %) Unknown Unknown Improved variees (4,344 acc; 5.3 %) (5,733 acc; 11.0 %) (20,735 acc; 25.2 %) Wild (16,550 acc; 20.1 %) Improved varie es (9,106 acc; 17.5 %) Landraces Breeding lines (18,491 acc; 22.5 %) (6,752 acc; 12.9 %) Breeding lines Landraces (22,173 acc; 26.9 %) (16,171 acc; 31.0 %) Figure 6 .5 .1 . Biological status of the potato collections listed in the World Information and Early Warning System on Plant Genetic Resources for Food and Agriculture (WIEWS) (left) ©FAO 2021, http://www.fao.org/wiews/en/, accessed on 20 Sept 2021 and additional data obtained by the survey (right). GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 57 Institute code Country Wild species % Landrace % Breeding line % Improved variety % unknown Total % USA016 USA 11 (2) 10 21 BGD215 Bangladesh 9 (1) 11 20 DEU401 Germany             18 (1)     18   MEX006 Mexico 17 (8) 17 CAN004 Canada 16 1 17 ITA368 Italy 16 (1) 16 DEU483 Germany 14 (1) 14 LTU001 Lithuania         14         14   ARG1342 Argentina 8 (3) 2 (1) 1 (1) 11 ZAF062 South Africa 1 (1) 8 (1) 9 USA995 USA 1 (1) 7 8 URY003 Uruguay 7 7 DEU567 Germany             6 (1)     6   PHL131 Philippines 6 6 TWN001 International 5 5 USA176 USA 5 (1) 5 HRV041 Croatia 4 (1) 4 DEU526 Germany             4 (1)     4   HND029 Honduras 2 (1) 2 IND001 India 2 2 LSO015 Lesotho 2 2 AZE007 Azerbaijan 1 1 BEL002 Belgium                 1 1   SWZ015 Eswatini 1 (1) 1 GUY021 Guyana 1 1 LBN020 Lebanon 1 (1) 1 MLT001 Malta 1 (1) 1 ROM023 Romania     1 (1)             1   TJK027 Tajikistan 1 (1) 1 TZA016 Tanzania 1 (1) 1   WIEWS 2021 1338   2747   2241   4586.0   2528.0 13440   Survey Data 15212 15744 19932 16149.0 1816.0 68853   Total 16550 -5 .8 18491 7 .4 22173 107 .1 20735 100 .2 4344 82293 42 .0 (2 022) gel M. N a 58 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO NOR061 DEU159 SWE054 CZE027 EST019 POL002 NLD037 LVA006 RUS001 CAN064 GBR251 BEL023 BLR016 IRL036 IRL012 USA004 SVN019 ESP016 ROM007 UKR026 CHN122 CUB005 JPN183 BGR001 CHN116 MEX208 PAN147 GTM001 FRA010 IND665 COL017 PHL303 ECU023 BRA020 PER001 PER860 PER867 Number of accessions 100) Wild species BOL317 ARG1347 1- 101- 501- 1001- 2501- 7501 - 12000 CHL071 300) Landraces CHL179 100 500 1000 2500 7500 400) Breeding lines 500) Improved variees not specified did not report, but data in WIEWS Figure 6 .5 .2 . Number and category of potato accessions listed for each institute contributing to the survey. In addition, institutes listed in the World Information and Early Warning System on Plant Genetic Resources for Food and Agriculture (WIEWS) having > 150 accessions are shown. WIEWS ©FAO 2021, http://www.fao.org/wiews/en/, accessed on 20 Sept. 2021. the data generated by the survey. Most accessions UK (GBR251) by -352 accessions (-50%), in Argentina belong to S. brevicaule Bitter (1,896 accessions), which (ARG1347) by -140 accessions (-25%) and in Russia by were combined from 19 different species accepted -200 accessions (-6%). In some cases, the reduction of by Hawkes (1990). Among these species, S. brevi- landraces was reported to be due to a rationalization caule (632 accessions), Solanum gourlayi Hawkes (229 processes (NLD037) or loss of material (ARG1347) and accessions) and Solanum sparsipilum (Bitter) Juz. & indicates that the maintenance of clonal plants is a Bukasov (220 accessions) are the largest groups and challenge in terms of cost and plant health status. are mainly held by the USA (USA004, 551 accessions), Russia (RUS001; 119 accessions) and CIP (PER001; 58 S. tuberosum is thought to have evolved from the accessions), respectively. S. acaule (1,491 accessions), S. brevicaule complex (Figure 3) and the three rarer the second largest group, represents S. acaule and domesticated species (i.e. S. juzepczukii, S. ajanhuiri two non-accepted species (Solanum schreiteri and Juz. & Bukasov and S. curtilobum Juz. & Bukasov) Solanum uyunense) according to Hawkes (1990) and is from the S. acaule complex. However, to analyse the preserved in the USA (USA004, 421 accessions), Russia diversity of the landraces present in potato collections, (RUS001;336 accessions) and CIP (PER001; 377 acces- the taxonomic names available from WIEWS (2021) sions). The third largest group (S. stoloniferum; 1,255 were transferred to the taxonomy of Spooner et al. accessions) is represented by four accepted species and (2014) and unknown species names were searched five non-accepted species according to Hawkes (1990) in the Solanaceae database. Overall, 32 taxonomic and the largest collections are in the USA (USA004, names were listed in WIEWS (2021) and were com- 520 accessions) and Russia (RUS001; 271 accessions). bined into 27 available names due to spelling issues, In summary, five potato genebanks (PER001, USA004, of which nine were S. tuberosum, seven S. tuberosum RUS001, DEU159, NLD037) maintain 75% of the col- ‘Andigenum group’, two S. tuberosum ‘Chilotanum lection of wild species and cover 105 of the 107 wild group’ and another two S. juzepczukii (Table Annex species accepted by Spooner et al. (2014). However, A4). Together with S. ajanhuiri Juz. & Bukasov, 16,121 the number of duplicates or unique accessions in these accessions were listed (WIEWS, 2021) as landraces. collections is not clear. Most accessions (9,622 accessions) belong to the S. tuberosum ‘Andigenum group’ and 1,290 accessions Landraces to S. tuberosum ‘Chilotanum group’ (Table 6.5.2.1). About 4,800 S. tuberosum accessions are not further About 18,491 accessions are landraces and represent categorized and may be improved landraces. In addi- 23% of the total (WIEWS (2021) plus survey data), tion, some species were misclassified and are listed and are commonly preserved through clonal plants in the landrace group: i.e. two accessions of S. boliv- in the field or in vitro (Table 6.4.1; Figure 6.5.1). By iense; one accession of Solanum campylacanthum definition, the landrace collections comprise South Hochst. ex A. Rich., one accession of S. candolleanum. American cultivated material, but also selected land- Furthermore, 30 accessions of Solanum x curtilobum, races adapted to specific ecogeographic areas after which are according to Dodds (1962) most likely potatoes were distributed globally, and heirloom S. curtilobum Juz. & Bukasov, and 16 accessions of varieties (see definition Chapter 1). Most landraces the Solanum etuberosum Lindl. outgroup are listed. are maintained in CIP (PER001; 7 species; 4,468 Overall, these results show that most landraces in col- accessions), Russia (RUS001; 11 species following the lections belong to S. tuberosum ‘Andigenum group’, taxonomic treatment of Bukasov (1978); 3,200 acces- which originated between western Venezuela and sions), Germany (DEU159; 7 species; 2,270 accessions), northern Argentina and are di-, tri-, tetra- or hexa- Bolivia (BOL317; 9 species; 1,567 accessions), Colombia ploid. (COL017; 1 species; 1,196 accessions) and the USA (USA004; 5 species; 1,177 accessions), (Figure 6.5.2). Most landraces of S. tuberosum ‘Andigenum group’ Compared to the last survey (van Soest, 2006), Ger- are categorized as S. tuberosum subsp. andigena many (DEU159) increased the collection of landraces (7,845 accessions) and are maintained at CIP (PER001; by +33% (+559 accessions) and the USA (USA004) by 3,308 accessions), Germany (DEU159; 1,215 accessions), +15% (+155 accessions). In Peru, Ecuador, Colombia Bolivia (BOL317; 975 accessions) and the USA (USA004; and Bolivia, the landrace collections increased by 940 accessions) (WIEWS, 2021) (Table Annex A5). +153% (PER867; +475 accessions), +171% (ECU023; Landraces from S. stenotomum subsp. stenotomum +420 accessions), +31% (COL017; +281 accessions) and are maintained at CIP (PER001; 287 accessions), Ger- +12% (BOL317; +167 accessions) (Table 6.4.1). These many (DEU159; 86 accessions) and Peru (PER867; 77 increases are often due to the integration of land- accessions). For the S. tuberosum ‘Chilotanum group’, races obtained from farmers or additional accessions most landraces have been described as S. tuberosum from collecting missions. In other countries, however, subsp. tuberosum and are found in Chile (CHL071; the number of landraces declined, i.e. in the Neth- 492 accessions), Germany (DEU159; 405 accessions) erlands (NLD037) by -442 accessions (-60%), in the and CIP (PER001; 173 accessions). The largest group GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 59 within S. tuberosum belongs to Solanum andigenum 1,395 accessions at POL002 (Figure 6.5.3.1 a). Some (S. tuberosum ssp. andigena, S. tuberosum ‘Andi- institutions are strongly focused on improved vari- genum group’) and is held in Russia (RUS001; 2,701 eties, and more that 50% of their collections consist of accessions). The rare domesticates of S. ajanhuiri, such material, i.e. 100% of POL002 (1,395 accessions) S. curtilobum and S. juzepczukii are mainly kept in in Poland, 100% of IRL036 (700 accessions), and 83% Bolivia and are represented by 64, 80 and 128 acces- of IRL012 (500 accessions) in Ireland, 98% of ROM018 sions, respectively. Considering the small number of (704 accessions) in Romania, 98% of GBR165 (1450 rare domesticates available in the Bolivian genebank, accessions) in UK, 94% of UKR008 (537 accessions) in it is probable that there are gaps in the collections. Ukraine, 69% of IND665 (2,952 accessions) in India, 55% in BLR016 (855 accessions) in Belarus, 51% of Improved varieties CZE027 (1,361 accessions) in Czechia, 51% of EST019 (400 accessions) in Estonia (Figure 6.5.2 and 6.5.3.1). The category of improved varieties consists of These institutes often have close contacts with S. tuberosum varieties that were broadly commercially breeding companies or actively participate in breeding available and often provided by breeding companies programs. for a limited period of time (dependent on consumer preferences and intellectual property protection). This The group of improved varieties has increased consid- group includes 20,735 accessions, representing 25.2% erably (+100%) in the last 15 years. Compared with of the total potato collection (Figure 6.5.1). Five insti- the last survey (van Soest, 2006), more than 10,000 tutions hold 50% of all improved varieties, with 2,952 additional accessions of this type are maintained accessions at IND665, 2,360 accessions in RUS001, 1,943 (Table 6.4.1). In particular, IND665 have increased accessions in DEU159, 1,450 accessions at GBR165 and the number of accessions by 138% (1,712 accessions), Table 6 .5 .2 .1 Total number of landraces maintained in genebanks and listed in the World Information and Early Warning System on Plant Genetic Resources for Food and Agriculture (WIEWS). WIEWS ©FAO 2021, http://www.fao.org/wiews/en/, accessed on 20 Sept. 2021. Species name according to WIEWS (2021) have been transferred to the taxonomy of Spooner et al. (2014) including country of origin, ploidy level. not found = name not present in the https://solanaceaesource.myspecies.info/ database. Accepted by Spooner et al . (2014) Code Country Ploidy Total Solanum ajanhuiri Juz. & Bukasov ahj BOL, PER 2x (2EBN) 98 Solanum curtilobum Juz. & Bukasov cur BOL, PER 5x 121 Solanum juzepczukii Bukasov juz ARG, BOL, PER 3x 191 Solanum tuberosum 4799 Solanum tuberosum ‘Andigenum group’ tub Landraces from W Venezuela South to N Argentina 2x (2EBN), 3x, 4x (4EBN) 9622 Solanum tuberosum ‘Chilotanum group’ tub CHL (Chilean landraces) 4x (4EBN) 1290 Solanum boliviense Dunal in DC. blv ARG, BOL, PER 2x (2EBN) 2 Solanum campylacanthum Hochst. ex A.Rich. 1 Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 1 Solanum x curtilobum (not found) 30 Solanum etuberosum Lindl. 16 Total 16171 (a) Improved variees (b) Breeding lines 3000 10000 * * 2000 * 2000 * 1000 1000 * * 0 0 Figure 6 .5 .3 .1. Top 11 largest potato collections maintaining a) improved varieties and b) breeding lines. Asterisks mark the largest potato collections holders and percentages in each show proportion of the respective collection. 60 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Number of accessions IND665 69 % RUS001 29 % DEU159 31 % GBR165 98 % POL002 100 % CZE027 51 % FRA010 10 % BLR016 54 % ROM018 98 % CHN116 32 % IRL036 100 % FRA010 83 % CHN122 78 % JPN183 78 % CHN116 66 % CZE027 35 % UKR026 38 % CUB005 54 % DEU159 10 % RUS001 7 % ECU023 41 % POL047 97 % RUS001 by 12% (260 accessions), FRA010 by 20% (200 In summary, the institutes that participated in the accessions) and CHN122 by 29% (87 accessions). In con- survey maintain about 69,000 potato accessions and trast, the number of accessions decreased in JPN183 by represent more than 80% of the global potato col- -80% (1,327 accessions), DEU159 by -2% (46 acces- lections in North and Latin America, Europe and Asia. sions) and PER867 by 100% (20 accessions), suggesting In general, the Latin American countries and CIP but that some collections have focused, rationalized or also countries that initiated the first collecting mis- re-structured this part of the collection or may have sions, i.e. Russia, Germany, the Netherlands, UK and lost clonal plants. the USA, maintain comprehensive collections of wild species and landraces. In the last 15 years, the number Breeding lines of accessions of wild species has decreased and the number of accessions of landraces has increased only Breeding lines are the result of intensive crossing marginally, indicating that there are some challenges and selection processes, with the aim of developing in conserving this material. Assessing the composition potato varieties with higher yields and greater tol- of the wild species and landraces collections is ham- erances to stress and diseases. This material may also pered by the different taxonomic classification systems include lines from mapping population panels used applied in the different genebanks. After transfer- for genetic analysis and other research material. In ring the available data into the classification system any case, breeding lines are an important source for from Spooner et al. (2014), it appears that of the 107 further breeding processes and research and comprise known wild species, accessions of only 105 wild species a collection of 22,173 accessions, representing 26.9% can be found in genebanks. However, it is not clear if of all potato accessions worldwide (Figure 6.5.1). The this observation is biased by the simple transforma- country with the highest number of breeding lines is tion. By contrast, the number of improved varieties France (FRA010), which maintains 10,000 accessions and breeding lines in genebanks has increased mas- as clonal plants in vitro and/or in fields, accounting sively, e.g. in France and China, over the last 15 years. for about 50% of the total breeding line collection This increase may reflect the importance of the potato (Table 6.4.1). Other countries with large collections for these countries or new strategic goals for devel- are China with CHN122 (1,600 accessions) and CHN116 oping their agricultural systems. (1,451 accessions) and Japan (JPN183, 1476 accessions). Institutions with a strong focus on breeding lines 6 .6 Challenges of differences in potato (more that 50% of collections) are POL047 with 97% classification systems (422 accessions), FRA010 with 83% (10,000 accessions), PAN147 in Panama with 81% (119 accessions), JPN183 The taxonomic group Solanum section Petota is a very with 78% (1,476 accessions), BGR001 with 78% (336 complex and difficult group shaped by interspecific accessions), CHN122 with 78% (1,600 accessions), hybridization, introgression, polyploidy and the mix of CHN116 with 53% (1,451 accessions) and CUB005 sexual and asexual reproduction. The taxonomic classi- in Cuba with 54% (650 accessions) (Figure 6.5.2 & fication systems have changed considerably over time. 6.5.3.1). The number of breeding lines may indicate The most important changes were that the complex the great importance of potato breeding in these Russian systems, which were based on ploidy levels, countries. morphological and eco-geographic characters and date back to Vavilov (1922); (1935 ), Juzepczuk and The number of breeding lines has developed similarly Bukasov (1929), Lekhnovich (1972) and Bukasov (1978) to the number of improved varieties, increasing by was simplified by Hawkes (1990). He used morpholog- +107% and 13,711 accessions in the last 15 years (van ical parameters, biogeography, crossability and ploidy Soest, 2006). Compared to the last survey, FRA010 levels as the main determinants and incorporated has increased the number of breeding lines by 117% results of (Correll, 1962) and (Ochoa, 1962). However, (5,400 accessions). JPN183 maintained 31 breeding genetic variation in ex situ collections may not be lines in 2005 and increased by 1,445 accessions, comprehensively explained by morphological char- CHN122 by 300% (1,200 accessions) and RUS001 by acters (Tanksley and McCouch, 1997) and conversely, 200% (400 accessions). (Table 6.4.1). However, com- genetic markers may not predict specific traits either. parable to the improved varieties, some institutions Therefore, David Spooner and collaborators have reduced the number of breeding lines, in particular worked intensively on an integrative taxonomy which PER001 by -99% (3,139 accessions), DEU159 by -20% aimed to combine evidence from natural history, (207 accessions), BOL317 by -100% (300 accessions) botany, biogeography, ecology and genetics (Spooner and USA004 by -30% (163 accessions). Again, it is likely et al., 2004; Spooner et al., 2007; Ovchinnikova et that the decline in breeding lines is due to rationaliza- al., 2011; Spooner et al., 2014; Spooner et al., 2016; tion or re-structuring of the collection or that clonal Spooner et al., 2019). Their goal was to develop a plants have been lost. complementary perspective that includes a predictive GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 61 classification, proposing provisional taxonomic groups type from the USA are now called S. stoloniferum, based on hypotheses of phylogenetic relationships although none of them look like the classic stolon- among species that reflect the evolutionary history of iferum known from Mexico. potatoes, and pending more data to elucidate inter- 2. A new species name may now represent a very relationships. In addition, this classification aimed to minor fraction of the accessions. For example, be useful for conservation and breeding (personal approxiately 20 accessions of the original Solanum communication Iris Edith Peralta, 2021). boliviense had been in the US collection before Spooner et al. (2014) lumped them with approxi- Extensive taxonomic work was conducted on 7,641 mately 200 additional accessions of Solanum astleyi specimens in 74 herbaria, plus field work, experi- Hawkes & Hjert., S. megistacrolobum, Solanum mental trials, and the evaluation of quantitative, sanctae-rosae Hawkes and Solanum toralapanum qualitative and molecular characters (Spooner et al., Cárdenas & Hawkes in this group. As a result, the 2014). As a result, the 228 wild potato species, seven identities of many S. megistacrolobum accessions cultivated species and 19 taxonomic series recognized have disappeared and been replaced with S. boliv- by Hawkes (1990) were combined into 107 wild and iense, which was originally only 10% of the acces- four cultivated species (Spooner et al., 2014). Nowa- sions. This is because accessions are not synoni- days, most genebanks still apply the Hawkes (1990) mized according to the name which has any logical taxonomy, VIR (RUS001) applies the classification dominance in numbers of accessions in genebanks system according to Bukasov (1978), while those which or size of geographic natural distribution, but only use GRIN, such as the US potato genebank (USA004), on the historic precidence of the taxonomic name. apply the classification system of Spooner et al. (2014). 3. The S. tuberosum ‘Andigenum group’ now com- Unfortunately, the three classification systems used prises landraces with different ploidy levels. But can be problematic for users of the collections and breeders are often quite interested in knowing if pose challenges for database searches, ‘gap analysis’ stocks will cross readily with their diploid or tetra- and the identification of duplicates. Therefore, the ploid material. So, it is an extra step to download a community needs to develop a way to combine the list of available andigenum accessions as a jumble benefits of the two taxonomic classification systems. of ploidies, then use a secondary ploidy datafield to sort them to the previously familiar diploid phureja Although both systems have a rational and well-de- or tetraploid andigena accessions. veloped basis, the classification according to Hawkes (1990) is very useful in managing ex situ collections The overall proposals towards a harmonization of due its precise species characterization and detailed taxonomy includes and comprehensive morphological descriptions. 1 . Subdivision of large groups . Large species groups However, the revision by Spooner et al. (2014) is of Spooner et al. (2014) may need to be sub-di- considered an advance in the field (Ellis et al., 2020) as vided based on their genetic diversity because morphological descriptors are qualitative but do not identification of gaps is more likely in smaller necessarily show the underlying variation in diverse groups. Where appropriate, Hawkes (1990) or collections, e.g. the large phenotypic diversity in tuber other classification for grouping may be used for traits does not reflect the allelic diversity for disease sub-division. resistance and stress tolerance (Jansky et al., 2015). As 2 . Predictive taxonomy should be considered and a consequence of DNA marker analysis, many species names to be associated with traits; when grouping categorized by their phenotype have been merged is necessary, sub-groups need to be identified by because they could not be clearly distinguished in modern technologies and may be predictive for genetic analysis. While the lumping of species elimi- specific traits. nated intermediates, it resulted in specific problems 3 . Intermediate forms might be given a standard in the management of genebank collections. Some of name other than “unknown” or “spp.” so that these issues can particularly create confusion for germ- users of the germplasm have some idea about their plasm users and were communicated by John Bamberg background. (curator of the US potato collection, USA004, 2022): 4 . The Intergenebank Potato Database (Huamán et 1. A new lumped species often does still have empir- al., 2000) already matches wild species accessions ically distinguishable “old” species types within. between eight genebanks based on collector/acces- Solanum fendleri A. Gray, S. stoloniferum, and sion numbers or digital object identifiers (DOI). Solanum polytrichon Rydb., for example, can be The database should be revised and linked to or clearly distinguished by morphological charac- integrated into other platforms, i.e. Genesys and ters. By combining them into S. stoloniferum, the EURISCO. usefullness of the identities of these types has been 5 . Genebank databases should also include refer- lost, sometimes in a misleading way. For example, ences to the taxonomic framework used. Changes all of the hundreds of collections of the S. fendleri to the taxonomic description should be stored in 62 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO the database, including infraspecific categories. cies are required because they are threatened by 6 . Identification of taxonomic preferences of users, habitat modifications or introduction of invasive genebank curators and taxonomists. species 7 . Comprehensive DNA marker sequencing would 9 . Digitization of herbaria . Support the work of provide additional information about accessions taxonomist through digitization and expansion of and support taxonomists, genebank curators, and herbaria. users. Agreements on standardized marker systems 10 . Evaluation and characterization data will support and establishment of user-friendly analysis plat- the work of taxonomists and help to identify forms would be required. useful accessions for users. Consider establishing 8 . More information is needed about natural popula- core sets for detailed characterization tions and hybrids, more collections of wild spe- GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 63 7 POTATO GERMPLASM MAINTENANCE 7 .1 Ex situ maintenance of potato and conserve their germplasm in the field, usually in locations that are less susceptible for pests and The conservation of potato accessions is varied and diseases. CIP (PER001) grows out and maintains tubers depends on the type of material (Figure 7.1.1). Acces- from the landrace collection in a 3 ha field in Huan- sions of wild species are collected as populations and cayo, Peru at an altitude of 3200 m (Huaman et al., are mostly preserved as orthodox seeds in cold storage 2000). The US potato genebank (USA004) uses fields at facilities. For landraces and improved varieties, the the Hancock Agricultural Research Station, the central specific allele combination of each genotype needs potato production area in Wisconsin (Bamberg, 2021). to be maintained as a clonal accession in the field, in The potato field collection of IPK (DEU159) is located vitro or in cryopreservation (in cryo). The following at the Groß Lüsewitz station (GLKS) in Mecklenburg data summarize the conservation practices of 32 col- Vorpommern and VIR (RUS001) uses experimental lections, comprising more than 80% of potato germ- stations in different geographic areas such Saint plasm and located in Asia (3 collections), Europe (17 Petersburg, Murmansk, Moscow, Tambov region, and collections), Latin America (8), North America (2 collec- Krasnodar (Kiru et al., 2007). Usually, up to 10 tubers tions), plus the International Center CIP (PER001). are planted in the field and the emerging plants are described and characterized. A list of descriptors (see 7 .2 Field maintenance and short-term chapter 4.2) has been elaborated by FAO and IPGRI warehouse storage of seed potato (Alercia et al., 2018) and between different genebanks (Huaman et al., 1977; Gomez, 2000) to exchange ger- Field maintenance is the traditional approach to mplasm information and provide breeders with a pre- maintaining clonal plant genetic resources. The ben- liminary set of characterization and evaluation data. efit is that the accessions are easily accessible, can be described and images and voucher specimen can be Storage of tubers is essential for further tuber evalua- prepared easily (Panis et al., 2020). Therefore, most or tion, characterization and distribution, and to bridge even all collections have the potential to reproduce the gap between growing seasons. To avoid quality 64 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Cryopreservation at IPK genebank, Gatersleben, Germany. Photo: Lynn Maine/IPK losses during storage due to mobilization of starch as carbohydrates and organic acids (Viola et al., 2007) and proteins (Sonnewald and Sonnewald, 2014), tuber dormancy is essential and can be partly controlled by In general, the application of controlled tuber storage environmental conditions. In this state, the buds that depends on the country and the intended use, e.g. contain the meristems show no visible signs of growth, tubers for the processing market require higher tem- whereas the remaining part is still metabolically active peratures between 8–13°C to maintain frying quality yet at a reduced rate (Viola et al., 2007; Sonnewald while temperatures below 7°C can be applied for and Sonnewald, 2014). The most important post-har- potatoes for the fresh market or for storing tuber as vest environmental factor to affect tuber dormancy propagules for the next planting season. Depending (ecodormancy) is temperature, which is inversely on the variety and the location of production, exces- related to the duration of dormancy and optimally sively low temperatures can cause the accumulation of lies in a range of 3–20°C. In addition, humidity control reducing sugars and lead to ‘cold-induced sweetening’ as well as controlled gas composition help maintain (Alamar et al., 2017). In countries where warehouse dormancy (Wiltshire and Cobb, 1996). External phys- systems are poorly developed, tubers are often stored iological factors such as the application of chlorpro- in wooden boxes with air-circulation. However, pham (CIPC) or other chemical alternatives (Alamar these can promote the spread of fungal diseases. et al., 2017) stimulate paradormancy (Suttle, 2007). For example, monitoring airborne elements showed In addition, the length of tuber dormancy is under elevated amounts of fungal spores from Cladosporium genetic control and involves the interaction of plant followed by Aspergillus/Penicillium, Helminthosporium growth regulators such as abscisic acid (ABA), auxins, and Alternaria during potato storage in warehouses cytokinins (CKs), gibberellins (GAs), ethylene, and without control. In storage systems with cooling con- strigolactones (SLs), as well as other compounds such ditions, the most abundant fungal spores were from Greenhouse / Tuber storage 16 -25°C or 3-6°C, 60 – 85% wooden or plasc trays ARG1347 (20%) Seed storage BEL023 (100%) In-vitro storage BGR001 (62%) Ac ve storage IV1: 17-20°C ,35 – 85% BRA020 (83%) 4°C, 50-65%, ARG1347 (100%) CAN064 (100% Alu/paper bags BGR001 (10%) CHL071 (100%) ARG1347 (100%) BRA020 (53%) CHN122 (80%) CAN064 (100%) CAN064 (100%) COL017 (99%) COL017 (90%) CHN122 (20%) CUB005 (90%) CUB005 (10%) CUB005 (10%) DEU159 (59%) DEU159 (100%) COL017 (90%) ECU023 (100%) GBR251 (68 %) CZE027 (100%) ESP016 (30%) GTM001 (100 %) DEU159 (45%) Base storage FRA010 (80%) IV2: 2-10°C ,40– 95% ESP016 (100%) -10 - -20°C, GTM001 (100%) ARG1347 EST019 (100%) 20-70%, Alu bags IND665 (10%) COL017 FRA010 (40%) COL017 (25 %) JPN183 (90%) CZE027 IND665 (100%) Backup storage ECU023 (100 %) LVA006 (100%) DEU159 Backup storage Backup storage IRL036 (100%) CAN064 (CAN, 100%) GBR251(100 %) PER001 (35%) ESP016 ARG1347 (ARG 50%) BEL023 (BEL, 10%) LVA006 (70%) CHN116 (CHN122*, 10%) NLD037 (100 %) PER860 (100%) EST019 CAN064 (CAN 100%) CAN064 (CAN, 100%) PER001 (98%) FRA010 (FRA, 0.5%) PER001 (94 %) ROM007 (100%) FRA010 DEU159 (SGSV 100%) IRL036 (UK, 100%) ROM007 (60%) IND665 (IND, 100%) RUS001 (30 %) RUS001 (75%) IND665 GBR251 (SGSV 100%); PER001 (PER, 100%) RUS001 (8%) PER001 (BRA, 98%) USA004 (100 %) LVA006 GBR251 (NLD 95%) SWE054 (100%) PER001 (PER, 100%) PER001 NLD037 (SGSV 90%) PER001 (DEU159*, 7%) ROM007 NLD037 (GBR251*) RUS001 (CUB*, 100%) SWE054 PER001 (PER 100%) Cryopreserva on SWE054 (SWE, 100%) RUS001 (CUB 30%) PVS2, PVS3, DMSO, SVN019 (CZE027, 80%) USA004 (USA 100%) LN or vapour USA004 (USA, 100%) CZE027 (4 %) CHN122 (~1%) DEU159 (27 %) FRA010 (~1 %) JPN183 (32 %) PER001 (68 %) RUS001 (~1%) Backup storage DEU159 (DEU, 27 %) Figure 7 .1 .1 . Potato ex situ storage approaches applied by 32 potato collection holders participating in the survey. Percentages in brackets describes the estimated proportion of the collection maintained under each storage condition. For the backup repositories, the country and percentage of collections located outside the respective institute are indicated in brackets. *Numbers provided by the institution where the backup repository is located. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 65 M. Nagel (2022) Aspergillus/Penicillium, Cladosporium, Fusarium (Meno When plants are introduced into in vitro culture, et al., 2021). Interestingly, the production of potato combinations of chemo-, and thermotherapy fol- tubers from true potato seeds prolonged significantly lowed my meristem isolation ensure virus-free stocks the period of tuber dormancy, and also the days to (Keller et al., 2006; Keller et al., 2012). However, the tuber shrinkage, compared to plants grown from US potato collection is screened every five years for tubers. If this is a viable alternative, this approach Potato Virus A (PVA), PVM, PVS, PVX, PVY, Potato has important benefits in countries which cannot Leaf Role Virus (PLRV), Potato Spindle Tuber Viroid apply refrigeration storage, passive cooled water (PSTVd), and bacteria such as Clavibacter sepedonicus or sprouting inhibitors (Roy et al., 2006). However, causing potato ring rot (Bamberg et al., 2016). For CIP in potato collections, where genotypes need to be (PER001), the relevant viruses for import/export are maintained, tubers are commonly stored for extended the Andean potato latent virus (APLV), Andean potato short-term periods, at low temperatures and higher mild mosaic virus (APMV), the Arracacha virus B, Oca humidities. strain (AVB-O), Potato Virus T (PVT), PVS, PVX, PVY, PLRV and PSTVd (Ellis et al., 2020). At IPK (DEU159), Most collections maintain and reproduce between the collections are regularly tested for the common 20–100% of their material in the field or in the green- virus strains PVA, PLRV, PVM, PVS, PVX, and PVY. house (survey data). In the Northern Hemisphere, Furthermore, accessions are screened for the absence tubers are planted in spring, grown and characterized of PSTVd and bacterial quarantine diseases caused by during the year, harvested at the end of summer and Clavibacter sepedonicus and Ralstonia solanacearum stored until the next growing season. For CHL071, upon entry to the collections. Entries of Southern COL017, ECU023, GTM001, PER860 and CUB005, more American origin are additionally screened for Andean than 90% of the collection is preserved in the field, Potato Latent Virus (APLV-Col, APLV-Col 2, APLV-Hu), while other collections keep a smaller proportion for Andean Potato Mottle Virus (APMoV-B, APMoV-H), national distribution, characterization and evaluation Potato Black Ringspot Virus (PBRSV), AVB-O, PVT, in the field. These include DEU159, ESP016, IND665 Potato Virus V (PVV) and Potato Yellowing Virus and PER001, with between 10–60% field reproduc- (PYV). For distribution, test certificates for the absence tion. For storage, tubers are stocked in plastic boxes of Clavibacter, Ralstonia and PSTVd not older than at low temperatures between 3–6°C, and 60% rela- three years have to be provided (personal communica- tive humidity (RH). Storage at higher temperature tion Klaus J. Dehmer 2021). Although plants are main- in wooden boxes is often applied when cold storage tained under sterile conditions and screened regularly facilities are not available, e.g. GTM001. To avoid the for potential diseases, growth retardation, cellular risk of losing accessions during the year, clonal potato ageing and endophytic contaminations can affect the collections in the field are often backed up by in vitro viability of in vitro plant and thus their survival (Panis slow growth storage. et al., 2020). In combination with potential infections of mites and/or other insects, the collections can be 7 .3 Medium-term storage through in severely compromised. vitro slow-growth maintenance Of the 32 survey participants, 21 collections are fully Clonal in vitro plants can be kept disease-free under or partly maintained in slow growth storage (survey sterile conditions for a longer period under slow- data). Between 90–100% of the collection are main- growth storage conditions. To reduce metabolic tained in vitro by ARG1347, CAN064, COL017, CZE027, activity and thus plant growth, lower temperatures ESP016, EST019, IND665, IRL036, PER001 and SWE054. and lower light intensities are commonly applied. The Other institutions, such as BRA020, DEU159, FRA010, procedures, parameters and media are very spe- LVA006 and ROM007, store between 40–90% in vitro, cies and institute specific. For slow-growth storage and BGR001, CHN122 and CUB005 between 10–20%. of S. tuberosum at IPK (DEU159), a combination of In the collections where there is a lower proportion of warm (20°C for 2–3 months) and cold phases (9°C accessions in in vitro storage, the remaining portion for 2–4 months, low light intensity) is used to induce of the collection is either maintained as true potato microtubers, followed by cold storage (4°C, low light seeds or as clonal plants in the field. However, only 12 intensity) for 16–18 months (Keller et al., 2006). At participants indicated that they have cold rooms avail- USA004, plants are sub-cultured, grown at 20–22°C for able. Therefore, nine respondents may not be able 2 weeks and stored at 8–10°C and low light intensity to induce and maintain shoot cultures or microtubers for 12–18 months (Bamberg et al., 2016). The growth at lower temperatures, and therefore the intervals medium contains MS medium supplemented with 6% for sub-culturing are shorter and the workload much sucrose and in some cases sorbitol (Sarkar et al., 2001). higher. Notably, curators from Latin America reported However, large variations exist between different that they rely on older equipment and technologies institutions. and have no resources to replace them. If the equip- ment breaks down, there is the risk of losing the 66 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO entire in vitro collection. This partly explains the 30% for cryopreservation, which involves reducing water decline in the ARG1347 landrace collection, which activity to a minimum and rapid cooling with liquid should be considered as severe risk. nitrogen (LN), such that the cytoplasm vitrifies. In this state, the molecular mobility of the water molecules Only nine survey participants have the possibility to is reduced and metabolic processes are greatly slowed back-up at least part of their collection at another down, allowing long-term survival of the biological site. Among these, CAN064, IND665, PER001, SWE054, material. Depending on the species, organ and the SVN019 and USA004 have between 80–100% of technical background and experiences of the labora- their collections safely duplicated. For example, CIP tory, protocols may vary and the individual steps differ (PER001) backs up its in vitro collection at a distant (Panis et al., 2020). site within Peru (Huancayo) as well as internation- ally at BRA020 in Brazil. With other genebanks, it is Sakai (1960) was the first to succeed in ensuring the common practice to back-up, i.e. minitubers at 5°C. survival of plants at ultra-low temperature using Overall, only a part of the world’s in vitro potato dormant bud cryopreservation. Over the years, other collection is securely maintained and backed-up and approaches, such as slow freezing (also known as significant infrastructure improvements are needed, 2-step cooling), encapsulation-dehydration and in particular in Latin American countries, for in tissue dimethylsulfoxide (DMSO) droplet freezing were culture and cold storage facilities. developed. However, the introduction of plant vit- rification solutions (PVS), including PVS2 composed 7 .4 Long-term storage via cryopreserva- of 30% glycerol, 15% ethylene glycol, 15% DMSO tion and sucrose (Sakai et al., 1990), and PVS3, composed of 50% glycerol and 50% sucrose (Nishizawa et al., Although in vitro preservation offers some benefits 1993), have opened a range of possibilities for rapid because the plants are available immediately and cryopreservation of shoot tips with high survival rates. throughout the year for research and distribution, The main challenge is to adapt the different species cryopreservation is the only approach for secure long- and even sub-species groups to these methods, which term storage of clonal plant genetic resources collec- may require changes in pre-culture and cryoprotection tion and thus minimizes the risk of loss (Panis et al., treatments as well as in the composition of solutions 2020). Most methods use the process of vitrification and media. Pre-culture over night (if applied) Shoot p Dehydra on/ prepara on Cryoprotec on using PVS2, PVS3 Cold treatment PVS2/ PVS3, V Cryo-plate at 4 °C, dark Droplet Vitrifica on (if applied) LN treatment Plant propaga on at 20°C at - 196°C In vitro storage at 20/ 10/ 4°C M. Nagel (2022) Thawing, Washing & Recovery Field maintenance, tuber storage Long-term cryopreserva on Figure 7 .4 .1 . Principal procedure during PVS2, PVS3, V Cryo-plate droplet vitrification cryopreservation. PVS, plant vitrification solution; LN, liquid nitrogen GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 67 The number of potato landraces cryopreserved has targeted, including potato, and hence this initiative increased considerably in the last 15 years (van Soest, could play a role in securely backing up all potato 2006). Landraces and improved varieties have been genetic resources collections. cryopreserved mainly at CIP (PER001), IPK (DEU159) and NARO (JPN183) by using PVS2, PVS3 and the V 7 .5 Storage of orthodox potato seed cryo-plate approach, respectively. All approaches involve the propagation and cold acclimation of The majority of plants studied on Earth produce the in vitro donor plants, the excision of shoot tips orthodox seeds that are desiccation tolerant and stor- followed by a loading and cryoprotectant step using able at low temperatures over long periods of time. In PVS2, PVS3 or a cryo-plate and rapid immersion in LN contrast, a smaller amount of angiosperms and gym- (Figure 7.4.1). By using PVS2 droplet vitrification, CIP nosperms produce ‘recalcitrant’ seeds, which are desic- (PER001) has cryopreserved more than 4,000 cultivated cation- and chilling sensitive and have short life spans potato accessions over the last 20 years (Vollmer et al., (Kew, 2018). As orthodox seeds have the ability to sur- 2021) (personal communications Rainer Vollmer, 2021). vive extraordinary long periods of storage, e.g. seeds IPK (DEU159) initially used DMSO droplet freezing of Nelumbo nucifera Gaertn. found in north-eastern (Kaczmarczyk et al., 2011) but has since changed China germinated after about 1,300 years (Shen-Miller to PVS3 droplet vitrification and has cryopreserved et al., 1995), they are ideal for the preservation of about 1,900 accessions located at IPK and in a backup plant genetic resources. Most Solanum species of the storage facility at Leibniz-DSMZ in Braunschweig, Petota group produce fertile orthodox seeds. How- Germany (Köpnick et al., 2018; Panis et al., 2020; ever, due to high heterozygosity, seeds cannot be Senula and Nagel, 2021). NARO has cryopreserved used to store the allele combination of a particular more than 640 accessions (personal communications genotype, but are very suitable for the conservation Shin-ichi Yamamoto, 2022) using the V-cryo plate with of individual genes or haplotypes or seed populations PVS2 (Yamamoto et al., 2015). Other institutes, such as of wild species. Unfortunately, when summarizing the CZE027, CHN122, FRA010 and RUS001 [for RUS001 see findings on storability of S. tuberosum seeds, it must Gavrilenko et al. (2019a); Efremova et al. (2021)] have be noted that the literature lacks current research started to cryopreserve their material. However, due results, and the terminology is confusing because to the increasing number of clonal plants in in vitro small potato tubers are also considered as “seeds” for collections and field genebanks, combined with an planting. Therefore, orthodox seeds of potato plants increasing workload and limited funding for potato are also called ‘true potato seed’ or TPS. genebanks, specifically in Latin America, the risk of losing unique accessions is increasing. Cryopreserva- Over the last decades, ‘Genebank Standards for Plant tion can ensure a long-term conservation at minimum Genetic Resources for Food and Agriculture’ have cost. Therefore, the Global Plant Cryopreservation Ini- been developed and repeatedly revised. A group tiative, which is currently proposed (personal commu- of experts agreed on the ABS (Active-Base-Security) nication David Ellis, 2022), is urgently needed to help system and proposed to dry orthodox seeds between securely back up potato collections. 5–20°C and 10–25% RH and to store only material with an initial germination of >85%. Seeds in (A) active The Global Plant Cryopreservation Initiative is tar- storage are held at 5–10°C and 15% RH for about geting the secure, long-term cryopreservation of at 30 years, from which distribution are made. Seeds in risk clonal and recalcitrant seed crop genetic resources (B) long-term base storage, and (S) security back-up collection, including potato. This initiative is a fol- storage are often packed in airtight containers and low-up to the Feasibility Study for a Safety Back-up stored between -20--15°C, under which the seed Cryopreservation Facility (Acker et al., 2017), which should remain in high quality for more than 30 years. concluded that there was an urgent need for a global In the case of (S), the cold storage rooms should be at effort to operationalize cryopreservation as a long- a geographically far location from (B), preferably one term conservation strategy for genetic resources back-up nationally and another internationally, such collections which cannot be backed up at the Svalbard as the SGSV. Additionally, to ensure that accessions are Global Seed Vault (SGSV). The initiative proposes the rejuvenated before viability drops below 85% of the establishment of regional centers of cryo excellence initial viability, an active viability monitoring program that can provide cryopreservation training, cryo should be implemented (FAO, 2014). Since 2008, SGSV back-up facilities, operational cryopreservation of has stored a backups of many of the major collections genetic resources collections and establishment of a of plant genetic diversity and more than one million plant cryopreservation community of practice. The samples from more than 89 genebanks have been intent is to raise awareness of plant conservation and deposited so far. facilitate the development of expertise, protocols, guidelines, international standards and networks. The true potato seeds of Solanum wild species are Genetic resources collections of 10 crops are initially considered to be very long-lived. Towill (1983) showed 68 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO that 92% of the S. demissum seeds, 100% of Solanum Storage of true potato seed is usually favored for hjertingii Hawkes seeds and more than 96% of the accessions of wild species, but occasionally land- seeds of the S. tuberosum groups Andigenum and races are also maintained as seed, especially in Latin Phureja germinated after more than 26 years of American countries. The survey results show that 12 storage at 1–3°C and 5% seed moisture content. In participants (ARG1347, CAN064, COL017, CUB005, contrast, a more detailed study of true potato seeds DEU159, ECU023, GBR251, GTM001, NLD037, PER001, from cultivated potato measured germinability of RUS001, USA004) preserve true potato seeds. Unfortu- 159 S. tuberosum accessions stored at the USDA nately, the survey could not fully clarify whether true National Center for Genetic Resources Preservation, potato seeds belong to wild potato species or culti- the same center which Towill worked at. These data vated potato and whether the ABS system is applied measured a decline by an average of 57% within 24 in the different genebanks. The responses indicate years of storage at -18°C and undefined “low seed that seven genebanks actively store their material moisture content”, resulting in an estimated half-vi- in (A) in aluminum or paper bags at 4° and 50–65% ability period (P50) of 22 years (Walters et al., 2005). RH. Only seven collections holders have the option of Seeds stored under ambient storage conditions at an storing (B) samples in sealed aluminum bags at various experimental station in France had a P50 of 9.4 years temperature between -10--20°C, and eight genebanks (Priestley et al., 1985). These results led to the consid- have backed up at least 50% of their collections at the eration that S. tuberosum seeds might have a ‘medium SGSV or elsewhere. To apply the ‘Genebank Standards short’ longevity (Walters et al., 2005). Overall, there for Plant Genetic Resources for Food and Agriculture’, are few reports on germination after long-term most genebanks need to improve their facilities (e.g. storage or species-specific information. Therefore, by additional installation of cold storage and drying further research is needed to draw comprehensive facilities), equipment (e.g. vacuum sealers) and con- conclusions about the seed storage behaviour of all sumables (e.g. aluminum foil bags). wild as well as cultivated potato seed. 7 .6 Challenges of potato germplasm Most true potato seeds, from both wild and cultivated maintenance and steps to improve species, exhibit physiological dormancy which can be broken either by a treatment of GA (2000 ppm GA3), The application of best storage and maintenance by alternating temperatures using 21°C and 6°C for practice is the foundation for the long-term conserva- 8 and 16 h, respectively (Bamberg, 2018), or by high tion of potato genetic resources to maintain the full storage temperatures and elevated moisture con- genetic potential for future generations. High priori- tents (Pallais, 1995; Pallais et al., 1996). For example, ties should be given to storage conditions and han- freshly harvested true potato seeds of the Peruvian dling to ensure a long-term survival of this valuable variety ‘Ccompis’ were dried to 3.4, 4.2, 5.1, 6.1, and material. 7.3% moisture content (dry weight basis) and hermet- ically stored at 15, 30, and 45°C for 6 months. Seed Field maintenance . Most national genebanks in Latin dormancy was released, and germination increased American countries, but also genebanks in Europe, during 4 months of storage at 3% and, more rapidly, maintain up to 100% of their collections in the field, at 5% moisture content and 45°C. When seeds were where the material is exposed to severe environ- stored at a moisture content of 7% and 45°C, deterio- mental risks. The chances of genetic drift and also loss rative processes occurred and germination decreased are high. In addition, optimum tuber storage facilities within the first month and was lost after 3 months with controlled cold rooms and cleanable plastic trays (Pallais, 1995). In general, germination depends on are not always available. High priority should be given seed quality, which is influenced by many other fac- to adequate conditions for tuber storage and optimal tors, including nitrogen levels during seed production field management. It is highly recommended to dupli- (Pallais and Espinola, 1992) and the position in the cate and/or back up field collections in vitro or in cryo inflorescence from which seeds originate. Larger seeds both on site and in a geographically distinct location. with higher germination and better seedling growth have been obtained from late-harvested primary inflo- In vitro slow growth (medium-term) storage . Overall, rescences (Almekinders and Wiersema, 1991). Beside 21 genebanks fully or partially conserve the material the reproduction of wild species, seed quality and dor- through slow growth storage. Of those, only 12 gen- mancy breaking are of great relevance in the produc- ebanks reported having cold storage facilities avail- tion of potato tubers from true potato seeds, such as able and only nine have backed up their collections in the production of an inbred hybrid potato system. elsewhere. Priorities include research to improve the Further studies and developments are necessary in methodology of slow growth storage, additional cold the future to produce large quantities of high-quality storage facilities, and an in vitro back up system for seeds with lower dormancy level. safety duplicates. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 69 Cryopreservation . Cryopreservation enables the Seed storage . Although the storage of orthodox long-term conservation of clonal potato accessions, seeds has been extensively studied, information on and possibly true potato seeds, at minimal costs. the species of the Solanum group Petota is very rare. However, currently only three genebanks (PER001, The long-term viability of seed of cultivated and wild DEU159, JPN183) are intensively cryopreserving their species and their optimum storage conditions have collections. To avoid the loss of unique material in the not been sufficiently studied, and as indicated earlier field or in vitro, further cryopreservation efforts are there is good evidence that true potato seeds and needed. In parallel, standards for ‘best practice’ have seed from potato wild relatives may not store as long to be established and research on optimum cryo- as originally thought. Although cryopreservation preservation conditions, fundamental processes, and of true potato seeds is an option, this has not been the effects of long-term cryopreservation have to be researched. Further, not all genebanks are currently intensified. If material is stored only in cryo, an Active- capable of adhering to the Genebank Standards, Base-Safety (ABS) system should also be considered including the ABS system. Therefore, there is an involving different storage sites and secure back up urgent need to: 1) back up high-quality seeds under storage. The Global Plant Cryopreservation Initiative dry conditions in aluminum foil bags and low tem- focuses on all these aspects and needs to be supported peratures at different sites, including the SGSV, 2) pro- to ensure a long-term conservation of potato. vide infrastructure to those genebanks which do not have cold storage capacities, and 3) initiate research into long-term seed storage behaviour and cryopreser- vation of true potato seeds. 70 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO 8 MANAGEMENT OF THE COLLECTIONS 8 .1 Establishment of procedures and Protocols protocols available not available Storage & maintenance Detailed written procedures and protocols are essen- tial for the safe and effective transfer and exchange Germina on tests 0.5 to 25 y of experience and knowledge between staff and Viability tests annually, con nuously genebanks, and for assuring the best possible storage, Characteriza on regeneration and distribution of high-quality seed Regenera on and clonal material. Out of 32 genebanks, 26 reported having established protocols and documents for fun- Health of germplasm damental processes of ‘storage and maintenance’ of Health tests annually to triannially accessions as well for ‘characterization’ (Figure 8.1.1). Twenty-four genebanks have written procedures Documenta on for ‘regeneration’ available and 21 genebanks have Distribu on procedures for ‘health of germplasm’ and ‘documen- tation’. Protocols for ‘distribution’, ‘safety duplica- Safety duplica on tion’, ‘acquisition’ are only reported by 18, 17 and Acquision 16 genebanks, respectively, and only 16 genebanks can provide a copy of their protocols. However, half of participants (15 genebanks) follow protocols for Protocols freely available six to eight functions, and of those, nine genebanks (DEU159, ESP016, EST019, NLD037, PER001, RUS001, 0 10 20 30 SVN019, SWE054, USA004) have protocols for all Number of genebanks functions. Two genebanks (DEU159, NLD037) are Figure 8 .1 .1 . Availability of germination, viability and health ISO 9001/2015 certified. In the last survey (van Soest, tests protocols and written procedures in genebanks responding 2006), half of the participants reported keeping pro- to the survey (see chapter 6.3). Green, protocols available and test performed; black, protocols not available; grey, no tocols for two to six genebank functions, indicating information provided. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 71 Maintenance of potato landrace and other Andean crops at the Parque de la Papa in Cusco. Photo: Manuela Nagel/ IPK an increased awareness of the importance of written ECU023, GTM001, and 650 accessions (25%) at PER001 procedures. In summary, fundamental aspect of potato need seed regeneration. In Europe and Asia, only 20 germplasm storage and maintenance are documented accessions would seem to require regeneration. In the by the majority of genebanks. However, for at least last survey (van Soest, 2006), more than 3,600 acces- one function, most genebanks cannot provide proto- sions were classified as in urgent need of regenera- cols. To ensure high quality seed and clonal material, tion. Although the recent survey indicates an improve- and adequate guidance for technical staff, it is highly ment, the collections of wild species in RUS001, recommended that all procedures are fully and clearly NLD037, GBR251, CZE027 have decreased significantly documented. and it should be assumed that the remaining mate- rial will likely lose viability over time. In any case, van 8 .2 Regeneration Soest (2006) stated that although three holders used 20–30 plants for regeneration of seed, most gene- Most conservation approaches require frequent banks used between 10–20 plants and two genebanks regeneration, but at different intervals. In general, used fewer than 10 plants for seed multiplication. the frequency of regeneration is as follows: field Unfortunately, this aspect of seed multiplication was maintenance > slow growth storage > seed storage > not included in the recent survey. However, the situ- cryopreservation. Field maintenance usually requires ation is not expected to be very different. If a small annual and slow growth storage an annual/biennial number of plants is used for seed multiplication, chal- regeneration. Depending on seed quality, quantity lenges due to genetic drift are higher, increasing the and storage conditions, seed regeneration may be likelihood of alleles being lost. Additionally, self-in- considered after decades. Routine monitoring of compatibility can lead to problems with seed sterility potato in cryostorage is being done by CIP (PER001) during reproduction. and DEU159. However, it is too early to say when cryopreserved material will need to be renewed. To Landraces . Of the total collection of 15,744 landraces date, there has been no decline observed but it will be accessions, about 1,900 accessions (12.1%) need to be prudent for future generations to continue to monitor regenerated. Most accessions are maintained as clonal the material to ensure it is renewed prior to a decline plants in in vitro slow growth storage or in the field. in viability. In this respect, cryopreserved material can In Latin America, field maintenance predominates, be viewed as very analogous to long-term orthodox and about 1,600 accessions, 53.0% of the Latin Amer- seed banks where routine monitoring is needed. The ican landrace collections, specifically COL017, ECU023, difference with the cryopreserved material is that GTM001, PER860, need to be regenerated. Several “extra” vials of randomly selected accessions may Latin American genebanks reported sub-optimum need to be cryopreserved so that material is available storage condition due to defective and missing cold, to future generations for monitoring viability (per- tuber and in vitro storage facilities. As a consequence, sonal communication David Ellis and Manuela Nagel, a high percentage of material requires urgent regen- 2022). eration. In Europe, three genebanks (BEL023, BGR001, GBR251) have predominantly field maintenance, with Wild species . The participants of the survey reported 4.6% of the collections (320 accessions) requiring that overall about 1,260 accessions (8.3%) of the urgent regeneration. In comparison to the previous 16,550 accessions maintained require urgent regenera- survey, the number of accessions of landraces that tion (Figure 8.2.1). As most wild species are conserved need urgent regeneration has decreased from 6,000 as seeds, about 560 accessions (29.6%) of the collec- (van Soest, 2006) to 1,900. For reproduction in the tions in Latin America, specifically ARG1347, CUB005, field, 15–30 tubers are used (van Soest, 2006), while Total Asia Europe Interna onal La n America Wild species Landraces Breeding lines Improved variees Others 0 25 50 75 0 25 50 75 100 0 25 50 75 100 0 25 50 75 100 0 25 50 75 100 Percentage of the collec on Figure 8 .2 .1 . Percentage of accessions of wild species, landraces, improved varieties and breeding lines which requires urgent regeneration. Data of genebanks contributing to the survey (see chapter 6.3) are shown for all collections (total) and by region. North American genebanks (USA004 and CAN064) do not indicate having urgent regeneration needs. 72 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO for in vitro slow growth storage about 10 plantlets are Parally unique (16) Fully duplicated (2) used. Since specific allelic combinations are main- BEL023 IRL036 BGR001 IRL012 tained, a higher number of plants is only necessary CHL071 Fully unique (1) to assure that the material is not lost due to environ- CHN122 COL017 mental risks. However, a backup in vitro or cryopreser- CUB005 DEU159 Mostly unique (11) vation is strongly recommended. EST019 ARG1347 IND665 BRA020 NLD037 Improved varieties and breeding lines . Comparable to CAN064 PER001 CZE027 landraces, the collections of improved varieties (16,147 ROM007 ECU023 accessions) and breeding lines (19,932 accessions) can RUS001 ESP016 GBR251 FRA010 be maintained in the field but are mostly stored in in GBR165 JPN183 vitro slow growth conditions. About 1,000 accessions SVN019 LVA006 (6.4%) of improved varieties and 700 accessions (3.4%) USA004 PER860 SWE054 of breeding lines are in urgent need of regeneration. Again, Latin American genebanks, specifically BRA020, Figure 8 .3 .1 . Duplication status (excluding safety backup) and CUB005, COL017, GTM001, reported serious problems uniqueness of the 32 genebanks participating at the survey. in regenerating improved varieties and BRA020 and Security backups. About 47% of the survey partici- CUB005 in regenerating breeding lines. In Europe, pants indicated organizing an active safety back up the high interest of breeders in this material ensures system at an external location or at their own facility appropriate storage conditions for most of the mate- (25%) (Table 8.3.1). As reported in chapter 7 and rial kept in vitro. However, urgent regeneration is also briefly summarized here, this system is well devel- needed for accessions of improved varieties in IRL012, oped for wild species maintained as orthodox seed GBR0165 and specifically for breeding lines in BGR001. and, except for COL017, ECU023 and GTM001, most In the last survey, no need for regeneration was seed accessions are also kept at the SGSV (Figure reported (van Soest, 2006). However, as the number of 7.1.1). Landraces, improved varieties and breeding accessions has increased significantly in the last years lines maintained as clonal plants in the field or in (+5,000 accessions of improved varieties and +7,000 vitro are backed up to a lesser extent (Figure 7.1.1). accessions of breeding lines), the regeneration capaci- However, about 100% of the in vitro collections of ties may not be sufficient to maintain all new lines. CAN064, IND665, PER001, SWE054, USA004 are safety backed up via dormant mini tubers or in vitro plant- 8 .3 Duplication status and security lets at external locations and about 100% of the field backups collections of CAN064, IRL036 and PER001 are dupli- cated at different locations. Only a few institutions The viability of plant genetic resources can be rapidly (PER001, DEU159, JPN183, CEZ027) have initiated lost when environmental conditions are not adequate the safety duplication through cryopreservation and for growth. Biotic and abiotic stresses caused by only DEU159 has backed up the cryocollection at an fluctuations in growth conditions, pests, diseases and external location. handling errors affect reproduction capacity, genetic stability and, consequently the survival and quality of Different survey participants reported challenges to the resources. To minimize the risk of losing valu- safety backup the collections. In most cases, duplica- able accessions during conservation, duplication and tion is labor intensive (ARG1347, FRA010) and requires security backups of the material is common practice additional expense (GBR165) for multiplication of seed in genebanks. The Genebanks Standards for Plant or clonal plants. The current COVID-19 situation has Genetic Resources for Food and Agriculture (FAO, increased the challenges for multiplication in some 2014) provide guidelines to back up collections (seed, institutions (PER001). In addition, extensive storage field and in vitro). capacities of collaborators are required and often unavailable (PER860). Political and logistic hurdles Duplication status . Seventeen survey participants (COL017), breeders’ rights (JPN183) and phytosanitary indicated that the germplasm is partially (ARG1347, certificates (GBR165) complicate the situation and BRA020, CZE027, COL017, ESP016, FRA010, JPN183, 56% of respondents mentioned constraints to dupli- LVA006, PER860) or fully genetically unique (COL017) cating their material elsewhere (Table 8.3.1). and is not maintained in another potato collection (Figure 8.3.1). Although genebanks are very efficient 8 .4 Distribution when the material is unique and not duplicated else- where, the risk of losing unique genotypes is high and National and international distribution . The value the availability for distribution is hampered. There- of germplasm can only be recognized and exploited fore, it has been common to duplicate and exchange by distributing the material to breeders, researchers, the material among genebanks. farmers and other potential users. Access to the ger- GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 73 mplasm is subject to both national and international Predictions about future distribution . The delivery regulations (see chapter 11) and approximately half and request of genetic resources depends on political of the conserved material (46.0%, 30,900 accessions) decisions, environmental changes and socio-economic is available at the national level and one third (36.7%, factors. However, most genebank curators find it diffi- 24,600 accessions) at the international level (Figure cult to estimate whether this situation will change (28, 8.4.1). or 47%) or predict “no change” (31) in the current sit- uation (Table 8.4.1). However, curators of Latin Amer- Overall, for regional, national and international ican countries, especially BRA020, COL017, CHL071, distribution, most accessions are available in Europe, GTM001, PER001 and PER860, expect an increase in in North America and at CIP (PER001, International) demand for their germplasm in future. (Figure 8.4.1). In Europe, the survey participants estimated that about 14,000 accessions (20.8%) are Type of material distributed . Most potato collection available nationally and 11,000 accessions (16.7%) are holders are able to provide and distribute accessions available internationally. Most of them are interna- of wild species (63%) and landraces (57%) (Figure tionally available from DEU159 (6,200 accessions), 8.4.2). The number of available accessions of improved CZE027 (2,640 accessions) and NLD037 (1,450 acces- varieties and breeding lines is strongly limited and sions). RUS001 (1,200 accessions), IRL012 (600 acces- only 36% and 18% are available, respectively. Euro- sions) and IRL036 (700 accessions) provide material pean countries, PER001 and Latin and North Amer- only at the national level. Latin American countries ican countries can provide the most wild species and can provide up to 4,100 accessions (6.1%) at the landraces. Improved varieties and breeding lines are national level, most by ARG1347 (1,500 accessions), additionally available in Asian countries, in particular COL017 (1,600 accessions) and CUB005 (600 acces- CHN116 and JPN183. sions). At the international level, material is only avail- able from ARG1347 (1,500 accessions) and BRA020 Due to political regulations, there are some discrep- (200 accessions). PER001, USA004 but also CAN064 can ancies between the type of material and availability provide about 65% (4,900 accessions), 98% (5,800) and at national and international level. Most wild species 100% (100), respectively, at national and international can be supplied mainly as seeds by USA004 (4,000 level. Although up to 46% of the material is available accessions), DEU159 (1,200 accessions), NLD037 (1,200 at the national level, only a small part (16%) has been accessions), PER001 (1,200 accessions) and ARG1347 requested (Figure 8.4.1). At the international level, the (1,100 accessions). Landraces are usually available in situation is worse. Here, only 2% of the material has the form of tubers or in vitro plantlets and can be been requested indicating some challenges in using delivered by PER001 (3,400 accessions), DEU159 (2,200 the germplasm. accessions), USA004 (1,200 accessions), ARG1347 Table 8 .3 .1 . Duplication status and constraints of survey participants to duplicate potato germplasm elsewhere.   Yes No No answer Total Safety duplication in other institutions? 47% (15) 50% (16) 3% (1) (32) Any safety duplicates in the own facilities? 25% (8) 63% (20) 13% (4) (32) Constraints to duplicate elsewhere? 34% (11) 56% (18) 9% (3) (32) Asia Europe Interna onal La n America North America Na onally distributed Na onally available Regionally distributed Regionally available Interna onally distributed Internaonally available 0 25 50 75 100 Available and distributed material [%] Figure 8 .4 .1 . Availability and distribution of potato germplasm of genebanks participating in the survey. Black bars represent the total amount of distributed material. 74 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO (400 accessions) and COL017 (1,200 accessions). Most dures for packaging and shipping are less developed improved varieties are available from DEU159 (1,900 and only 15 genebanks have adequate procedures for accessions), CHN116 (700 accessions), CZE027 (700 this. accessions) and IRL015 (500 accessions). Breeding lines can be requested from CHN116 (1,400 accessions), Recipients of distributed material . Based on the JPN183 (700 accessions) and DEU159 (600 accessions). average of three years, 21 genebanks distributed approximately about 12,000 potato accessions (Figure Adequacy of distribution procedures . One third of the 8.4.4). Eleven genebanks delivered more than 100 genebanks (13) have the capacity to provide land- accessions, including USA004 (7,000 accessions), races, improved varieties and breeding lines as clonal PER001 (1,900), DEU159 (830), FRA010 (500), SWE054 in vitro plantlets (Figure 8.4.3). Most participants (380) and NLD037 (300). On average, about 66.4% of are able to provide between 1–6 in vitro plants or the material was requested by domestic users, 9.6% minitubers for a standard request. Depending on the by academic researchers, 7.2% by foreign users, 5.6% type of user and the request, the curators of DEU159, by farmers and farmers’ organization, 3.0% by private EST019, FRA010, GBR165 and LVA006 can also provide plant breeders and 1.1% by NGOs. However, the users between 2–6 tubers. In terms of seed, sufficient or of the delivered material differ between the coun- partly sufficient amounts are available for distribution tries and may reflect the different strategies of the by nine and five potato collections, respectively, and genebanks. In AGR1347, CHN122, COL017, DEU159 often about 50 seeds are provided. Most genebanks and GBR251 most users were academic researchers. have sufficient (23 participants) or partly sufficient In CZE027, SWE054, PER001, USA004 and CAN064, (two participants) procedures for preparing phytosani- domestic users requested most material. In FRA010 tary certificates and 24 participants have at least partly (500 accessions), private plant breeders are most sufficient procedures for healthy distribution. Proce- interested in the accessions. Material was supplied to Table 8 .4 .1 . Expected changes in the distribution quantity of genebanks participating in the survey. Increasing Decreasing No change Don’t know No answer Total Nationally 25% (8) 3% (1) 31% (10) 28% (9) 13% (4) (32) Regionally 16% (5) 3% (1) 22% (7) 38% (12) 22% (7) (32) Internationally 13% (4) 3% (1) 25% (8) 47% (15) 13% (4) (32) Asia Europe Interna onal La n America North America Wild species Landraces Improved variees Breeding lines 0 25 50 75 100 Available material [%] Figure 8 .4 .2 . Type of available germplasm at different potato germplasm collections participating in the survey. Sufficient partly sufficient not sufficient Don‘t know Sufficient in vitro plants Sufficient seed amount Sufficient health Phytosanitary cer ficate Packaging adequate Shipping adequate 0 5 10 15 20 25 30 Number of genebanks Figure 8 .4 .3 . Availability of the germplasm and adequate procedures for distribution of genebanks participating in the survey. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 75 NGOs from DEU159, SWE054 and CAN064. There are the type of users (i.e. users from developed or devel- also some genebanks that reported not having distrib- oping countries, hobby growers) or charge a general uted any material in the last three years (i.e. BGR001, fee per accession (JPN183: Yen 570; PER001: USD 20; GTM001, LVA006), or that do not keep records of dis- IND665: Rs 5000; DEU159: EUR 2). The shipment proce- tributions (i.e. PER860 and LVA006). When genebanks dure is in most cases covered by the recipients and can provided large amounts of material, it can be accessed range from the cost of postage to USD 500 (BRA020). through different websites, including GRIN-Global, Similarly, the costs for the phytosanitary inspections Genesys, EURISCO and Europotato, or the institu- and certificates must also be paid by the recipi- tion-specific websites of DEU159, GBR251 and NLD037. ents and can range from USD 75 (PER001), EUR 200 (LVA006) and shared costs for ELISA tests (FRA010). Most genebanks (20) have restrictions on the usage of the material and charge (12) for distribution (Figure 8 .5 Challenges and predictions for col- 8.4.5). The restrictions are often based on legal aspects lection management or agreements (e.g. ITPGRFA) and the material is usually only delivered after fulfilling country spe- Limitations . Potato collections can be composed of cific access laws and transfer agreements (BRA020, wild species maintained and distributed as seeds, as CAN064, COL017, ECU023, EST019, GBR251, GBR165, well as landraces, improved varieties, breeding lines PER001). Other collections are reserved for researchers and research collections usually maintained and dis- only (BGR001, PER860) or researchers and breeders tributed as clonal plants in the form of tubers, in vitro (CZE027, FRA010) or to researchers, breeders and for plants or minitubers. The basic maintenance (Figure educational programs (NLD037, SWE054, PER001) 6.1.1) of the different types of germplasm requires and depend on the availability of material (IRL012). various basic equipment and facilities, including fields, When the material is released for distribution, most greenhouses, growth cabinets with different tempera- genebanks can cover the cost of the propagation and tures, cold storage, tissue culture facilities, and facili- storage of the accession (19 genebanks) but only 14 ties for cryopreservation. Additional staff, equipment, and 12 genebanks are able to cover the costs for the consumables and IT support are required when the shipment and phytosanitary inspections and certifi- collection is regenerated, duplicated, digitized, distrib- cates, respectively. When costs are incurred, some gen- uted, characterized and evaluated. ebanks (DEU159, PER001) often differentiate between Accessions distributed Accessions informa�ons available Asia CHN122 100 h ps://ivf.caas.cn/ Europe CZE027 100 hps://www.vubhb.cz/en0, h ps://grinczech.vurv.cz/gringlobal/search.aspx DEU159 830 h ps://gbis.ipk-gatersleben.de/gbis2i, h ps://eurisco.ipk-gatersleben.de/ FRA010 500 h ps://www6.rennes.inrae.fr/igepp_eng/About-IGEPP/Pla�orms/BrACySol GBR251 180 h ps://ics.hu on.ac.uk/germinate-cpc SWE054 380 h ps://www.nordgen.org/en/our-work/nordgen-plants/seed-and-potato-requests Interna�onal PER001 1,900 h ps://genebank.cipotato.org/gringlobal La�n America ARG1347 150 h ps://inta.gob.ar/documentos/banco-ac�vo-de-germoplasma-de-la-eea-balcarce COL017 100 h ps://www.grin-global.org/ North America USA004 7,000 h ps://npgsweb.ars-grin.gov/gringlobal/search CAN064 180 h ps://pgrc-rpc.agr.gc.ca/gringlobal/search Total 5.1 9.6 66.4 7.2 11,980 Farmers Domes�c users Private plant breeders 0 20 40 60 80 100 Other genebanks Foreign users NGOs Researchers Plant breeders Others Distributed material [%] Figure 8 .4 .4 . Recipients of the distributed material. Right, number of accessions distributed as an estimated average of three years. Cost of Cost of Cost of Restric ons accessions shipment pyhtosanitary 3 6 7 7 9 14 12 7 19 20 11 13 Free, no restric ons Cost, restric ons No response Figure 8 .4 .5 . Restrictions and costs of distributions of genebanks participating in the survey. 76 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Most curators consider staff shortages to be a major agation behavior. Low viability of the accessions, seed problem (Figure 8.5.1). In total, 15 potato collections set and available quantities of seed are of concern for have had to reduce staff in recent years. The technical five curators. Two curators need improved protocols support in BRA020, for example, has been halved, as for pollination, seed germination and seed storage between 2016–2021 the technicians in the in vitro and two curators need improved procedures to elimi- laboratory were reduced from four to two and in nate duplicates. Other constraints may be difficult to the greenhouse and field from five to two (personal change: limited access to germplasm collection due communications with Caroline Castro, 2021). Simi- to legal regulations (5) and environmental stresses larly, the limitation of funding reported by 14 cura- during reproduction in the field (5). tors increases the risk that equipment and facilities cannot be renewed and updated. As a consequence, The survey participants were asked to predict the most curators report a lack of, broken or old facili- future situation for their collection management. ties and equipment (12), problems with plant health, Between 21–29 participants could forecast the situa- virus testing and elimination (12) as well as limited tion in 2025 (Figure 8.5.2). capacities for hiring trained staff (10), for charac- terization and evaluation (8), digitalization of data Predictions on funding . Funding is moderate in Asia (4), genotyping (4) and cryopreservation (3). As staff with little change expected, although JPN183 expects and funding are essential for the propagation of the some cut by 2025. In Europe, the situation of eight material, a shortage forces the curators to focus on collections is good (DEU159, IRL036, ESP016, EST019) the most basic processes or to reduce the number of or moderate (four genebanks). Only two genebanks accessions within the collection to a manageable level (NLD037, BGR001) suffer from a lack of funding and and decrease the risk of losing valuable material. most expect this situation to change. Most collection curators in Latin America (ARG1347, BRA020, CUB005, Other constraints relate to a lack of research on PER860) confront serious funding problems, but some potato genetic resources and their storage and prop- expect the situation to improve (ARG1347, COL017, Field Avail- ability for repro- duction (2) Further data Digitalisation Restricted access More cryo- (4) to germplasm preservation due to legal (3)Elimination of rules duplicates (2) Elimination (5) Increased environmental stress of duplicates (2) during reproduction (5) Staff shortage (15) Low Accessions Viability, Lack of/ broken/ old Seed set, Amount (5) Facilities and equipment (12) Figure 8 .5 .1 . Constraints faced by the 32 genebank curators in the last years. The numbers in brackets indicate the number of genebank curators that have been confronted with these specific problems. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 77 Limted Funding (14) Plant health Virus testing & elimination (12) Availability of protocols (Pollination, Seed germination, More Seed storage) (2) collection More genotyping (4) missions (1) More characterisation/ Evaluation/taxonomic Studies (8) Availability of trained staff, Training possibilities (10) PER860). The curators of PER001 expect a further cut SVN019, SWE064) expect a substantial change. Only in basic funding. CHL071, FRA010, IRL012, GBR165, CUB005 predict that the situation will remain unsatisfactory or expect it to Predictions on staff retention . The situation regarding worsen. the retention of staff is comparable to funding. Here, CHN122 and Latin American collections (CUB001, Predictions about user support . Most curators do not PER860) expect the situation to improve. Depending expect strong support or feedback by users. Only few on the country, the situation in Europe is very dif- curators (GBR251, USA004, BRA020) report good feed- ferent. A good to moderate situation is reported by back and expect this situation to continue. PER860 and BEL023, CZE027, DEU159, ESP016, EST019, FRA010, BGR001 predict strong change and improvement. GBR165, IRL036, LVA006, NLD037, ROM007, SVN019 and SWE054, whereas GBR251 faces some problems. Predictions about donor interest . Of the 21 genebanks FRA010, GBR165, GBR251, LVA006, expect more chal- able to assess this situation, Latin American gene- lenges in this area by 2025. The situation for USA004 is banks (CHL071, COL017, ECU023, PER860) indicated moderate. that donor awareness of the need for conservation is poor. An improvement of the situation is only seen by Predictions on genetic variation in the collections . PER860, LVA006, ESP016. Most participants assume that genetic variation in the collections is sufficient to good and expect it Predictions about the level of use by breeders . Most to remain sufficient in future. Overall, the curators genebanks expect a positive change in the use of the of BEL023, COL017, IRL012 and JPN183 assume that collections by breeders. Currently, some Latin Amer- genetic variability in the collection is not adequate ican (CHL071) and European (FRA010, IRL012, LVA006, but do not expect this to change in the future. USA004) collections are frequently used by breeders, while other European (BEL023, BGR001, CZE027) Predictions on access to information about the and Latin American genebanks (ARG1347, COL017, germplasm . Based on improved digitalization, net- BRA020, PER860) anticipate an increased use of the work activities and various global initiatives, most collections for breeding in the future. participants predict a significantly improved access to information. Although access is currently not at the Prediction on the level of use by researchers . Most level desired for some collections, Asian (CHN122), Latin American (ARG1347, BRA020, COL017, CUB005), Latin American (ARG1347, BRA020, CHL071, PER860) European (BEL023, BGR001; CZE027, DEU159, FRA010, and European genebanks (BEL023, FRA010, IRL012, EST019, ESP016, GBR251, GIRL012, NLD 037, IRL036, Reten on Needed gene c Access to Funding of staff variability informa on Total (32) 27/24 27/26 25/24 29/28 Asia (4) 3/3 3/3 3/3 3/3 Europe (17) 14/12 15/14 13/12 16/15 Interna onal (1) 1/1 1/1 1/1 1/1 Lan America (8) 8/7 7/7 7/7 7/7 North America (2) 1/1 1/1 1/1 1/1 3 2 1 3 2 1 3 2 1 3 2 1 Support by Interest of Use by Use by users donors breeders researchers Total (32) 23/21 21/20 26/24 26/24 Asia (4) 3/3 1/1 3/3 3/3 Europe (17) 12/10 10/9 14/12 14/12 Interna onal (1) 1/1 1/1 1/1 1/1 La n America (8) 6/6 6/6 7/7 7/7 North America (2) 1/1 1/1 1/1 1/1 3 2 1 3 2 1 3 2 1 3 2 1 Expected situa on by 2025 Figure 8 .5 .2 . Current and expected situations in the collection management of 32 participating genebanks by 2025. The numbers at the end of each line indicate the current/ expected situation indicated by the respondents. 1 = high/good, 2 = adequate/moderate, 3 = not sufficient/bad. 78 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO LVA006, SWE064, USA004) and Asian (CHN122, (COL017, ECU023, GTM001, PER860) are challenged by IND665) genebanks consider that they are already continuing plant propagation in the field and require moderately or well used by researchers and most urgent regeneration. Serious problems are also expect this situation to improve. CHL071, ECU023, reported for improved varieties and breeding lines SVN019, JPN183, however, predicted no change in this in BRA020, CUB005, COL017 and GTM001. In Europe, area. Asia and North America, only a small portion of the collections are in urgent need of regeneration, and Overall, except for funding, staff retention and thus the situation is less critical compared to gene- user support, most aspects are projected to slightly banks in Latin American. improve. Most improvements were seen in the area of accessibility of accession information and use by Plant health . Plant health and the possibilities of virus breeders, which may in turn improve the funding situ- testing and elimination are major constraints for man- ation in the future. aging and distribution of the collections. Therefore, funding has to be improved for plant health testing 8 .6 Recommendations to improve and virus elimination to make collections available for collection management use. Protocols . Only nine genebanks (DEU159, ESP016, Safety duplication . Some of the clonal collections con- EST019, NLD037, PER001, RUS001, SVN019, SWE054, sidered as fully (COL017) or mostly unique germplasm USA004) keep protocols for all procedures and two (ARG1347, BRA020, CZE027, COL017, ESP016, FRA010, (DEU159, NLD037) are certified by ISO 9001/2015. In JPN183, LVA006, PER860) have not been duplicated summary, fundamental aspects of potato maintenance elsewhere. Therefore, there is an urgent need to are documented by most genebanks. However, most support duplication activities and to overcome hurdles genebanks participating in the survey cannot provide such as national regulations, intellectual property pro- protocols for all procedures. To ensure high quality tection and phytosanitary issues to ensure the safety of the seed and clonal material and an appropriate duplicated storage of plant genetic resources. guidance for technical staff, it is highly recommended that all procedures are fully documented. Distribution . Although about 30,900 accessions are available for distribution, only 12,000 distributed Regeneration . Regeneration capacity needs to be accessions were finally delivered, most by the largest improved, especially in Latin American countries. collections (DEU159, USA004, PER001) or other Euro- About 8.3% of wild species accessions maintained pean genebanks. However, to stimulate the use of the require urgent regeneration. In particular, the need germplasm, the accessibility of the material based on to regenerate a total of 1,210 accessions is high in legal regulations and accession information (digitized ARG1347, CUB005, ECU023, GTM001 and PER001. To passport, characterization and evaluation, and geno- avoid the risk of genetic drift and reduced seed set, typing data) has to be improved, in addition to better plant propagation with a higher number of individ- health conditions including virus elimination and uals in the population is required for seed production phytosanitary certification. from wild species. About 12.1% of landraces, 6.4% of improved varieties and 3.4% of breeding lines are Staff training programs. About 10 curators were con- maintained as clonal plants in in vitro or in the field cerned about the retention and the training possibil- and require regeneration. In particular, landrace acces- ities of genebank staff. International online training sions (1,600 accessions) in Latin America genebanks programs could help to support adequate training. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 79 9 DATA MANAGEMENT 9 .1 Management and types of gene- bank data Passport data Plant health Collec on Characteriza on data inventory Genebanks generate a large amount of informa- data tion during acquisition, registration, storage, mon- Protocols, SOPs Evaluaon itoring, regeneration, characterization, evaluation Publica ons data and distribution. This data (Figure 9.1.1) can be fairly static with a high degree of use and low frequency of updating, such as passport data, characterization Historic data data and protocols or standard operating procedures. Other information, such as phytosanitary certificates, Note down Fieldbook inventory and evaluation data need to be updated on paper! more frequently. For short term and internal collection Frequency of update management, field books and specific lists are used. All these data have different formats and relevance. Figure 9 .1 .1 . Degree of use and required update frequency of genebank data (personal communication with Matija Obreza, To ensure transfer of knowledge, and thus the effi- 2022). cient conservation and utilization of germplasm, these data must be stored and maintained adequately. most genebanks compiled a catalogue, the so-called ‘Index Seminum’. Due to the complexity of the gene- Genebank data was for a long time managed using bank processes, the first data management software paper index card systems and registers, and documen- was introduced to genebanks in the late 1960s and in tation focused mainly on the origin of the material DEU159 in the early 1980s (Knüpffer, 1989; Menting and taxonomic classification (Weise et al., 2020). To et al., 2007). The largest genebanks were able to make the material more accessible for outside use, implement their own in-house systems, such as GBIS 80 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Digital entry of herbarium information at CIP. Photo: Michael Major/Crop Trust Frequency of use M. Nagel (2022) at DEU159 (Oppermann et al., 2015), GENIS at NLD037 banks, here specifically potato collections, evaluating (Menting et al., 2007) or Alelo at BRA020 (Alves and and adopting GRIN-Global is increasing (Figure 9.1.2). Azevedo, 2018). Some countries also developed trans- boundary cooperation networks such as the SESTO To ensure long-term knowledge transfer and effi- management system of the Nordic and Baltic countries cient management, high priority should be given by or the Intergenebank Potato Database (Huamán et genebanks to the development and implementa- al., 2000). SESTO was replaced by GRIN-Global in 2020. tion of an effective information system. Figure 9.1.3 The Germplasm Resource Information Network (GRIN) clearly shows that paper and spreadsheet tools are an was initially developed by the United States Depart- intermediate solution and have their own advantages. ment of Agriculture (USDA). Thanks to joint efforts For long-term reliability, consistency and accessibility, of the Global Crop Diversity Trust, Bioversity Interna- however, only databases and trained staff can ensure tional and the USDA’s Agricultural Research Service, sustainable genebank management. Unfortunately, GRIN-Global has been an open access tool since 2011 due to lack of funding and IT support, some gene- and provides a well-developed platform to manage banks are hardly able to use databases or to generate genebank data, including inventory management. or transfer data to an appropriate system. Since 2021, the new GRIN-Global Community Edition (GG-CE) offers a user-friendly interface for using and Genebank information management systems typically capturing data on mobiles, tablets and desktops, comprise three to four layers, including basic infor- improved taxonomy search pages and enhanced access mation, so-called passport data, conservation man- for public websites. As a result, the number of gene- agement data, characterization and evaluation data, NOR061 SWE054 EST019 LTU001 PRT102 CZE027 USA004 COL017 BOL317 PER001 CHL071 URY003 CHL179 Figure 9 .1 .2 . Potato germplasm collections that have already implemented (green) GRIN-Global (Source: personal communications Juan Carlos Alarcon Maldonado, CropTrust, 2022) Safety and accessibility of genebank data Informa on systems Paper Spreadsheet tools (GRIN-Global, etc.) - - lack of control - costly (storage, print) - collabora ve work difficult - complex - no search func on - hard to consolidate - me-consuming - collabora ve work difficult - prone to human errors & data loss - costly + - high flexibility - ease of use - access control - easy to create - search func on - search func on - consistent - ease of sharing - reliable - consistent Figure 9 .1 .3 . Pros and cons of the different tools used for the management of genebank data. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 81 M. Nagel (2022) M . Nagel (2022) and in few cases genomic data (Figure 9.1.4) (Weise et through the GLIS DOI portal. The DOI system allows al., 2020). The FAO Commission on Genetic Resources genebank accessions to be linked to datasets, and for Food and Agriculture (FAO, 2014) has developed enables publications and genomic data to be found recommendations on data standardization in the automatically when DOIs are provided. Genebank Standards and has also included standards for passport data (Alercia et al., 2015). In addition, Managing of potato collections is particularly chal- other international initiatives such as the Interna- lenging due to the conservation of wild species tional DivSeek Network are elaborating standards and through true potato seed and of landraces, improved supporting the creation, integration and exchange varieties and breeding lines by clonal propagation of germplasm data. Furthermore, the Secretariat of (Figure 9.1.4). The crop therefore requires tools, the International Treaty on Plant Genetic Resources protocols and operational procedures for the docu- for Food and Agriculture (ITPGRFA) has supported mentation of herbaria, field genebanks, seed storage, the introduction of Digital Object Identifiers (DOI) in vitro banks, dry (lyophilized) leaf banks, cryopreser- as unique and stable identifiers for genebank acces- vation, plant health status, safety backup and distri- sions (Alercia et al., 2018) which are easily accessible bution. Smaller genebanks in particular struggle to Passport Informaon - Accession number - Year of acquisi on - History, Pedigree - Taxonomic name - Donor - Legal status - Digital Object Iden fier (DOI) - Collec ng mission - Pictures - Biostatus - Loca on of collec on (ecogeographic data) Conserva on Management - Loca on - Propaga on methods - collec ng permits - Inventory - Viability test methods - SMTA - Storage methods - Plant health tes ng/cer ficates Characterisa on and Evalua on Data - Genebanks‘ C&E Data - Breeders‘ C&E Data ??? - Potato Descriptors (Human et al. 1977) - Descriptors and other traits Genomic Data Genebank Informa on Systems - o�en project data ??? - GRIN-Global - standards under development - GBIS, Alelo, Paradox, GENIS - published o�en seperately GRIN EURISCO Crop TMIP ??? NCBI Germinate INSDC GENESYS WIEWS JACQ DDBJ Figure 9 .1 .4 . Consolidation and transfer of data through genebank information systems and web portals. EURISCO, European Search Catalogue for Plant Genetic Resources; Crop TMIP, Crop Trait Mining Informatics Platform; C&E, characterization and evaluation data; DDBJ, DNA Data Bank of Japan; INSDC, International Nucleotide Sequence Database Collaboration; GBIS, Genebank Information System; Genesys; Global Portal on Plant Genetic Resources; GENIS, Germplasm Resource Information Network; GRIN, Germplasm Resource Information Network; JACQ, jointly administered herbarium management system; NCBI, National Center for Biotechnology Information; SMTA, standard material transfer agreement; WIEWS, World Information and Early Warning System on Plant Genetic Resources for Food and Agriculture. 82 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Access Systems Genebank Management Data Herbarium Field Bank Seed storage In vitro Bank DNA Dry leaves Cryopreservaon Plant health M.Nagel 2022 Safety backup Distribuon ASSP ORT ATION AL P INTER N NAME Leona Negra , CIP 7 04058 h ps:/ /doi.o rg/10. 18730 /A7HA DOI SPECIE S COUN TRY of ORIGI N Solanu m tub erosum Ecuad or CIP 70 4058 <<<< < < <<< < <<<< <<< <<< <<<< <<<< <<<< LEONA NEGR A h ps:/ /doi.o rg/10. 18730 /A7HA implement the various tools needed to manage their port data (61%) is the most frequently digitalized collections. In addition, genebanks generate charac- followed by the characterization (33%) and evalu- terization and evaluation data based on descriptors ation data (32%) (Figure 9.2.2). About 15 curators for “Utilization of the genetic resources of the potato indicated that they organize some of their data in II” (Huaman et al., 1977; Gomez, 2000). This data can paper. About 100% of the passport data is available also be transmitted to aggregator systems such as electronically for ARG1347, BRA020, BGR001, CHL071, EURISCO and Genesys. Although many collections are CZE027, CUB005, DEU159, ECU023, ESP016, EST019, currently phenotyped and genotyped by breeders and JPN183, LVA006, NLD037, PER001, ROM007, GBR251, third-party projects, the link between these and the SVN019 and SWE054 and USA004. For characterization genebank is poor. The DOI could support the trace- and evaluation data, only ECU023, EST019, JPN183, ability of these accessions. However, standards need to SVN019 and USA004 reported to have 100% of their be developed and the links improved for the extended data available electronically. Although digitalization usability of all these data. of data seems to have improved in recent years, it is strongly recommended that 100% of passport data 9 .2 Accessibility of potato germplasm and much more characterization and evaluation data data be made electronically available. Most genebanks holding potato germplasm use elec- In total, 19 genebanks provide direct access to a data tronic information systems to manage data on their subset through their own or other websites (Table collection. However, only 13 of these genebanks have 9.2.1), with one third of the collections nationally fully implemented genebank information systems, (BGR001, CAN064, ECU023, ESP016, DEU159, IRL036, of which seven (CAN064, COL017, CZE027, EST019, RUS001, SVN019, SWE054) and internationally PER001, SWE054, USA004) use GRIN-Global (Figure (CZE027, BGR001, DEU159, EST019, GBR251, IRL012, 9.2.1). Other genebanks have developed in-house IRL036, LVA006, NLD037, PER001, RUS001, SWE054, systems such as GBIS (DEU159), Paradox (RUS001), USA004) available (Figure 9.2.3). The curators of 10 Germinate (GBR251), GENIS (NLD037), Alelo (BRA020), collections reported that the material is not accessible SIRGE (PER860) and three genebanks use other solu- via internet (Figure 9.2.4). However, the European tions (GBR165, ESP016) such as MS Access (IRL036). genebanks often use EURISCO and the European Although two collection holders (BEL023, CHN122) cultivated potato database as web portals, PER001 and indicated that they do not use electronic systems and USA004 uploading data to Genesys. two genebanks did not respond, spreadsheets (i.e. MS Excel) are commonly used for data storage. As men- tioned above, spreadsheet tools are advantageous Passport Characterisa on Evaluaon intermediate solutions and can be structured in a way data data data that facilitates the uploading of data into genebank information systems. To ensure long-term safety, reliability, consistency and accessibility of data, the 33% 32% implementation of genebank information systems is 61% strongly recommended. Similar to the previous survey (van Soest, 2006), and as 12% an average across the 32 survey participants, pass- 25% 20% Yes (15) Spread- Figure 9 .2 .2 . Digitalization and availability of passport, Others sheet characterization and evaluation data in potato germplasm (11) collections. Responses of 32 survey participants. *(2) (10) GRIN Yes partly No No(3) Partly (12) (7) Interna onal Regional Na onal Figure 9 .2 .1 . Potato collections using electronic information systems fully or partially. Among them, seven genebanks 0 5 10 15 20 25 30 use the genebank information system Germplasm Resource Number of genebanks Information Network (GRIN). The number in brackets indicates Figure 9 .2 .3 . Number of potato germplasm collections that the number of responses. *no response; others indicate the provide data in national, regional and international databases. usage of information systems such GBIS, Paradox, Germinate, Green, data are included; yellow, data partly included; red, GENIS Alelo or Sirge or other laboratory information systems data are not included in external databases; grey, no response. (LIMS) or a combination of different systems. Responses of 32 survey participants. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 83 Paper Digitalised The EURISCO catalogue stores passport and pheno- (VIR, RUS001) and INTA, Balcarce (ARG1347) (Huamán typic information on plant genetic resources from et al., 2000). The IPD shows a global inventory of about 400 European institutes and 2 million acces- wild potato germplasm and matches accessions, thus sions. It is hosted and maintained at the Leibniz duplicates that have been collected during the same Institute of Plant Genetics and Crop Plant Research mission but stored in different genebanks using dif- (DEU159) on behalf of the European Cooperative ferent identifiers. Data from USA004 and NLD037 has Program for Plant Genetic Resources (ECPGR). Data been recently updated and the database, basically an collected are based on the National Inventories of 43 Excel sheet, is still maintained by CIP and is accessible member countries (Weise et al., 2017). Currently, data online. Over decades, IPD has supported collecting on about 15,000 accessions of S. tuberosum (19,000 missions, research, collection management and can be accessions including synonyms) is accessible; including the basis for the identification of core collections (per- 4,200 accessions from DEU159, 2,400 accessions from sonal communications John Bamberg, 2022). However, CZE027 and 800 accessions from EST019. it would be helpful if this database is combined with data accessible through EURISCO or Genesys. Genesys is hosted by the Crop Trust and provides global access to information on plant genetic resources. It Genesys and EURISCO substantially support the conser- includes about four million accessions from 450 insti- vation management, and hence the maintenance of tutions around the globe including data from EURISCO the diversity of plant genetic resources, including dupli- and CGIAR genebanks. Genesys supports passport and cate finding, gap analysis and providing a link between phenotype data and can identify potential replicates/ passport, phenotypic and genomic data. However, duplicates in the database based on available passport it is a prerequisite that IT infrastructure and trained information. Genesys contains information on about and qualified staff are available to create, curate and 28,000 active potato accessions, including 25,000 acces- upload appropriate passport and phenotype data. In sions of S. tuberosum, 1,400 accessions of S. acaule and particular, for the effective use and reuse of pheno- 1,200 accessions of S. stoloniferum. PER001, DEU159, typic data, the FAIR (Findable-Accessible-Interopera- USA004, UKR026, CZE027 and NLD037 hold the largest ble-Reusable) guidelines are an essential element for collections according to Genesys, as also identified by WIEWS (2021). Table 9 .2 .1 . Accessibility of potato collections through fol- Beside the national and international databases, since lowing links. 1990 the so-called Inter-genebank Potato Database Institution Collection accessible (IPD) has comprised accessions of wild species from the Association of Potato Inter-genebank Collabo- Asia JPN183 Link rators involving CIP (PER001), US Potato Genebank BGR001 Link (USA004), Groß Lüsewitz Potato Collection/IPK (GLKS, Europe CZE027 Link DEU159), Commmonwealth Potato Collection (CPC, GBR251), Center for Genetic Resources Netherland DEU159 Link (CGN, NLD037), N. I. Vavilov Institute of Plant Industry ESP016 Link EST019 Link Data provided through the internet? FRA010 Link GBR251 Link 2 GBR165 Link IRL012 Link Yes (8) NLD037 Link No (10) SWE054 Link International PER001 Link Latin America ARG1347 Link BRA020 Link Partly (12) COL017 Link CHL071 Link North America CAN064 Link Figure 9 .2 .4 . Number of potato germplasm collections that provide data through the internet. Responses of 32 survey USA004 Link participants. 84 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO future data use (Ghaffar et al., 2020). Genomic data are Implementation of FAIR data policy . To enable a wide not held by these systems but are accessible via other use of plant genetic resources data, the publication of platforms such as Germinate, Solgenomics, the Spud phenotypic data should follow FAIR data principles and DB or through common platforms such as the National involve specialized platforms. Standards for the evalua- Center for Biotechnology Information (NCBI). However, tion of phenotypic data (descriptors) need to be imple- the storage of genomic data and linkage to the pass- mented in the system and used consistently to ensure a port data are not satisfactorily solved and the potato comparability of data in the future. community urgently calls for better solutions. The DOIs assigned to samples and linked to source material in Digital Object Identifiers (DOI). Consistent use of DOIs genebanks could be one of the options. for all genebank accessions, which are freely available to PGR collections through the GLIS DOI portal, should 9 .3 Required improvements for data be a requirement. The DOIs allow linking of material management across genebanks, between passport, phenotypic and genomic data, and enable direct linkage to herbarium Implementation of genebank information systems . sheets that are often accessible via other platforms The quality of genebank management is substantially such as JACQ, a jointly administered herbarium man- linked to the quality of data management, as knowl- agement system. edge and information can be best transferred via stan- dardized and high-quality data and workflows. Top Staff training programs . In order to implement stan- priority should, therefore, be given to the implementa- dards and to create and digitalize phenotypic data, tion of a genebank information systems at every orga- staff must be qualified. Therefore, specific training nization conserving potato germplasm, with the elec- programs for data management must be implemented. tronic recording of all data, including the electronic availability of passport, characterization and evalua- Genomic data . The current link between accessions and tion data and digitalization of voucher specimens. In genomic data is unsatisfactory. Therefore, standards addition, links need to be elaborated between acces- need to be further developed and the access clearly sion IDs in different genebanks available in IPD and described and linked. should be integrated in genebank data management systems and data transferred to the public domain. Identification of duplicates . To rationalize genebank Public availability of data is a prerequisite for identifi- collections, duplicates and unique accessions must be cation of unique accessions and duplicates, the analysis clearly identified via all available data (passport, char- of gaps and the use of potato genetic resources. acterization and evaluation, genomic data). Guidelines for the identification of duplicates and recommenda- tion about the handling of duplicates must be devel- oped. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 85 10 COLLECTION GAPS Climate change and the growing world population 10 .1 Gap analysis – a tool to aid conser- are having a devastating impact on plant genetic vation of plant genetic resources resources, in particular on crop wild relatives and their habitats. In the US, about 7.1% of taxa of crop wild In general, specific targets for the conservation of relatives are considered as critically endangered and plants genetic resources include, for example, that 58.8% require urgent conservation (Khoury et al., 95% of all alleles of a random locus present in a target 2020). In addition, in South America, about 90% of population at a frequency of over 5% are conserved. the original Atlantic rainforest is estimated to have Marshall and Brown (1975) estimated that this could been converted to farmland and urban territories, be achieved by collecting 50 individual plants from 50 resulting in a threat to one third of the world’s plant populations/sites, although another estimate was by species (León-Lobos et al., 2012). Some potato crop collecting 172 individual plants at random (Lawrence wild relatives distributed between the southern USA et al., 1995). However, the critical minimum sizes to Chile and Argentina, an area where a quarter of all of populations to be collected is highly debatable world’s plant species are found, are critically endan- because population size in natural habitats, demo- gered in their habitats (Castañeda-Álvarez et al., graphic parameters and levels of genetic diversity 2016). Therefore, due to the great potential of crop vary and 50 or 172 accessions may not be sufficient wild relatives to contribute traits for crop improve- (Maxted et al., 2008). Moreover, Vincent et al. (2013) ment (Vincent et al., 2013) and thus for food security, showed that out of 1,667 crop wild relatives, about there is an urgent need to identify underrepresented 1,250 taxa are present in genebanks with fewer than taxa and to fill these gaps in ex situ collections before 50 accessions and 939 have fewer than 10 accessions. it is too late. Although genetic diversity in the collections has not 86 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Potato diversity . Photo: Michael Major/Crop Trust been systematically assessed by genome sequencing, and coverage, intraspecific coverage, and potential it could be speculated that there are considerable for use in a threat assessment. The third step (3) is under-representations of taxa and of genetic diversity to revise current conservation strategies based on in ex situ genebanks. To identify so-called ‘gaps’ in the the results. This could include both ex situ and in situ collections, comparisons between the actual distri- interventions. In the fourth step (4), the effectiveness bution pattern of the species and the representation of conservation needs to be assessed and priorities of these species in the collections, a so-called ‘gap continuously reviewed for both in situ and ex situ analysis’ are performed (Margules, 1989; Maxted et conservation (Maxted et al., 2008). al., 2008). This concept has recently been applied to a number of collections to improve our understanding 10 .2 Origin of the potato collections of the representation of genetic diversity stored in our assessed by the survey genebanks. In order to determine the uniqueness of the collection In principle, four steps were summarized by Burley in each country and to search for potential gaps, the (1988) and involve parameters at different levels participants were asked to estimate the proportion (Figure 10.1.1). The first step (1) involves the iden- of accessions of national, regional and global origin. tification of the specific biodiversity to be studied, On average, 32% of all accessions are considered to e.g. site, taxa or landrace group. The second step be of national origin (17,300 accessions), 13% are (2) involves describing the biodiversity including the of regional origin (6,080) and 55% are of interna- search for taxonomic details such as genus, species, tional origin (32,000) (Figure 10.2.1). Most accessions accepted classification systems and consultation with maintained in Latin America and CIP (PER001) are of taxon experts. To determine genetic diversity in gen- ebanks, the parameter ‘richness’, the total number of genotypes or alleles present, or ‘evenness’, the Na onal Regional Global frequency of different alleles, is usually calculated. Asia 4000 1800 5300 Although, genetic diversity may not necessarily be Europe related to ecogeographical differences (Del Rio and 5100 4300 10000 Bamberg, 2002), wide geographic or ecological ampli- Interna onal 4800 2700 tude is often taken as a proxy for genetic diversity La n America 5500 1900 1800 (Maxted et al., 2008). In any case, environmental niche modelling techniques and geographic information North America 600 5400 systems (GIS) are often used to determine whether 0% 20% 40% 60% 80% 100% taxa are threatened. Maxted et al. (2008) suggested Figure 10 .2 .1 . Estimated number of accessions that are of including the representation of taxa in herbarium national (black), regional (dark green) and global (brown) and ex situ collections, their geographical distribution origin. Responses of 32 survey participants. Trait level Geographical level Traits of Distribu on pa erns interest (global, regional, country or province) Can be a proxy for gene c diversity & possible bio c traits Assessment of Environmental level coverage/conserva on Taxonomic level Ecology of the species Representa on Genus, species Socioeconomic predictors in herbarium, Classifica on system Can be a proxy for possible in situ collec ons, Expert consulta on abioc traits ex situ collec ons Can be a proxy for the Usage poten al range of traits M. Nagel (2022) Gene c diversity level Thread level Species richness or evenness Taxon vulnerablility Assessment by molecular marker Ex nc on assessment Figure 10 .1 .1 . Parameters to be possibly included and considered in gap analysis of plant genetic resources. Based on description of Maxted et al. (2008). GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 87 national (about 60%) or regional origin (about 20%) coverage, with some gaps in their collection. Overall, and account for 12,200 accessions. ARG11347, CHL071, the respondents indicated that European and Asian COL017, ECU023, PER860 consider that between 88% genebanks conserve a combination of unique national and 100% of their collections are national. In North varieties and landraces or heirloom varieties, and America, most accessions were imported internation- South American landraces whereas Latin American ally and account for 90% (5,400). The collections in genebanks, CIP (PER001) and the USA004 preserve Europe and Asia come from different countries. About unique resources from Latin America. 30% (5,100) and 40% (4,000) of the accessions are from their own country, respectively. In Asia, CHN122 10 .3 Gaps considered by the survey par- and JPN183 and in Europe (IRL036, LVA006, ROM007, ticipants GBR165 and SVN019) curators estimated that 80% to 100% originate from their own country. About 25% More than 50% of the survey participants (18) are of regional origin, corresponding to 4,330 and responded that they have gaps in species coverage 1,800 accessions for Europe and Asia, respectively. (Table 10.3.1) and especially in the population rep- In Asia, about 35% (5,300 accessions) and in Europe, resentation per species (19 participants). However, about 40% (10,000 accessions) are of international the answer differed according to the location of the origin. collections. The respondents from the Asian collections (CHN116, CHN122, IND665, JPN183) suggest that gaps Most genebanks (20 out of 32) consider that they exist at the species, population and ecological repre- have good national/multinational coverage (Figure sentation levels. To fill these gaps, CHN116, CHN122 10.2.2). Asian respondents answered that the coverage and IND665 are interested in exchanging material is good for their respective countries (China, Japan). through international collaborations and introducing As well, respondents from Latin Americans genebanks specific diversity from abroad. Half of the respon- consider that they also have an adequate range of dents in the American genebanks (ARG1347, CHL028, genetic diversity from Argentina, Brazil, Bolivia, Chile, CUB005, USA004) identify no gaps in the species cov- Colombia, Ecuador, El Salvador, Guatemala, Mexico, erage, while the other half recognize gaps (BRA020, Paraguay, Peru, Uruguay, USA and Venezuela. The COL017, ECU023, GTM001, PER001) and most refer collections in Europe represent accessions from Bel- to gaps in the population representation (ARG1347, gium, Czechia, Estonia, France, Germany, Netherlands, COL017, GTM001, CUB005, PER001, PER860) and in the Nordic countries, Slovakia, Spain, UK, and certain ecological representation (ARG1347, GTM001, CUB005, regions as Suceava and Maramures. However, only PER001, PER860). Therefore, collecting missions are six genebanks (BGR001, CHN116, GTM001, RUS001, planned by ARG1347 in areas not previously visited for IND665, USA004) consider that they have good global sampling and that are represented by few accessions. Table 10 .3 .1 . Major gaps in the collections as identified by the survey participants. Are there major gaps in the collection? Yes No Don’t know Total Species coverage of the crop 56% (18) 28% (9) 16% (5) (32) Population (sample) representation per species 59% (19) 28% (9) 13% (4) (32) Ecological representation of the species 44% (14) 31% (10) 25% (8) (32) Good na onal/mul na onal coverage Good global coverage ARG1347 (Argen na), ECU023 (Ecuador) BGR001, CHN116, GTM001 BEL023 (Belgium, France) IND665 (CIP, Canada, Europe, USA) BRA020 (Brazil, Chile, Uruguay) RUS001, USA004 CAN064 (Canada), CHN122 (China) COL017 (Colombia, Peru, Ecuador, Good regional coverage Bolivia, Venezuela), CUB005 (Cuba) BEL023, IRL036 (Europe) CZE027 (Czech Republic, Slovak Republic) CUB005 (Tropical climates) DEU159 (Germany, Netherlands) CHN116, IND665 EST019 (Estonia), ESP016 (Spain) CHL071 (Los Lagos, Chile) FRA010 (France, Europe) IRL012 (Ireland, UK, Europe) GBR165 (UK), GBR251 (La n America, USA) ROM007 (Suceava & Maramures County) IND665 (India) SWE054 (Nordic regions) LVA006 (Latvia), SVN019 (Slovenia) NLD037 (Lan America) PER001 (La n America), PER860 (Peruvian departments) USA004 Figure 10 .2 .2 . Global, regional or national/multinational coverage of potato collection including predominant countries (in brackets) estimated by 32 survey participants. Multiple answers possible. 88 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO PER001 is collaborating closely with Peruvian native been reported since 2006, e.g. four missions to collect communities to introduce and conserve new unique S. chacoense and S. commersonii in Brazil between accessions. In 2017/18, a collecting mission was carried 2016 and 2018 (Medeiros et al., 2021). Although out and 330 unique accessions were added to the survey participants from Latin American countries collection. PER860 promotes the recognition of “Zonas indicated that they are highly motivated to conduct de Agrobiodiversidad” as a conservation strategy and collecting missions, several curators mentioned that strengthens in situ conservation in Peruvian indige- regional authorities are very restrictive when col- nous territories, potentially involving the exchange of lecting missions are planned and require extensive material. CUB005 and ECU023 are interested in filling documentation and lobbying. Overall, most gene- gaps and ECU023 will focus on wild species. GTM001 banks have a large and balanced representation of reports that the collection is not sufficiently character- national and international resources but gaps are still ized to identify further gaps, and COL017 is interested present (chapters 10.4 and 10.5). Survey participants in material from Colombian sites which not has been of Latin American countries indicated a strong interest covered in previous collecting missions. in identifying and filling the gaps through collecting missions and most are open to international collab- In Europe, survey participants consider that more than oration to ensure that potato diversity can be safely 50% of the originally collected material has good preserved in genebanks. Therefore, awareness of the national and regional coverage, i.e., EST019, GBR165, consequences of the loss of genetic diversity needs IRL036, SVN019 and SWE054 see no gaps and have no to be increased among policy makers and the public, plans for collecting missions. GBR165 and IRL036 reg- especially in Latin American countries. ularly add new material from the Variety Catalogues. Respondents that maintain large collections and have 10 .4 Identification of gaps in the repre- introduced most of the material from abroad recog- sentation of potato wild species nize gaps in their collections, i.e. CZE027, DEU159, FRA010, NLD037, RUS001, but have no plans to fill As a result of historic developments such as the them due to legal and phytosanitary restrictions. Irish Potato Famine, potato crop wild relatives have been used extensively for germplasm improvement. In the last survey (van Soest, 2006), the situation was Therefore, these resources had the benefit of being comparable, with 21 out of 23 participants sug- collected more frequently compared to other crop gesting that there were gaps in the collections, i.e. gene pools (Castañeda-Álvarez et al., 2016). Never- 30 wild species according to Hawkes (1990) were not theless, in order to identify gaps and priorities for represented in the collections. However, the recent further collecting mission, different types of analysis transfer of taxonomic names to the Spooner et al. have been carried out. Vincent et al. (2013) analyzed (2014) taxonomic system showed that 105 of the 107 crop wild relatives based on their social and economic accepted wild species are listed in WIEWS (2021). importance, their potential use for crop improvement When gaps are recognized, they can only be filled by and their threat status, and found that 55% of wild collecting missions or international material exchange. potato species have fewer than 50 accessions in ex situ Unfortunately, only a few collecting missions have collections. Due to the high importance of potato as a Figure 10 .4 .1 . Distribution of potato wild species and priority species for collecting. (a) Herbarium records (grey) and germplasm accessions (red) included in the analysis. (b) Species richness calculated on basis of environment niche models. Further information is available on the project website: http://www.cwrdiversity.org/ and in Castañeda-Álvarez et al. (2015). GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 89 staple food, Castañeda-Álvarez et al. (2016) assigned 10 .5 Gap analysis for potato landraces a high priority to the further collecting of potato of the ‘Andigenum group’ crop wild relatives and recommended gaps in potato collections be a priority focus before considering other Predicted gaps for Solanum tuberosum crops. ‘Andigenum group’ In a more detailed study, seven species of the primary Potato landraces have an estimated conservation gene pool, 63 species of the secondary and three dis- gap of about 50% (Ramirez-Villegas et al., 2022). To tant relatives of the tertiary gene pool were analyzed assess gaps in the geographical coverage of potato (Castañeda-Álvarez et al., 2015). In particular, scores landraces conserved ex situ, the gap analysis of for sampling representativeness, geographic repre- Ramirez-Villegas et al. (2020) was used as part of the sentativeness and ecosystem representativeness were work conducted by the CGIAR Genebank Platform analyzed on the basis of 49,164 records and revealed (CGIAR Genebank Platform, 2020). The potential that 32 species had large gaps in ex situ collections geographic distribution of landraces was modeled (Castañeda-Álvarez et al., 2016) (Figure 10.4.1). Of and compared with the geographical coverage of the these, four are endemic in Mexico, three in Bolivia, accessions conserved ex situ. For the spatial analysis two in Colombia, two in Ecuador and 21 in Peru, par- of potato landraces in the Americas, landraces of ticularly in the departments of Cajamarca, La Libertad, the ‘Andigenum group’ with accessible and georef- Ancash and Huánuco. Some of the high priority spe- erenced data (Table 10.5.1.1) were analyzed from cies occur in habitats that are highly threatened, such different collections (Figure 10.5.1.1a). Following the Solanum rhomboideilanceolatum Ochoa and Solanum approach of Ramirez-Villegas et al. (2020), gaps were piurae Bitter. A further combined analysis of future categorized as low-probability (gap found with one climate in production areas as well as climates in the approach), medium-probability (gap found with two native habitats of 72 wild potato species revealed that approaches) and high-probability (gaps found with the future climate scenarios for 26 species may be ben- three approaches). The final results showed that the eficial for future adaptation of potato varieties (Fumia potato landraces in collections cover about 73% of the et al., 2021). Overall, priorities should be assigned to geographic area where potato landraces are grown those species that are not yet present in ex situ collec- (Figure 10.5.1.1). Further analysis of the gaps in the tions, have a geographic importance in the center of countries of distribution revealed that most landraces diversity and are of importance for breeding. distributed in Guatemala (98%) were safely stored ex (a) Predicted distribuon (b) Predicted gaps no low medium high Probability of distribu on 1.0 0.5 0 Figure 10 .5 .1 .1. Predicted distribution and gaps of landraces of Solanum tuberosum ‘Andigenum group’. (a) Probability of distribution of landraces of S. tuberosum ‘Andigenum group’ according to the distribution model. (b) Location of the gaps found by this analysis. Probability gaps are colored in grey for low-probability gaps found with one approach, in orange for medium-probability gaps found with two approaches and red for high-probability gaps found with three approaches. Color code is given in the figures. 90 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO situ. In contrast, it was estimated that only 69%, 67%, than 0.05 (i.e. 5%) within a target ecogeographic 63%, 40% and 0% of the area where landraces are region without considering population genetics expected to occur in Ecuador, Paraguay, Peru, Chile and demographic parameters (Maxted et al., 2008). and Haiti, respectively, are covered by ex situ collec- Alternatively, allelic diversity can be estimated by tions (Table 10.5.1.2) DNA sequencing of the collections, and thus missing combinations and other gaps identified. Based on Composition and gaps of the CIP collection AFLP markers, Bamberg and Del Rio (2016) found that about 100 populations captured 95% of polymorphic The composition of the CIP (PER001) collections loci for wild potato species and provide a reasonable was analyzed by assigning the accessions of the threshold for the number of potato accessions needed S. tuberosum ‘Andigenum group’ to the groups in for each species. However, although DNA sequencing a potato diversity tree, a hierarchical stratification technologies are becoming cheaper, it is unlikely that of the potato gene pool into groups and subgroups 16,500 accessions of wild species and 18,500 accessions based on information from published literature and of landraces can be sequenced and data comprehen- expert opinion. The concept of the diversity tree was sively analyzed in the next few years. Due to habitat initially proposed by van Treuren et al. (2009). Based destruction and changes in land use, the likelihood on this concept, each row in Table 10.5.2.1 is a group of unique and important genotypes disappearing in the potato diversity tree and is expected to be increases daily and collecting missions are urgently represented in a global ex situ collection of potato needed now. genetic resources, such as PER001. Groups with no accessions at PER001 are gaps in the representation of Table 10 .5 .1 .1. Accessions used for the spatial analysis. When multiple accessions had the same coordinate data only one the potato genepool conserved ex situ at PER001. We was used for the analysis. also considered groups with fewer than 10 accessions to be poorly represented. Institute Accessions of Solanum tuberosum code (‘Andigenum group’ and ‘Chilotanum group’) According to these results, gaps of the tetraploid PER001 4069 (4x) landraces were found in Bolivia, in particular in BOL317 1566 the Tarija and Santa Cruz departments. For the same ITA406 1015 taxa, gaps were found in Ecuador, in the provinces of COL017 948 Pichincha, Napo, Tungurahua, Zamora-Chinchipe, and PER867 785 in Peru, in the departments of Arequipa, Moquegua, USA004 647 Piura, San Martin, and Tacna. However, in some acces- ROM007 321 sions, i.e. for 520 accessions of S. tuberosum ‘Andi- CHL071 242 genum group’ from Peru, the ploidy is unknown, so the analysis is incomplete. ESP172 75 NLD037 65 10 .6 Challenges and steps towards gap Other filling genebanks 426 Most European and Asian genebanks have a combi- Table 10 .5 .1 .2. Metrics of the Solanum tuberosum ‘Andi- nation of national, regional and international mate- genum group’ gap analysis. Analysis by country conducted by CIAT (2021). rial in ex situ conservation. Those that keep national varieties and heirloom varieties consider that there are no or only a few gaps in the population represen- Country Average estimated Coverage of area gap area [km²] where landraces are predicted to be found tation in their collections. In all genebanks, gaps were Peru 161000.5469 63% identified in the ex situ collections for South American landraces and wild species. Bolivia 107303.8418 76% Ecuador 19634.63501 69% Collection gaps might be filled by (1) exchanging and, Colombia 15846.59253 91% (2) developing germplasm or (3) collecting missions Chile 8195.315186 40% (Bamberg et al., 2018). For material that is not yet Argentina 2567.720459 84% present in genebanks, missions for collecting unique Mexico 1915.925018 91% material need to be carried out. This raises the ques- Brazil 259.2323303 74% tion what to collect first and where to go. As discussed Guatemala 123.0456352 98% in chapter 10.1, Marshall and Brown (1975) and Law- Haiti 60.86857605 0% rence et al. (1995) suggested that 50 or 172 accessions, respectively, may be generally sufficient to cover Venezuela 23.94531083 74% 95% of the alleles that occurs at frequencies higher Paraguay 12.03267717 67% GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 91 Table 10 .5 .2 .1. Number of Solanum tuberosum ‘Andigenum group’ accessions represented at PER001 in different groups of the diversity tree. Level of ploidy County Region Number of accessions at PER001 Andigenum group 4x Bolivia Chuquisaca 6 Andigenum group 4x Cochabamba 117 Andigenum group 4x La Paz 33 Andigenum group 4x Oruro 46 Andigenum group 4x Potosi 61 Andigenum group 4x Tarija 1 Andigenum group 4x Santa Cruz 0 Andigenum group 4x Argentina all 148 Andigenum group 4x Colombia all 118 Andigenum group 4x Ecuador Azuay 17 Andigenum group 4x Bolivar 15 Andigenum group 4x Carchi 28 Andigenum group 4x Canar 11 Andigenum group 4x Chimborazo 40 Andigenum group 4x Cotopaxi 28 Andigenum group 4x Imbabura 25 Andigenum group 4x Loja 25 Andigenum group 4x Napo 0 Andigenum group 4x Pichincha 5 Andigenum group 4x Tungurahua 3 Andigenum group 4x Zamora-Chinchipe 0 Andigenum group 4x Peru Amazonas 18 Andigenum group 4x Ancash 129 Andigenum group 4x Apurimac 91 Andigenum group 4x Arequipa 0 Andigenum group 4x Ayacucho 136 Andigenum group 4x Cajamarca 89 Andigenum group 4x Cusco 380 Andigenum group 4x Huancavelica 75 Andigenum group 4x Huánuco 78 Andigenum group 4x Junín 426 Andigenum group 4x La Libertad 29 Andigenum group 4x Lima 44 Andigenum group 4x Moquegua 0 Andigenum group 4x Pasco 57 Andigenum group 4x Piura 4 Andigenum group 4x Puno 121 Andigenum group 4x San Martin 0 Andigenum group 4x Tacna 0 Andigenum group 4x Venezuela 28 Andigenum group 4x Mexico 27 Andigenum group 2x Peru 247 Andigenum group 2x Bolivia 67 Andigenum group 2x Colombia 92 Andigenum group 2x Ecuador 65 Andigenum group 3x Peru 140 Andigenum group 3x Bolivia 26 Andigenum group 3x Colombia 18 Andigenum group 3x Ecuador 8 92 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Gap analysis is a tool that combines taxonomic, considerations show that gap analysis should be com- geographic, and ecological data and may also include plemented by other approaches to identify valuable information on genetic diversity, traits and threats genetic resources. and is used to compare the potential distribution of species with available accessions conserved ex situ. Overall, the following steps should be considered to Based on this approach Castañeda-Álvarez et al. (2015) successfully fill gaps in ex situ collections before popu- assigned a high priority to 32 wild species to be col- lations disappear in the wild. lected in Peru, Mexico, Bolivia, Colombia and Ecuador (Table 3.2.1). In addition, by adopting the modified Taxonomy. Use of an appropriate and universal tax- approach of Ramirez-Villegas et al. (2020), gaps in onomy that can be applied uniformly in the potato landraces of the S. tuberosum ‘Andigenum group’ collections. The identification of gaps is essentially were identified after the analysis of about 10,000 based on taxonomic classification and data correct- potato landraces from 10 different genebanks. Based ness. on a further comparison with the potato diversity tree, collection missions for tetraploid landraces are Passport data . Digitization and completion of pass- recommended in: Bolivia, in particular in the Tarija port data including GPS coordinates for the collection and Santa Cruz departments; Ecuador, in the provinces site(s) as a basis of further steps. of Pichincha, Napo, Tungurahua, Zamora-Chinchipe; and Peru, in the departments of Arequipa, Moquegua, Genetic information . Genotyping is needed for the Piura, San Martin, and Tacna. In addition, landraces identification of unique genotypes and can assist gap from Paraguay and Chile must also be considered. analysis. Efforts should be made to collect sequence data and link it to passport information in order to Although gap analysis is of great value, it assumes identify priorities. that the eco-geographic pattern can predict genetic diversity, and, therefore, that accessions from dif- Gap analysis can help in setting priorities and identi- ferent sites will increase the allelic diversity in the fying collection sites. collection. Del Rio and Bamberg (2002) investi- gated the genetic distance among populations and Sites to collect. Due to mutations, natural selection, compared it with geographical parameters such as genetic drift and gene flow, it is also important to latitude, longitude, elevation and distance. Unfortu- re-collect populations from in situ sites which may nately, no significant correlations were found for the already be in ex situ conservation. Cadima Fuentes populations of S. sucrense, S. fendleri and Solanum et al. (2017) observed significant genetic differences jamesii Torr. In another study, 152 RAPD markers were on the basis of RFLP markers between ex situ and in used to investigate the genetic distance of S. verru- situ conserved wild species. Further support from gap cosum populations. The genetic distance was found analysis and the experience of collectors is essential to to be significantly correlated with spatial separation identify hotspots and important habitats. (r = 0.4*), longitude (r = 0.5**) and latitude (r = 0.7). In addition, significant correlations were also iden- Experts . It is critical to identify and include the most tified with the closely related species S. hjertingii, knowledgeable expertise in collections and this Solanum hougasii Correll and S. demissum. Del Rio includes crop curators with intimate knowledge of the and Bamberg (2004) speculated whether the signif- species and crop as well as regional or local knowl- icant associations are based on introgressions from edge on where the material might be found. other species, which would affect the conservation value, or whether they are coincidentally related to Financial resources . Funding has been identified as a geographic determinants. However, gap analyses are key limitation for many of the genebanks and funding limited because they depend on the availability of cor- for collecting missions is particularly scarce globally rect and comprehensive data (Ramírez-Villegas et al., but most important for potato in South and central 2010), i.e. geographic, taxonomic, ecological, trait and American countries. Therefore, the international com- threat information. For crop wild relatives, this type munity needs to support collecting missions through of information may be insufficient. Voucher specimen international collaborations. in herbaria and other biological resources inventories play an important role in quantifying the complete- Local authorities . Obtaining legal permission to collect ness of in situ and ex situ collections but may be scarce has increasingly become a bottleneck. Thus, capacity (Maxted et al., 2008). In addition, the methodology building on Access and Benefit Sharing (ABS) needs is also limited by the models used and important to be strengthened for national authorities. Such information such as habitat quality and history are training must provide clear and easy to understand not integrated and can hardly predict variability of concepts and clarify legal issues. biotic elements. In any case, these studies and various GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 93 94 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Solanum tuberosum L. Seikei Zusetsu vol. 22 11P OTATO BREEDING AND USAGE OF THE COLLECTION The crops used for national food supplies have 11 .1 Historical aspects of potato become increasingly similar among countries over breeding the last 50 years (Khoury et al., 2014). At the same time, the genetic diversity within commercially grown Andean farmers were the first to domesticate and potatoes dates back to a few founder lines from the select potato genotypes for human consumption and 19th century, and has therefore not changed signifi- they have continued to improve potato resources to cantly in the last decades (Vos et al., 2015). Against the present time. Traditionally, the crop is planted the backdrop of global climate change, this could in heterogenous fields that include various varieties, pose serious problems for the potato industry and species and ploidy levels and may also be a mixture was the cause of the devastation the industry faced in of tubers from both clones and seeds. The benefits the 19th century. The integration of crop wild relatives of this well-established practice are that a) rejuve- and landraces into modern varieties is a well-known nation is integrated into the production system, b) a approach and it has been forecasted that potato mixture of flavors, textures, shapes and colors can be will benefit most from the integration of crop wild produced for different kinds of specific dishes, and c) relatives, especially in sub-Saharan Africa (Pironon et at least some plants are tolerant and can be harvested al., 2019). However, improved breeding strategies and even after exposure to various environmental stresses. technologies need to be used to overcome the cur- Under these conditions, very dynamic evolutionary rent limitations in potato breeding. Overall, greater processes have been supported, leading to new vari- integration of potato genetic resources into breeding eties and most likely new species (Quiros et al., 1992). concepts will help diversify our food system, increases the crop’s nutritional value and make the potato crop At the beginning of the 19th century, potato yields in more tolerant toward environmental and other future most parts of the world were generally very low, and challenges. previous year’s tubers were used for the next crop. The GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 95 Potato cross pollination. Photo: Michael Major/Crop Trust British botanist Thomas Andrew Knight began with inhibits pollen tube growth in the upper first third of the first crossing trials in 1810 but targeted breeding the style (Figure 11.2.1 b). In self-incompatible species, was not considered until the late blight epidemics the RNase activity is 100 to 1,000-fold higher than seriously damaged potato production in Europe and in self-compatible genotypes of Nicotiana tabacum the USA. At this time, the US botanist Chauncey E. (McClure et al., 1989). The male/pollen S-determinant Goodrich imported plants from Chile and conducted contains pollen-expressed F-box genes. The S hap- the first undirected crossing trials. As a result, the lotype-specific F-box proteins (SLFs) show sequence newly selected lines, i.e. ‘Garnet Chili’, ‘Purple Chile’ polymorphisms which were comparable to that of and ‘Early Rose’, were superior to other US varieties the S-RNAs. The SLFs encode F-box proteins that can, and were released. The US botanist Luther Burbank among other things, compose a class of ubiquitin continued to select from open-pollinated plants from ligase (Ushijima et al., 2003) that detoxify the non-self ‘Early Rose’ and released the famous varieties ‘Bur- S-RNases, the allelic products of the pistil determinant, bank’ and ‘Russet Burbank’ in 1876, which became and allow compatible pollinations (Kubo et al., 2010). the most important varieties in the USA and Canada Overall, loss-of-function of S-RNAse is essential to and are still grown today (Jansky and Spooner, 2018). introduce non-self SLFs and conferring self-compati- In Europe, the Scottish botanist William Patterson bility in Solanaceae. and the Dutch Geert Veenhuizen initiated systematic crossing and breeding programs, releasing the first In the wild diploid S. chacoense, the dominant S-locus varieties ‘Victoria’ in 1856 (Stuart 1937) and ‘Eigen- inhibitor (Sli) gene (Hosaka and Hanneman, 1998a) heimer’ in 1888 (De Haan, 1958). Although these sys- located on chromosome 12 controls self-compatibility tematic breeding approaches faced low male fertility and can be considered as a dominant gain of function in Europe and the USA, more than 350 varieties were (Hosaka and Hanneman, 1998b). Recent research has released by the end of the 19th century (Hougas and shown that Sli is able to interact with multiple allelic Ross, 1956). variants of the pistil-specific S-RNases and overcome self-incompatibilities (Eggers et al., 2021; Ma et al., Through hybridising of inbred lines, further self-pol- 2021). Subsequently, several self-pollination events lination and selection within the progeny, modern showed that vigorous, fertile clones with high homo- potato breeding began in the early 20th century zygosity levels can be produced (Hirsch et al., 2013). (Jansky and Spooner, 2018). In particular, the use of exotic germplasm marked an important event in Unilateral incompatibility and stylar barriers . The introducing resistance to viruses, bacteria and nema- second pre-zygotic hybridization barrier acting at todes (Bradshaw et al., 2006). However, yield has not the pollen-pistil level is cross-incompatibility (Maune increased significantly over the last 100 years (Douches et al., 2018). As hybrid zygote formation is possible et al., 1996) and analysis of allele frequencies showed after crossing fertile plants in one direction, it is that most SNPs had hardly changed (Vos et al., 2015). termed unilateral. Commonly, the self-incompatible Douches et al. (1996) speculated that this is due to (SI) species can be used as a pollinator of the self-com- the narrow genetic bases used, the inefficiency of patible (SC) species and produce fertile F1 plants but breeding strategies and the diversity of quality traits reciprocal crosses are usually not successful (Jansky needed to meet the requirements of the processing and Hamernik, 2009). When the SI species is used as a industry and consumers. Nevertheless, potato breeders female plant, the pollen tube growth is arrested in the managed to maintain a high degree of polymorphism upper, middle or bottom part of the style or even in and promote positive chromosomal rearrangements the ovary (Figure 11.2.1 c-e). Due to the unilateral, but associated with resistance genes, e.g. resistances to also in some cases bilateral, incompatibility with dif- Globodera rostochiensis (Vos et al., 2015). However, ferent reaction sites, cross-incompatibility cannot be the limitations in fixing beneficial alleles due to the completely explained by the S-locus or the S-haplotype tetraploid nature of the crop need to be overcome in (Maune et al., 2018). However, it is also possible for future. breeders to find exceptional plants that overcome the unilateral incompatibility crossing barrier and allow 11 .2 Genetic hurdles in potato breeding interspecific crosses as demonstrated by Eijlander et al. (2000) for S. verrucosum. Self-incompatibility is common for most diploid tuber-bearing Solanum species (Spooner et al., 2014) Male sterility. In contrast to most diploid wild potato and is controlled by the S-locus on chromosome 1 species, tetraploids are self-compatible. However, due (Rivard et al., 1996). This polymorphic locus functions to the continuous selection pressure for tuber yield as a gatekeeper and produces an S-RNase (Luu et al., and quality, recessive sterility alleles can accumulate 2000). The S-RNase of the female- /pistil S-determinant in cultivated potatoes (Jansky and Thompson, 1990). encodes the primary amino-acid sequence of S—gly- Cytoplasmic-genetic male sterility has frequently coproteins that is cytotoxic (McClure et al., 1989) and been detected in hybrid plants of crosses between 96 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO cultivated and wild potatoes (Larrosa et al., 2012). on the observation that endosperm develops normally Interspecific crosses of haploid plants of the ‘Chi- when paternal:maternal gene ratio is 1:2 (Johnston et lotanum group’ and clones of the ‘Andigenum group’ al., 1980) (Figure 11.2.2 a, b). EBNs for different spe- also produce sterile plants when haploids were the cies are assigned arbitrary values and are determined female parent (Carroll, 1975). Male sterility in di-hap- based on the crossing behavior of the species com- loids obtained from tetraploids is also a major barrier monly with S. chacoense (Ortiz and Ehlenfeldt, 1992). for use in breeding. However, in a few cases, when Hanneman (1993) assigned tuber-bearing Solanum male-fertile diploids can be obtained, the generation species and their close relatives to EBN numbers of a higher frequency of male fertility is likely (De (Table 3.2.1) and revealed that most North American Maine, 1997) and breeding programs can be initiated. diploids, tetraploids and hexaploids are 1EBN, 2EBN and 4EBN, respectively. By contrast, South American Endosperm Balance Numbers (EBN). Endosperm diploids and tetraploids species are 2EBN and 4EBN development is essential for production of viable and but hexaploids are 4EBN. Therefore, species are iso- vigorous seed and partly explains the difficulties in lated from each other due to the EBN differences, and crossing between species of the Petota section. Inter- this in part explains the challenges in crossing North specific crosses and intraploidy can provoke endo- and South American species. Similarly, the production sperm failure. Thereby, the EBN hypothesis is based of triploids via crossing of di- and tetraploid material Figure 11 .2 .1 . Pollen-tube growth after intra- and interspecific crossing events of accessions of the wild diploid potatoes Solanum chacoense Bitter, Solanum gourlayi Hawkes and Solanum spegazzinii Bitter and Solanum tuberosum. (a) Pollen-pistil compatibility was shown for most genotypic combinations. (b) Incompatibility at the top was present after selfing of the diploid genotypes. (c, d) Incompatibility at the middle and (e) bottom of the style was characteristic for cross-incompatibility. Scale bars = 0.1 cm. Source: Maune et al. (2018) (a) (b) (c) Pollen Sgma Seed Testa 1EBN 2EBN 4EBN Endosperm 3x 1x Embryo2x Cotyledones 1x 2x Radicle SC SI SC SI Sperm nuclei Micropylar 2) 1x gel (2 02 . N a Egg cell endosperm M 1 2 3 4 5 Figure 11 .2 .2 . Endosperm Balance Number (EBN) and its implication for breeding. (a) Paternal:maternal gene ratio of 1:2 in the endosperm results in (b) successful hybridization and development of fertile seeds, adapted from Johnston et al. (1980). (c) Crossability groups based on the EBN and sexual compatibility (SC) or incompatibility (SI); based on Spooner et al. (2014). GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 97 results in an imbalance of the ratio (4:1) and, con- degree of ploidy, Jansky et al. (2013) considered that sequently, a failure in the endosperm development hexaploid (6x, 4EBN), tetraploid (4x, 4EBN or 4x, EBN) (Ortiz and Ehlenfeldt, 1992). Hence, these numbers and some diploid (2x, 2EBN) species can be cate- have predictive power for the success or failure of gorized in the primary gene pool and most diploid interspecific crosses, the ploidy of the progeny and species (2x, 1EBN) belong to the secondary gene pool. provide also implications for improvements in potato Spooner et al. (2014) proposed the inclusion of infor- breeding. mation about self-compatibility/incompatibility and the five crossability groups suggesting (Figure 11.2.2 11 .3 Potato gene pools and use of wild c) where crossability between the groups is less likely. species Based on this, Castañeda-Álvarez et al. (2015) assigned most wild species to the different gene pools (Table The gene pool concept was established by Harlan and 3.2.1, Figure 11.3.1). Overall, seven species, including de Wet (1971) and describes the degree of relatedness S. acaule, S. berthaultii, S. brevicaule, S. candolleanum, between wild species and crops. Gene pools can be belong to the primary gene pool. In addition, 62 spe- differentiated between primary, secondary and ter- cies were assigned to the secondary gene pool and 24 tiary gene pool. Species of the primary gene pool are to the tertiary gene pool. closely related and can generally be directly crossed to cultivated varieties. The hybrids produced from such Vincent et al. (2013) applied the gene pool concept to crosses generally show normal meiotic chromosome potato and prioritized 88 wild relatives as requiring pairing, are vigorous and fertile. To achieve hybrids by global conservation. About 43 of the 88 wild rela- crossing wild relatives from the secondary gene pool, tives are reported to have been either confirmed or additional biotechnological techniques, e.g. embryo of potential use in crop breeding and improvement rescue, might be required and products may have (Table 11.3.1). reduced fertility. Species of the tertiary gene pool are generally not crossable and require additional 11 .4 Breeding strategies and technologies to enable gene transfer. For breeding approaches and introgression of favourable alleles into the crop, species of the primary and secondary gene pool are Most potato breeding programs use complementary mostly used (Maxted et al., 2012). parental lines of cultivated S. tuberosum for inter- mating and select best combinations based on the In potato, pre- and postzygotic barriers to hybridiza- progeny. By further selection processes over several tion are a challenge to categorize the gene pools. One generations, phenotypes showing desirable traits and determinant of success for interspecific hybridization yields are released as varieties (Sood et al., 2017). is the EBN (Johnston et al., 1980). Based on EBN and However, the narrow genetic base of cultivated potato Solanum acroglossum Juz. Ter�ary Solanum iopetalum (Bi�er) Hawkes Solanum acroscopicum Ochoa Solanum kurtzianum Bi�er & Wi�m. gene pool Secondary Solanum agrimonifolium Rydb. Solanum laxissimum Bi�er Solanum albornozii Correll Solanum lesteri Hawkes & Hjert. gene pool Solanum andreanum Baker Solanum limbaniense Ochoa Solanum pinnatisectum Dunal Solanum ayacuchense Ochoa Solanum lobbianum Bi�er Solanum anamatophilum Ochoa Solanum boliviense Dunal in DC. Solanum longiconicum Bi�er Solanum augustii Ochoa Solanum bombycinum Ochoa Solanum maglia Schltdl. Solanum bulbocastanum Dunal in Poir. Solanum buesii Vargas Solanum medians Bi�er Solanum cardiophyllum Lindl. Primary Solanum burkartii Ochoa Solanum microdontum Bi�er Solanum commersonii Dunal Solanum cajamarquense Ochoa Solanum morelliforme Bi�er & Muench Solanum dolichocremastrum Bi�er gene pool Solanum cantense Ochoa Solanum multiinterruptum Bi�er Solanum ehrenbergii (Bi�er) Rydb. Solanum chacoense Bi�er Solanum neocardenasii Hawkes & Hjert. Solanum humectophilum Ochoa Solanum chilliasense Ochoa Solanum neorossii Hawkes & Hjert. Solanum hypacrarthrum Bi�er Solanum acaule Bi�er Solanum chiquidenum Ochoa Solanum neovavilovii Ochoa Solanum immite Dunal Solanum berthaultii Hawkes Solanum chomatophilum Bi�er Solanum nubicola Ochoa Solanum jamesii Torr. Solanum brevicaule Bi�er Solanum clarum Correll Solanum olmosense Ochoa Solanum lignicaule Vargas Solanum candolleanum Berthault Solanum colombianum Dunal Solanum oxycarpum Schiede Solanum malmeanum Bi�er Solanum infundibuliforme Phil. Solanum contumazaense Ochoa Solanum paucissectum Ochoa Solanum minutifoliolum Correll Solanum okadae Hawkes & Hjert. Solanum demissum Lindl. Solanum pillahuatense Vargas Solanum mochiquense Ochoa Solanum vernei Bi�er & Wi�m. Solanum flahaultii Bi�er Solanum piurae Bi�er Solanum raquialatum Ochoa Solanum gandarillasii Cárdenas Solanum polyadenium Greenm. Solanum scabrifolium Ochoa Solanum garcia-barrigae Ochoa Solanum raphanifolium Cárdenas & Hawkes Solanum simplicissimum Ochoa (1989b) Solanum gracilifrons Bi�er Solanum rhomboideilanceolatum Ochoa Solanum stenophyllidium Bi�er Solanum guerreroense Correll Solanum salasianum Ochoa Solanum tarnii Hawkes & Hjert. Solanum hastiforme Correll Solanum schenckii Bi�er Solanum trifidum Correll Solanum hintonii Correll Solanum sogarandinum Ochoa Solanum trinitense Ochoa Solanum hjertingii Hawkes Solanum stoloniferum Schltdl. Solanum wittmackii Bi�er Solanum hougasii Correll Solanum venturii Hawkes & Hjert. Solanum huancabambense Ochoa Solanum verrucosum Schltdl. M. Nagel (2022) Solanum incasicum Ochoa Solanum violaceimarmoratum Bi�er Figure 11 .3 .1: Species of the Petota group assigned to primary, secondary and tertiary gene pool. Based on data of Castañeda-Álvarez et al. (2015). 98 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Table 11 .3 .1 . Potential uses of wild potato species. Confirmed uses are in bold and potential are in regular text. Data source: Harlan and de Wet Inventory (https://www.cwrdiversity.org/checklist/ accessed on 05th November 2020). Scientific Name Gene pool concept Type of use Confirmed or potential use Solanum acaule Primary Abiotic stress Frost Tolerance; Drought tolerance; Heat tolerance Potato Virus X resistance; Blackleg and soft rot resistance; Cyst Nematode Biotic stress Resistance; Early Blight resistance; Fusarium wilt resistance; Potato leaf roll virus resistance; Potato virus Y resistance; Spindle Tuber viroid resistance; Wart resistance Solanum ajanhhuiri Abiotic stress Frost tolerance Blackleg and soft rot resistance; Verticillium resistance; Aphid resistance; Solanum berthaultii Primary Biotic stress Colorado potato beetle resistance; Cyst nematode resistance; Early blight resistance; Late blight resistance; Potato virus X resistance; Potato virus Y resistance; Spindle Tuber viroid resistance; Wart resistance Quality trait Cold induced sweetening resistance Abiotic stress Drought tolerance; Frost tolerance; Heat tolerance Solanum boliviense Secondary Abiotic stress Drought tolerance; Frost tolerance; Heat tolerance Biotic stress Blackleg and soft rot resistance; Cyst nematode resistance; Wart resistance Solanum brevicaule Primary Agronomic trait Percentage dry matter Cyst nematode resistance; Globodera pallida resistance; Bacterial wilt; Biotic stress Blackleg and soft rot resistance; Fusarium wilt resistance; Potato virus X resistance; Potato virus Y resistance; Root knot nematode resistance; wart resistance Abiotic stress Drought tolerance; Frost tolerance; Heat tolerance Solanum Late Blight resistance; Root knot nematode resistance; Aphid resistance; bulbocastanum Tertiary Biotic stress Blackleg and soft rot resistance; Cyst nematode resistance; Early blight resistance Abiotic stress Drought tolerance; Heat tolerance Solanum candolleanum Primary Abiotic stress Blackleg and soft rot resistance; Drought tolerance; Frost tolerance; Heat tolerance Biotic stress Aphid resistance; Verticillium wilt resistance Solanum cardiophyllum Tertiary Biotic stress Cyst nematode resistance; Late blight resistance; Root knot nematode resistance Solanum chacoense Secondary Agronomic trait Percentage dry matter Blackleg and soft rot resistance; Verticillium wilt resistance; Bacterial wilt; Colorado potato beetle resistance; Common scab resistance; Early Blight Biotic stress resistance; Late Blight resistance; Potato leaf roll virus resistance; Potato virus X resistance; Potato virus Y resistance; Root Knot nematode resistance; tuber moth resistance Quality trait Cold induced sweetening resistance Abiotic stress Drought tolerance; Heat tolerance Solanum chomatophilum Secondary Abiotic stress Frost tolerance Biotic stress Aphid resistance Solanum circaeifolium Tertiary Biotic stress Cyst nematode; Late blight resistance Solanum commersonii Tertiary Abiotic stress Drought tolerance; Frost tolerance; Heat tolerance Biotic stress Blackleg and soft rot resistance; Colorado potato beetle resistance; Common Scab resistance; Potato virus X resistance Solanum curtilobum - Abiotic stress Frost tolerance Biotic stress Potato virus X resistance; Root knot nematode resistance Late blight resistance; Potato Leaf Roll virus resistance; Blackleg and soft Solanum demissum Secondary Biotic stress rot resistance; Colorado potato beetle resistance; Cyst nematode resistance; Late Blight resistance; Potato virus Y resistance; Wart resistance Abiotic stress Frost tolerance Solanum edinense - Biotic stress Late blight resistance Solanum etuberosum Tertiary Abiotic stress Frost tolerance Biotic stress Potato leaf roll virus resistance Solanum guerreroense Secondary Biotic stress Spindle Tuber viroid resistance GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 99 Scientific Name Gene pool concept Type of use Confirmed or potential use Solanum hjertingii Secondary Biotic stress Blackleg and soft rot resistance; Root knot nematode resistance; Spindle tuber viroid resistance Solanum hougasii Secondary Biotic stress Late blight resistance; Root knot nematode resistance; Potato virus Y resistance Solanum infundibuliforme Primary Biotic stress Aphid resistance Solanum iopetalum Secondary Biotic stress Late blight resistance Solanum jamesii Tertiary Biotic stress Colorado potato beetle resistance; Common scab resistance Solanum juzepczukii – Abiotic stress Frost Tolerance Biotic stress Potato Virus X resistance Solanum kurtzianum Secondary Biotic stress Cyst nematode resistance; Fusarium wilt resistance; Root knot nematode resistance Solanum lignicaule Tertiary Biotic stress Aphid resistance Solanum marinasense Primary Biotic stress Aphid resistance Solanum medians Secondary Biotic stress Aphid resistance Quality trait Chip making from cold Solanum microdontum Secondary Abiotic stress Drought tolerance; Heat tolerance Biotic stress Bacterial wilt; Blackleg and soft rot resistance; Late blight resistance; Root knot nematode resistance Solanum mochiquense Tertiary Biotic stress Late Blight resistance Solanum multiinterruptum Secondary Abiotic stress Frost tolerance Biotic stress Aphid resistance; Cyst nematode resistance; Spindle tuber viroid resistance Solanum neocardenasii Secondary Biotic stress Aphid resistance Solanum okadae Primary Quality trait Chip making from cold Solanum palustre Tertiary Biotic stress Potato leaf roll virus resistance; Blackleg and soft rot resistance Abiotic stress Frost tolerance Solanum pinnatisectum Tertiary Abiotic stress Drought tolerance; Heat tolerance Biotic stress Blackleg and soft rot resistance; Colorado potato beetle resistance; Late blight resistance Quality trait Chip making from cold Solanum polyadenium Secondary Biotic stress Colorado potato beetle resistance; Late blight resistance Solanum raphanifolium Secondary Quality trait Cold induced sweetening resistance; Chip making from cold Abiotic stress Frost tolerance Biotic stress Potato leaf roll virus resistance; Verticillium wilt resistance Solanum sogarandinum Secondary Quality trait Chip making from cold Solanum stoloniferum Secondary Biotic stress Late blight resistance; Potato virus Y resistance; Aphid resistance; Potato leaf roll virus resistance Abiotic stress Drought tolerance; Heat tolerance Solanum tarnii Tertiary Biotic stress Late blight resistance; Potato virus X resistance; Colorado potato beetle resistance; Bacterial wilt; Blackleg and soft rot resistance; Common scab resistance; Cyst Solanum tuberosum nematode resistance; Late blight resistance; Potato leaf roll virus resistance; subsp. andigena - Biotic stress Potato virus X resistance; Potato virus Y resistance; Root knot nematode resistance; Tuber moth resistance; Wart resistance Quality trait Ascorbic acid content; Carotenoid content; Cold induced sweetening resistance; high starch content; protein content Solanum venturii Secondary Biotic stress Late blight resistance Solanum vernei Primary Abiotic stress Frost tolerance Biotic stress Cyst nematode resistance; Verticillium wilt resistance; Blackleg and soft rot resistance; Late Blight resistance; Potato virus Y resistance; Wart resistance Quality trait Cold induced sweetening resistance; high starch content; protein content Solanum verrucosum Secondary Biotic stress Late blight resistance 100 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO has limited advancements in potato yield over the this is usually not feasible, a random combination of years (Douches et al., 1996). The different levels of crosses is usually analyzed. In the line x tester design, genetic hurdles (see chapter 11.2), especially self-in- different lines are crossed with one or more testers compatibility within the diploids and inbreeding and the progeny of full siblings are further evaluated, depression of the di- and tetraploids, are the major e.g. in randomized block designs. Design II is compa- challenges in fixing favorable alleles in the next rable to the diallel mating design although it includes generations. When further wild species and landraces all possible combinations. All of the designs show are crossed, many undesirable alleles, e.g. for deep advantages and disadvantages; and sterility barriers eyes, small tuber size, short-day adaptation, and high and incompatibilities during systematic matings can be glycol-alkaloid content, will need to be eliminated by a challenge. backcrossing. This process can take decades. Newer technologies, i.e. CRISPR-Cas9 technologies or mark- Estimated breeding values . In contrast to the parental er-assisted breeding, may speed up the processes value, which predicts the ability of a parental line to (Bonierbale et al., 2020), but may still be hampered by transmit desired alleles to the offspring, the estimated the aforementioned problems, i.e. incompatibilities, breeding value allows the modeling of underlying infertility, differences in ploidy, and the acceptance random effects and error components of variance. By of genetically modified organisms (GMOs). However, applying mixed models, i.e. best linear unbiased pre- some current promising breeding strategies and diction (BLUP), the genetic gain can be increased for approaches are listed below, following Bonierbale et traits with low heritability. This concept has been suc- al. (2020). cessfully transferred from animal breeding to various crops and should be carefully examined in the future. Population improvement by open recurrent selection . The basic idea is to improve the average performance Early versus late generation selection . Comparison of of a population by retaining and enhancing genetic breeding lines can be carried out at earlier breeding variation through systematic and regular introduc- stages, i.e. phenotyping of a few plants for highly tion of new material. Therefore, pre-bred plants with heritable traits, or at later breeding stages when more desired traits are periodically intermated into a pop- seeds/plants are available. Economically important ulation. Plants produced are re-selected and used for traits in potato are commonly complex traits involving recombinant populations for the next cycle. In poly- interplant competition, which may require block ploid potato, more than one allele per locus is usually designs and homogenous field conditions. The trait transferred. However, over time, linkage blocks are of interest and the available number of plants deter- commonly destroyed and desired traits maintained in mine the decision on early to later stages of selection, the germplasm. Depending on the population stage, including the specific designs involving adequate some of the selected material can be used as varieties. number of blocks and replicates. Crossing parents. The result from crossing tetraploid Breeding using diploids . Diploid potato varieties, parental potato lines is hardly predictable as dom- especially those of the ‘Phureja Group’, have long inance and epistatic effects determine the clonal been used by farmers in the Andes. For breeding tet- performance. However, to increase the predictability raploids, desirable diploid clones are usually screened, of a cross and to select the best parents, parental tested, selected and vegetatively multiplied and by values can be assigned. The parental value can be combining 2n gametes from the female and male determined by progeny testing using suitable designs, parent important alleles are fixed faster. To avoid by evaluating the pedigree or by observing selection problems, the genetic loci of male- and female-de- ratios. Additional information about trait variance, rived clones must complement each other, so that del- covariance, heritability, and additive and dominance eterious recessive alleles are not harmful (Bradshaw, variation allows the estimation of genetic effects and 2022). Compared to the F1 hybrids for TPS production, parameters and increases the chance to select best diploids lines can be still heterozygous. Recently, more parental lines. and more potato breeding companies are investing time and efforts in developing diploids that use their Mating designs. To determine genetic parameters, advantageous alleles for further introgression (per- parental values and to identify superior progenitors, sonal communication Richard Visser, 2022). systematic crosses of plants need to be carried out. Depending on the number of factors, parents and True hybrid potato breeding . The principal idea of modalities, different designs can be applied. The most hybrid potato breeding is more than 60 years old and common designs are the diallel mating design, line x aims at combining the advantages of true potato tester design, design II. Briefly, as described by Bonier- seed, diploid genetics and homogeneous parental bale et al. (2020) the diallel mating design refers, in lines. However, acceptable agronomic performance principle, to all possible combinations of crosses. Since of homozygous potato have not been present for a GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 101 long time (Lindhout et al., 2011). The main problem is clones that were subjected to chromosome doubling that about 20 of the 39,000 protein-encoding genes (Paz and Veilleux, 1997). After sequencing, the final (Potato Genome Sequencing et al., 2011) have severe assembly covered about 86% of the potato genome fitness effects. The odds of producing a vigorous with 844 Mb and some 39,000 genes predicted. The diploid progeny that is heterozygous at these 20 loci sequence of DM was compared with the heterozygous is only 0.3%. Heterozygous tetraploid plant material diploid potato genome (RH89–039-16, short RH) that has a higher chance of masking the effects of the had a high degree of heterozygosity. Only 55% of the unfavourable alleles (Lindhout et al., 2011). Although RH genome could be aligned to the DM genome and tetraploids usually have higher yields, some diploids potentially deleterious mutations occur frequently and are compatible with the tetraploid standards (Hutten are a likely cause of inbreeding depression (Potato et al., 1995). Genome Sequencing et al., 2011). A hybrid breeding system could allow systematic Further genome developments. To improve the incorporation of new genes, traits and the possibility genome assembly and its applicability for potato of substantial yield increases through crossing well-de- breeding, marker analysis of a backcross segrega- fined heterotic groups. In addition, low multiplication tion population of DD x (DM x DD) and in silico rates of clonally propagated tubers can be avoided by anchoring approaches were used along with physical producing true seeds from uniform F1 hybrid plants, and genetic maps from RH and tomato. DD was a including further beneficial effects of true potato heterozygous clone of the S. tuberosum ‘Andigenum seeds, i.e. low pathogen accumulation and higher Group’ (Sharma et al., 2013). Based on the sequencing storability. Major challenges are self-incompatibility in information, the Coordinated Agricultural Project inbred lines (Bonierbale et al., 2020) and inbreeding (SolCAP) developed the Infinium 8303 Potato Array depression caused by recessive deleterious mutations that allowed genetic mapping of numerous geno- (Charlesworth and Willis, 2009). However, Hosaka and types. Two mapping populations (DRH and D84) using Hanneman (1998a; 1998b) discovered that the intro- DM as female parent showed that over 4,400 markers gression of the Sli gene from S. chacoense can alter were mapped. The genetic maps covered 965 cM self-incompatibility and allow the production of selfed (DRH) and 792 cM (D84), respectively, and about 87% diploid potato seed. The second obstacle was recently of the genome sequence length (Felcher et al., 2012). overcome by implementing a genome design involving In 2015, based on the Infinium 8303 Potato Array and sequencing, analysis of haplotype information and the sequencing data of six varieties, the 20 K Infinium assessment of genome homozygosity, the number of SNP array became available (Vos et al., 2015) and has deleterious mutations and final selection of beneficial been further developed into the Infinium 22K V3 alleles. After analysing the genome complementary of Potato array (Pandey et al., 2021) by using additional inbred lines, the parental lines for vigorous F1 hybrids SNP marker data of the three varieties (Hamilton et were selected. The end product was the production of al., 2011). Furthermore, the draft genome of the wild F1 hybrid tubers showing strong heterosis and yield species S. commersonii, which diverged from potato potential comparable to tetraploid varieties (Zhang et about 2.3 million years ago, was published. Com- al., 2021). pared to the potato genome, the draft assembly had a similar size (830 Mb) but showed significantly less Basic requirements for future developments, i.e. heterozygosity and provided valuable insights into estimated breeding value, marker-assisted selec- evolutionary changes and environmental adaptation tion and true hybrid potato breeding, are a deeper (Aversano et al., 2015). Further sequencing efforts understanding of the potato genome, including the complement information about cultivated potato and availability of genetic resources and linked sequencing wild species and are listed below: information. 1. DArT marker-based linkage map for the wild potato Solanum bulbocastanum Dunal in Poir. (Iorizzo et 11 .5 Sequencing information al., 2014) 2. Genome assembly of the diploid inbred clone (M6) The potato reference genome of S. chacoense, with 882 Mb genome, 37,740 func- tionally annotated genes (Leisner et al., 2018) First potato genome . Sequencing heterozygous 3. Genome assembly and annotation of the heterozy- tetraploid plant material such as cultivated potato gous diploid potato RH89–039-16, 1.67 Gb haplo- has been a major challenge. Therefore, the potato type- resolved assembly, 10,642 annotated genes germplasm DM BARD 1–3 516 R44 (DM) (Veilleux, (Zhou et al., 2020) 2017), homozygous for a single set of the 12 chro- 4. Long-read reference genome assembly for potato mosomes was used to develop a reference genome. DM1–3 516 R44, the doubled monoploid clone of These monoploids were developed from heterozy- S. tuberosum ‘Group Phureja’, 742 Mb genome gous adapted Solanum tuberosum group Phureja assembly, 44,851 functionally annotated genes 102 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO (Pham et al., 2020) Genotyping of potato genetic resources 5. Bacterial artificial chromosome (BAC) libraries of the tetraploid potato varieties C88 was used to Genome sequencing and marker genotyping are the establish a physical map of target regions (Yang et basis of emerging strategies in the molecular breeding al., 2020) of polyploid plants by identifying potential genes for 6. Assemblies of 12 potato landraces varying in ploidy resistance and tolerance against abiotic and biotic levels (2x to 5x) (Kyriakidou et al., 2020) stresses, and can also assist in identifying unique 7. Assemblies of the somatic hybrid P8 (J1), the accessions in potato collections. The analysis of genetic wild species Solanum pinnatisectum Dunal (J2), identity is an important tool to reveal the genetic progeny MSH/14–112 (P8 × cv. ‘Kufri Jyoti’) (J3), and diversity within collections and to identify duplicates S. tuberosum dihaploid C-13 (J4), assembly size and unique material at local and global levels. between 725 (J1-J3) and 810 MB (J4) (Tiwari et al., 2021a) Based on the survey data provided by 32 genebanks, 8. Chromosome-scale assembly of the variety ‘Otava’, only two collections (PER001; IRL036) have fully 3.1 Gb haplotype-resolved, 38,214 genes (Sun et al., genotyped their potato germplasm, but 20 collec- 2021) tions have been partly genotyped (Figure 11.5.2.1). 9. Pan genome assemblies of six varieties used Unfortunately, data are only publicly available from for fresh (‘Colomba’, ‘Spunta’), chip processing 10 genebanks so far. Simple sequence repeat (SSR) ‘Atlantic’), frozen processing (‘Castle Russet’) and markers, also known as microsatellites, have been starch markets (‘Altus’, ‘Avenger’) were constructed, used most frequently in the past. More recently, single 3.1 Gb (Hoopes et al., 2022) nucleotide polymorphisms (SNPs) using genotyp- ing-by-sequencing (GBS) or the SolCAP 8K, 12K or 20K Accessibility of genetic information . The development Infinium array have been adopted (Illumina Inc., San of the various genetic resources including SolCAP Diego, USA). Some eight genebanks have not yet gen- Diversity Panel with phenotypic and genetic data from otyped their germplasm and two collections are in the 250 potato clones (Hirsch et al., 2013), was accompa- planning stage. Therefore, the following information nied by the need to improve the accessibility of com- provides only a partial overview and cites important plete information. In 2013, the following resources and recent peer-reviewed manuscripts. More detailed were available, and they still are: and up-to-date information can be obtained directly 1. the Solanaceae Source provides taxonomical infor- from the potato curators. mation 2. SolEST provides EST marker information for Solana- Asia . Japanese germplasm (JPN183) is specifically ceae species (D’Agostino et al., 2009) screened for the potato cyst nematode (Asano et al., 3. PlantGDB includes transcript data (Duvick et al., 2012). The pale potato cyst nematode Globodera pal- 2007) lida (Stone) Behrens. was first found in Japan in 2015. 4. KaPPA-View4 SOL presents metabolic pathways () Therefore, a screening of over 1,000 Japanese germ- 5. the PoMaMo database contains potato genetic plasm accessions was initiated and potential resistant maps and sequences varieties were identified (Asano et al., 2021). In China, 6. SolRgene provides information and search func- tion on disease resistance genes in tuber-bearing Solanum species (Vleeshouwers et al., 2011) 25 7. the Potato Pedigree Database houses pedigree information for potato varieties 20 AFLPs However, to centralise potato-specific information 15 SSRs and to share genome sequence of the Potato Genome not yet DArTs Sequencing Consortium (PGSC), the database Spud accessible 10 GBS planned DB was established providing associated annotation SolCAP 8K data and linked large-scale potato datasets as well as SolCAP 12K 5 powerful search tools to identify genes and regions of not SolCAP 20K interests. In addition, a Breeder’s Assistant was devel- planned published oped to provide genotypic and phenotypic data linked 0 Genotyping to the SolCAP potato 8303 Infinium SNP array (Hirsch No Yes method et al., 2014). Altogether, the databases, including Figure 11 .5 .2 .1. Status of genotyping in potato collections available sequencing, taxonomic and multiomic infor- of the 32 genebanks participating in the survey. AFLP, mation, represent key sources for the characterization Amplified Fragment-Length Polymorphism; DArT, Diversity and genotyping of potato varieties and plant genetic Array Technology; SSR, Simple sequence repeat, SNPs, single nucleotide polymorphisms analyzed by genotyping-by- resources. sequencing (GBS) or using different arrays (SolCAP 8K – 20K). GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 103 Number of genebanks there is a common interest to improve the genepool La Palma and Spain to identify unique alleles that they for future breeding programs, therefore several may date back to the first introduction of potato in research groups have initiated genotyping of local Europe (de Galarreta et al., 2011). varieties and material from local genebank collections (Wang et al., 2019). International collection (PER001) . The potato germ- plasm collection at CIP has been intensively genotyped Europe . The European collections have different goals, over the years and some results are summarized in i.e. conservation, breeding, working, reference collec- Ellis et al. (2020). The cultivated and wild potato col- tion (Figure 11.7.1). Therefore, genotyping of the col- lections have been partially genotyped with Ampli- lections is related to different topics. To assess genetic fied Fragment-Length Polymorphism (AFLP) and SSR diversity in the Nordic potato collection (SWE054) markers, i.e 1,000 landrace accessions (Ghislain et al., and between breeding lines, 133 potato accessions, 2004) or 742 landraces and some wild progenitors varieties and breeding clones typically grown under (Spooner et al., 2007). Furthermore, the entire culti- long daylength in Europe were genotyped using the vated collection has been genotyped with the SolCAP Infinium Illumina 20K SNP array. The results indicated 12K array. Genotypic information from 250 accessions that the background of all genotyped material is very was compared between plants maintained in the field similar and new genetic material should be introduced and as in vitro clones in slow-growth storage (Ellis et for breeding Nordic varieties (Selga et al., 2022). al., 2018). About 4.4% of these accessions were found In Estonia (EST019), for validation of varieties and to have mismatches, which is comparable with genetic identification of the origin of the material, more than mismatches found in other stock centers (Anastasio et 450 potato varieties and landraces of the Estonian al., 2011). Furthermore, around 25% of the cultivated Crop Research institute were fingerprinted using collection was genotyped with DarTseq and about 8 SSR markers and revealed unique accessions and 2,000 accessions of cultivated and wild species were duplicated varieties (Ivanova-Pozdejeva et al., 2021). genotyped with GBS. It is interesting to note that use The Latvian (LAV006) potato collection (83 accessions) of the data from the SolCAP 12k array on its own can and some additional varieties were genotyped using be used to predict the species based on Hawkes tax- Diversity Array Technology (DArT) makers resulting onomy with a high degree of accuracy. in 1,482 polymorphic loci. Overall, the material was grouped in breeding lines, Latvian, Western European North America . Many comprehensive genotyping and Eastern varieties and showed that genetic diver- studies have been carried out in the USA004 collection sity has increased in the modern varieties compared to on different topics. Recently, heterozygosity levels of varieties released prior to 1970 (Rungis et al., 2017). three diploid wild species, S. boliviense, S. amesii, and S. microdontum, and the diploid cultivated species To develop core collections and for marker-assisted S. phureja, were studied (Bamberg et al., 2021) and a selection about 2,000 accessions of the FRA010 collec- core set of 38 S. demissum accessions was established tion were fingerprinted. For further genotyping and based on 1,403 AFLP markers (Del Rio and Bamberg, genome-wide association (GWAS) studies, Cleaved 2020). In Canada, about 90 current and heirloom Amplified Polymorphic Sequence (CAPS) markers and Canadian garden potato varieties were genotyped the SolCAP 8K array were used. The Commonwealth with SSR markers to complement information from Potato Collection (GBR251) has been partly geno- the Food Inspection Agency reference SSR profile typed and used in numerous taxonomic (Hawkes, collection for potato varieties. Overall, the SSR profiles 1994; Spooner et al., 2005), breeding (Bradshaw and of 68 varieties were unique. Although some morpho- Ramsay, 2005) and screening studies including eval- logical differences appeared between heirloom vari- uation of various resistances and tolerances against eties, the genetic profiles clustered together (Marie- biotic and abiotic stress, e.g. Potato Virus Y (Torrance JoséCôté et al., 2018). et al., 2020). The collection of NLD037 is similarly used and in particular accessions of S. acaule and South America . Native potato germplasm has been S. demissum were genotyped. The results have been genotyped in several studies. For example, by used to elucidate changes during ex situ and in situ using SSR markers or the SolCAP array, 98 Argen- conservation (Cadima Fuentes et al., 2017). In Russia tinian potato landraces from ARG1347 (Sucar et al., (RUS001), 237 accessions of cultivated potato species, 2022), 809 accessions from the ‘Andigenum group’ 155 accessions of closely related wild potato of the (Berdugo-Cely et al., 2017) and 144 breeding lines VIR collections (Gavrilenko et al., 2010; Gavrilenko et from COL017 (Berdugo-Cely et al., 2021) and 152 al., 2013) and 180 varieties were genotyped with SSR Ecuadorian (ECU023) landraces were genotyped markers (Antonova et al., 2016; Antonova et al., 2020). (Monteros-Altamirano et al., 2017). To evaluate the In Germany (DEU159), the entire clonal collection was Chilean landrace collection of S. tuberosum ‘group genotyped using SSR markers and ESP016 used finger- Chilotanum’, 589 accessions from CHL071 and the printing of local potato varieties from Tenerife Island, Agricultural and Livestock Service of Chile (SAG) 104 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO were genotyped with SSR markers. It was found that Material Transfer Agreements (SMTA) are required to CHL071 maintained accessions not previously listed be used for the transfer of all material under the MLS. in SAG and more than 320 landraces were charac- In accordance with all agreements, the origin of gene- terized as unique genotypes (Muñoz et al., 2016). By bank accessions including date of access, legal permits sequencing 155 genotypes from BRA020 using SolCAP and documentation of the collecting mission must be 8303 Potato Array, different subpopulations were available for the international transfer, exchange and identified. Among these were diploid genotypes from utilization of plant genetic resources (Weise et al., Phureja group, germplasm for chip processing market 2020). class and cultivars and advanced breeding clones from Europe and Embrapa, including genotypes for fresh The survey data demonstrates that most potato market class and French fry processing (Castro et al., collections belong to governmental organizations 2018). (25 collections, Figure 6.3.1) that follow the terms and conditions of the International Treaty on Plant Overall, genotyping studies have been initiated at Genetic Resources for Food and Agriculture (ITP- various scales in the different collections. However, GRFA, 21 collections, Figure 11.6.1a). The other seven systematic overviews of these studies do not exist and collections of the 32 survey participants belong to data are only partly accessible. To support breeding different types of organizations: PER001 (CIP) is an programs in the future, recent technologies, i.e. international research center and the potato collec- SolCAP, DArTs or GBS approaches, should be applied tion is held in trust under the terms of the ITPGRFA to whole collections and emerging information needs and is available with the SMTA. NLD037, LVA006, to be strategically stored in suitable easily searchable BGR001 are research institutes, whereby NLD037 is databases. also partly governmental. DEU159 is a non-university research institute, CZE027 a private organization, and 11 .6 Policies on access to collections COL017 a decentralized public entity. Most of the largest national potato collections, such as USA004 International agreements regulate the access and and DEU159, have also assigned their material to the benefit sharing (ABS) of genetic resources and have MLS. As these holders distribute most of the acces- adopted strategies for their conservation. In partic- sions (Figure 8.4.4), about 88% (10,500 accessions) ular, the ‘Convention on Biological Diversity’ (CBD) of the accessions distributed can be provided with an entered into force in 1993 and in 2014 its supple- SMTA (Figure 11.6.1). Some Latin American (ARG1347, ment agreement the “The Nagoya Protocol on Access CHL028, COL017, GTM001), Asian (CHN116, CHN122, to Genetic Resources and the Fair and Equitable IND665) and European collections (BEL023, IRL012, Sharing of Benefits Arising from Their Utilization to LVA006, ROM007, RUS001) have not yet assigned their the CBD”. In 2004, the ‘International Treaty on Plant collections to the MLS and mostly distribute the mate- Genetic Resources for Food and Agriculture (ITPGRFA) rial through institute-specific MTAs. Overall, about 8% established a multilateral system (MLS) of access and (1,000 accessions) are distributed via institute-specific benefit-sharing for contracting parties and interna- MTAs and for 4% of the material the legal basis was tional organizations. For the purposes of conservation, not stated. None of the institutions stated that they research, training and plant breeding, facilitated distribute their material under the regulations of the access to the genetic diversity of 64 crops (Annex I) has Nagoya protocol. been provided (Halewood et al., 2018) and Standard (a) (b) Total number Acc SMTA instute-specific MTA MLS Acc distributed 20 not Asia 9,655 150 5 145 assigned 16 Europe 36,444 2,500 1,500 550 450 in process Interna onal 7,467 1,900 1,900 12 PER001 La n America 7,643 280 15 260 5 8 North America 5,999 7,200 7,200 4 assigned Total 67,208 12,000 20% 4100%,500 60% 80% 1,000 0 following not following unknown 0% 20% 40% 60% 80% 100% ITPGRFA ITPGRFA Figure 11 .6 .1 . Policies for distribution and access to material of the 32 genebanks participating at the survey. a) Number of collections subject to the conditions of the International Treaty on Plant genetic Resources for Food and Agriculture (ITPGRFA) and assigned to its Multilateral System (MLS). b) Number of collections and percentage of distributed material via Standard Material Transfer Agreement (SMTA) or an institute-specific material transfer agreement (MTA). GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 105 Number of collecons In summary, the legal basis is fundamental for the use resistance genes against various pest and diseases, of genetic resources and progress in plant breeding. such as Phytophthora and Globodera. Most European Therefore, efforts must continue to ensure legal potato collections preserve and develop national land- transfer, exchange and use of potato resources for races and varieties, i.e. Bulgarian (BGR001), German future improvements. (DEU159), Czech (CZE027), Irish (IRL012), Latvian 11 .7 Type of collection and uniqueness (LVA006), Russian (RUS001), Romanian (ROM007) and Nordic (SWE054) landraces. Similarly, CHN116 and The type of collection is important for finding unique JPN183 preserve Chinese and Japanese landraces and material to be used for breeding and development. adapted lines. As most of the material is distributed at Thereby, long-term conservation is the main objec- the national level (Figure 8.4.1), the collections are an tive of most potato collections, i.e. CHN116, CZE027, important source for new allelic diversity that can be DEU159, IND665, PER001, RUS001, USA004 (Figure introgressed in breeding programs. 11.7.1.). Nine collections are considered as working collections, including FRA010, with largest number of 11 .8 Characterization and evaluation breeding lines (10,000 accessions). Four are breeding collections (CHL071, CHN122, CUB005, IRL012) and Vegetative propagation is known to be associated three are reference collections (ARG1347, GBR165, with the spread of pathogens and pests. Clonal IRL036). Reference collections play an important propagules carry and transmit viruses, bacteria, fungi role in accession identification and authentication and parasites, and healthy propagules can be easily (FAO, 2014) and are generally well studied. These infected. In the field, the older a clone is, the more include collections preserving unique Irish (IRL036) pathogens are accumulated (McKey et al., 2010). and Argentinian landraces (ARG1347) as well as the Potato production is severely affected by several so-called ‘Commonwealth potato collection’ (CPC) serious pests and diseases that can cause yield losses preserving also 19th century British landraces (GBR165). up to 100%. Some of these are particularly invasive Six collections (BEL023, ESP016, EST019, GTM001, and devastating. These are monitored and listed, for IND665, USA004) have multiple objectives and func- example by the European and Mediterranean Plant tion as breeding, working and long-term conservation Protection Organization (EPPO) that follows the collections. guidelines of the International Plant Protection Con- vention. Based on detailed documentation, the EPPO Most of the unique material is expected to be held in recommends pests be regulated as a quarantine pest South American collections, including native Chilean in national phytosanitary regulations and discrimi- landraces of the S. tuberosum ‘Chilotanum group’ nates between A1, a pest that is not yet present in (CHL028), but also Colombian (COL017) and Peruvian the EPPO region and A2, a pest which is present in the (PER001, PER860) landraces of the S. tuberosum ‘Andi- EPPO region (Table 11.8.1). genum group’ and Brazilian (BRA020) and Ecuadorian (ECU023) wild species. Some of this material carries Genebanks follow international rules and recom- Breeding, working, long-term conserva on (6) Reference collec on (3) BEL023 Belgium varie es, resistant lines ARG1347 Argen nian landraces & wild species ESP016 Spanish landraces GBR165 UK landraces, wild species EST019 Estonian landraces IRL036 Irish landraces GTM001 Local varie es, Resistant lines IND665 - Long-term conservaon (14) USA004 US landraces and wild species BRA020 Brazilian varie es and wild species Breeding collec on (4) CHN116 - COL017 Colombian landraces, resistant lines CHL071 Chilean landraces, resistant lines CZE027 Czech varie es CHN122 - DEU159 German landraces, resistant lines CUB005 - ECU023 S. phureja and wild rela ves IRL012 Irish landraces GBR251 - Working collec on (9) LVA006 Latvian varie es, adapted lines BGR001 Bulgarian varie es NLD037 South American landraces, resistant lines BRA020 Brazilian varie es and wild species PER001 Unique South American landraces CHL071 Chilean landraces, resistant lines PER860 Peruvian landraces CAN064 Old Canadian landraces, resistant lines RUS001 Russian landraces, South American landraces FRA010 Clones of wild species, resistant lines SVN019 Resistant lines JPN183 Japanese varie es, adapted lines SWE054 Nordic landraces, adapted lines PER001 Unique landraces and wild species ROM007 Romanian landraces RUS001 Russian landraces, South American landraces Figure 11 .7 .1 . Main objectives of the potato collection of the 32 genebanks participating at the survey and the importance of their collection for use and breeding. Multiple answers allowed. 106 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO mendations, and screen material for specific pests mapping are evaluated and will be a great source for and resistance genes. This information is particularly marker-assisted selection (Sood et al., 2017). Also, the relevant for the international transfer and exchange functional stacking of resistance genes using Agro- of plant genetic resource and for the selection bacterium tumefaciens-mediated transformation has of parental lines in breeding programs. The most been proven to be successful (Zhu et al., 2012; Ghis- important pests and diseases phenotyped in 32 potato lain et al., 2019). However, further use of resistance collections are listed below. genes also depends on evaluation of potato genetic resources, appropriate screening approaches and Fungal and Late blight disease the availability of data. To date, potato collections in 27 genebanks have been screened for late blight The main biotic threat to potato production is Late resistances (Figure 11.8.1.1). Among some examples, blight, caused by the oomycete Phytophthora infes- Bachmann-Pfabe et al. (2019) examined the wild tans. It causes light to dark brown spots on leaves, potato collection of DEU159 and found 68 highly stems and tubers and diminishes tuber quality. Now- resistant and 311 partially resistant accessions among adays, effective pest management includes a combi- 1,055 accessions of S. acaule, S. fendleri, S. megistac- nation of: (1) monitoring of Phytophthora infestans rolobum, S. polytrichon, S. jamesii, Solanum trifidum population, (2) monitoring environment and weather Correll, and Solanum tarnii Hawkes & Hjert. New conditions, (3) molecular diagnostics kits and (4) blight resistant plants were also discovered in the wild smart-phone-based systems to support decisions on potato collection of USA004; in Solanum albornozii fungicide treatments (Adolf et al., 2020). Although Correll, Solanum agrimonifolium Rydb., S. chomatoph- there have been some resistance genes identified and ilum, S. ehrenbergii, S. hypacrarthrum, Solanum introgressed from S. berthaultii, S. bulbocastanum, iopetalum (Bitter) Hawkes, Solanum palustre Schltdl., S. demissum, S. microdontum, S. stoloniferum, S. ven- S. piurae, S. morelliforme, S. neocardenasii, S. trifidum, turi and S. chacoense and markers are available, some and Solanum stipuloideum Rusby (Karki et al., 2021). races of the pathogen have overcome the resistance Finally, in a screening of 79 accessions from 39 wild over time. To prevent rapid evolution of the oomycete potato species and seven species of landraces (using races, strategies to combine different resistance genes the taxonomy of Hawkes 1990), novel late blight resis- involving different mechanisms seem to be promising. tance was found in S. albornozii, Solanum andreanum Currently, novel resistance genes detected via QTL Baker, Solanum lesteri Hawkes & Hjert, Solanum lon- Table 11 .8 .1 . List of potato pests recommended for regulation as quarantine pest (EPPO, 2021). Category Common name Latin/Full name Category Fungus Potato wart Synchytrium endobioticum A2/82 SYNCEN Viruses and virus- APLV, Tymovirus Andean potato latent virus A1/244 APLV00 like organism APMMV, Mycovirus Andean potato mild mosaic virus A1/384 APMMV0 APMoV, Comovirus Andean potato mottle virus A1/245 APMOV0 Nepovirus Potato black ringspot virus A1/246 PBRSV0 PSTVd, Pospiviroid Potato spindle tuber viroid A2/97 PSTVD0 PVT Potato virus T A1/247 PVT000 PYDV, Crinivirus Potato yellow dwarf virus nucleorhabdovirus A1/29 PYDV00 PYVV Potato yellow vein virus A1/30 PYVV00 PYV Potato yellowing virus A1/220 PYV000 Bacteria & phytoplasm Potato purple top wilt Candidatus phytoplasma americanum A1/128 PHYPAE Bacterial wilt Ralstonia solanacearum A2/58 RALSSL Potato ring rot Clavibacter sepedonicus A2/51 CORBSE Insects Guatemalan potato tuber worm Tecia solanivora A2/310 TECASO Andean potato weevil Premnotrypes latithorax A1/143 PREMLA Andean potato weevil Premnotrypes suturicallus A1/143 PREMSU Andean potato weevil Premnotrypes vorax A1/143 PREMVO Colorado potato beetle Leptinotarsa decemlineata A2/113 LPTNDE Nematodes Potato cyst nematode Globodera rostochiensis A2/125 HETDRO Potato cyst nematode Globodera pallida A2/124 HETDPA GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 107 giconicum Bitter, S. morelliforme, Solanum stenophyl- ation, necrosis, wilt and a yield loss up to 50%. The lidium Bitter, Solanum mochiquense Ochoa, Solanum fungus can survive in the soil for more than 10 years cajamarquense Ochoa, and Solanum huancabambense (Jing et al., 2018). However, due to lower importance Ochoa (Perez et al., 2022). compared to the other diseases, resistances to this pathogen have only been assessed by PER001 and The fungal disease Early blight is caused by Alternaria BRA020 (Figure 11.8.1.1). solani, which infects leaves and causes dark brown to black spots with concentric rings, leading to consid- Fusarium dry rot disease is caused by more than 13 erable yield losses. The disease can be controlled by Fusarium species and results in 25–60% tuber losses a combination of elimination of soil-born inoculum in storage (Tiwari et al., 2020; Tiwari et al., 2021b). from the field, using tolerant varieties, and pesticides. Infected tubers have reduced dry matter, shrivelled However, loss of sensitivity towards specific pesticides, flesh and necroses which mummify at the final stage. i.e. succinate dehydrogenase inhibitor (SDHI) and Pest control is largely through crop rotation, appro- Quinone outside inhibitor (QoI), has been reported priate harvest and storage conditions, post-harvest in many countries. Therefore, the importance of the fungicide application, however these are reported to disease will increase in the future (Adolf et al., 2020). become less effective. None of the potato varieties are So far, only PER001 and CUB005 have had the oppor- resistant to the full range of Fusarium species, how- tunity to screen their collection fully or partially for ever resistant varieties may be an option when the this disease (Figure 11.8.1.1). Screening 217 cultivated strain is known (Bojanowski et al., 2013). In national potato accessions of the USDA ARS-Beltsville breeding and international genebanks, only four collections program revealed 28 resistant and 62 moderately have been fully or partly investigated (Figure 11.8.1.1), resistant varieties (Xue et al., 2019), which could be thus resistant resources may still be hidden. useful in future breeding programs. Interestingly, Wolters et al. (2021) identified both quantitative Virus diseases and qualitative resistance against this disease. The cross between S. berthaultii and a susceptible diploid An overview of virus diseases and the Potato Spindle S. tuberosum showed that resistence was inherited Tuber Viroid (PSTVd) is provided by Kreuze et al. quantitatively, whereas the cross between S. commer- (2020). The expansion of potato production to warmer sonii subsp. malmeanum with diploid S. tuberosum climates, such as the tropics, and continuous cultiva- revealed that resistance was inherited qualitatively. tion throughout the year, are often associated with an increase in virus vectors, and hence an increase in Potato wart is caused by the soil-born fungus Synch- potato virus diseases. Overall, more than 50 different ytrium endobioticum, which causes cauliflower-like viruses, including PSTVd, are known to infect potato galls that can grow in all meristematic tissues, except (Kreuze et al., 2020). The most common viruses in the roots. The fungus produces mobile zoospores potato are the potato virus Y (PVY), PVX, PVS, PVA, that can survive more than 40 years without a host. PVM, potato leaf roll virus (PLRV) and apical leaf curl Due to the serious losses in potato production and virus (PALCV) (Sood et al., 2017). Single infections with the long survival period, it has been listed on the PVM and PVS usually cause only minor tuber losses. In EPPO A2 quarantine list (Table 11.8.1). Based on a contrast, PVY and PLRV are the most damaging and GWAS approach, Prodhomme et al. (2020) identified widespread viruses and causes significant losses alone SNP markers significantly associated with patho- or in combination with other viruses. A combination type 1 resistance at the Sen1 locus. As the locus only of PVY, PVX and PVA can reduce potato yield by up partly explains the resistance observed, the authors assumed that new and rare haplotypes were intro- 30 duced by recombination and introgression breeding. Fungal diseases and late blight Currently, the only strategy to control the disease is 25 strict quarantine and phytosanitary measures and 20 cultivation of resistant varieties (Adolf et al., 2020). Overall, eight (ARG1347, CAN064, DEU159, GBR165, 15 NLD037, PER001, SWE054, USA004) out of 32 survey 10 participants had the possibility of screening the collec- tion fully or partly for potato wart resistances (Figure 5 11.8.1.1). 0 Late Early Potato Vercillium Fusarium Verticillium dahlia is the most common pathogen of blight blight wart wilt dry rot Verticillium wilt, a major threat for potato production, Figure 11 .8 .1 .1. The number of collections partially or fully especially in cooler climates. After infection, it impairs screened for resistances to selected fungal diseases and the oomycete late blight. Responses are provided from 32 the plant’s water uptake, leading to leaf discolor- participating genebanks. 108 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Number of collecons fully/ partly screened to 80%. In addition, some recombinant strains of in storage. The bacteria are transmitted via soil or PVY, PLRV and the PSTVd compromise potato quality through clonal material, though the role of insects is (Kreuze et al., 2020). PSTVd causes smaller leaves, not fully understood at present. The development of spindle-shaped and/or multiple small tubers, and the disease is highly dependent on the environment, reduces yield up to 64%. Although the occurrence of and the use of micropropagated Pectobacteria and PSTVd in potato has been reduced globally and largely Dickeya-free plantlets and the application of hygiene eradicated in Europe and North America, it infects standards are essential (Charkowski et al., 2020). Due different hosts of the Solanaceae family. Currently, the to the importance of other diseases, only GBR165 was most prevalent PSTVd strains in tomato can severely able to evaluate its collection for resistance plants to affect tomato fruit and potato tuber production and date (Figure 11.8.3.1). represent a threat to both markets (Mackie et al., 2019). So far, most viruses can be controlled via: (1) Clavibacter sepedonicus causes potato ring rot, also clean handling systems including virus testing, the uti- termed bacterial ring rot (BRR), a quarantine disease lization of disease-free material and sanitizing tools; that occurs in cooler climates and was first discov- (2) agronomic tools to prevent transmission through ered in Germany in 1905. So far, only Irish collections virus vectors or to eliminate virus infected plants at (IRL036) have been evaluated for resistant genes an early stage of cultivation (Polder et al., 2019); and (Figure 11.8.3.1). The bacteria is spread between (3) host plant resistances. Therefore, 15 collections infected tubers and causes tuber necrosis around a have already been evaluated for different resistant vascular ring and further wilting and leaf distortion. accessions to PVY and PVY, to PLRV (CUB005, PER001, However, due to zero tolerance policies, outbreaks are SWE054), PSTVd (IRL036) and PVS (PER001) (Figure rare and losses are limited to the loss of batch certifi- 11.8.2.1). Another genebank, the Chilota potato cation and restrictions in cropping (Charkowski et al., genebank, studied the PVY resistance genes Ryadg and 2020). Ryst and identified 99 and 17, respectively, out of 271 accessions that possess resistance genes (López et al., 2015). Some of these resistance genes have already been introduced by breeding programs. Further 30 Virus diseases resistance genes to PVA, PVV, PVS and PVM and to 25 control PVY were also mapped. However, due to the 20 complex genetics of potato, successful integration of resistances in combination with maintenance of tuber 15 quality is challenging and may require the availability 10 of acceptable additional tools in future (Kreuze et al., 2020). 5 0 Bacterial diseases PVY PLRV PSTVd*¹ APLV PMTV PVX APMV TRV*³ Charkowski et al. (2020) studied in detail potato PVS*² diseases caused by bacteria and the results are briefly Figure 11 .8 .2 .1. Number of collections partially/fully screened for resistances to Potato virus X (PVX) and Y (PVY), potato leaf summarized here. Bacteria cause severe damage to role virus (PLRV), potato spindle tuber viroid (PSTVd), Andean tubers and threaten potato production in warmer and potato latent virus (APLV), Andean potato mild mosaic virus cooler climates depending on the genus. Bacterial wilt (APMV), tobacco rattle virus (TRV). Responses are provided from 32 participating genebanks. *1 screening at IRL036, and black leg are the most important diseases, fol- *2 screening at PER001, *3 screening at SWE054. lowed by potato ring rot and common scab. Bacterial 30 wilt and brown rot are caused by the bacteria strain Bacterial diseases Ralstonia solanacearum, especially the Phylotype IIB 25 strain. It causes wilting of the leave,s and cut tubers 20 and stems show a creamy, liquid exudate. Losses in potato production are estimated at USD 1 billion 15 per year. Therefore, the organism has A2 quaran- 10 tine status in some countries. So far, no new variety has shown resistance to the bacterium (Charkowski 5 et al., 2020) although several collections (IRL036, 0 IND665,PER001) have been screened for resistance Bacteria Potato Common Blackleg genes (Figure 11.8.3.1). wilt ring rot scab The genera Pectobacteria and Dickeya cause the Figure 11 .8 .3 .1. Number of collections partially/fully screened for resistances to important bacterial diseases. Responses are symptoms of the black leg disease and tuber soft rot provided from 32 participating genebanks. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 109 Number of collecons fully/ Number of collecons fully/ partly screened partly screened The bacterial disease most frequently assessed and becomes bitter and they are not suitable for human investigated in 11 potato collections is common scab consumption. (Figure 11.8.3.1). It is one of the important potato dis- eases globally and is caused by Streptomyces species, About 14 species, most of which belong to Premno- with Streptomyces scabiei, Streptomyces acidiscabiei trypes, are considered as Andean potato weevils, with and Streptomyces turgidiscabiei being most common. Premnotrypes vorax, Premnotrypes latithorax and The bacteria infect all underground parts including Premnotrypes suturicallus being particular damaging. stems, roots, stolons and tubers, and cause necrosis These species are highly adapted to Andean climate and total loss. Quality and cropping regulations limit and are restricted to the mountainous regions from the spread. Overall, the introduction of resistance Argentina to Venezuela and resistant genes were and increased tolerance in cultivated potato would screened in the PER001 collection (Figure 11.8.4.1). be the most effective control for the bacterial dis- The adult stages feed on leaves, even up to the central ease. However, strict certification of clean material, vein. The larvae seriously damage the crop by pene- cropping regulations and sanitization of tools are the trating tubers and causing losses of between 16–45%. only approaches currently used to combat the disease, Crop rotation, early harvest, plastic barriers around which is a major challenge, in particular for devel- plantings, and removal of crop residues are the best oping countries (Charkowski et al., 2020). ways to control the weevil (Kroschel et al., 2020). Insects and nematodes In the temperate zones, the Colorado potato beetle (Leptinotarsa decemlineata (Say)) is a major pest Insect pests are commonly associated with potato pro- whose infestation can lead to a complete loss of duction and most have evolved in the center of origin potato yield. The beetle is native to Mexico and has of the crop. Kroschel et al. (2020) gave a comprehen- spread globally once at the beginning of the 20th sive overview of different insects and pointed out century. Larvae and adults are leaf feeders and com- that seven main species (potato tuber moth, Andean pletely defoliate plants. The beetles can be controlled potato tuber moth, Guatemalan potato tuber moth, at the cultural, biological and chemical level (Kroschel Andean potato weevils, pea leaf miner fly, potato et al., 2020). Evaluation to screen for resistant and psyllid, bud midge) are most relevant in tropical and susceptible accessions were carried out in ECU023, subtropical regions, two main species (European corn ROM007 and RUS001 (Figure 11.8.4.1). borer and Colorado potato beetle) affect potato production in temperate regions, and three species A common pest that has spread globally is the Green (aphids, whiteflies, ladybird beetles) can be considered peach aphid (Myzus persicae), which is assumed to as global pests. have originated in China. They damage potato pro- duction by sucking the plant sap and impairing plant The potato tuber moth (Phthorimaea operculella) is development or by transmitting virus diseases, i.e. native to the tropical mountains of South America PLRV or PVY (Kroschel et al., 2020). Often, a combi- but has spread widely and is a serious pest in tropical nation of plant protection approaches is considered and subtropical climates. The larvae of Phthorimaea and the search for resistant accessions is currently operculella damage leaves and stems and feed on underway at AGR1347, CUB005, GBR251 (Figure tubers, resulting in yield losses up to 70%. The Andean 11.8.4.1). potato tuber moth (APTM, Symmetrischema tango- lias) is native to Peru and Bolivia and has spread in recent decades. The larvae enter the stems through 30 small holes and damage the plants by feeding until Pest insects and nematodes they wilt and collapse. Losses can be up to 30% in the 25 field but increase when other tubers are re-infested 20 in storage (Kroschel et al., 2020). Guatemalan potato tuber moth (GPTM, Tecia solanivora) originates from 15 Guatemala and has been considered a major threat 10 to southern Europe since 2000. So far, the evaluation 5 of resistant plants could only be carried out in the collections of PER001, RUS001 and COL017 (Figure 0 11.8.4.1). However, the larvae feed exclusively on Guatemala Andean Colorado Aphids Nematodes tubers and leave a visible hole when they leave. An potato tuber potato potato moth weevil beetle infestation with GPTM can result in the complete loss Figure 11 .8 .4 .1. Number of collections partially/fully screened of the harvest. In general, when tubers are infested for resistances to important pest insects and nematodes. by any of the larvae of the different moths, their taste Responses are provided from 32 participating genebanks. 110 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Number of collecons fully/ partly screened The potato cyst nematodes Globodera rostochiensis amino acids accumulate, ascorbate peroxidase levels and Globodera pallida reproduce rapidly, are difficult increase and transcripts associated with photosystem to eradicate as cysts remain viable for about 20 years, II light harvesting complex decrease (Demirel et al., causing severe yield loses after hatching (López-Lima 2020), among other changes. Varieties with larger root et al., 2020). Therefore, they are quarantine pests systems have more and longer stolons, more plantlets and the identification of resistance genes is of major and tend to be more stress tolerant as the canopy interest. Many of those genes encode for immune closes earlier, reducing evaporation from the soil (Wis- receptors that include a leucine-rich-repeat domain hart et al., 2014). During tuber initiation (BBCH 50) (NB-LRR) that have been analyzed using genetic and tuberization (BBCH 70) (Figure 4.2.1), drought has mapping (Bakker et al., 2011). Furthermore, out of the greatest impact and leads to significant changes in 32 survey participants, 16 collections have partially/ tuber yield and shape, i.e. dumbbell-shaped, knobbly, fully screened their collections for resistant acces- pointy tubers (George et al., 2017). sions (Figure 11.8.4.1). When the juvenile nematodes hatch in the presence of root exudates, they invade Low temperatures, in particular below -3°C, damage roots of the host and start feeding causing symptoms the foliage in the early and late season and limit the of nutrient deficiency including yellow leaves. The vegetative period and yield potential. High tem- juvenile stages form a large syncytium and develop peratures, above 30°C, affect tuber quality and yield into adult females and males. After about 6 weeks, (Waterer et al., 2010). High temperatures modulate the adult males leave the root to fertilize the female carbon transport to sink organs, facilitate sucrose bodies that are still attached to the root. The fertilized accumulation in the phloem, which reduces sucrose females form a cyst with the next generation of eggs transfer to the sink and impairs starch syntheses. In waiting for optimum conditions to hatch (Price et al., combination with the accumulation of amino acids, 2021). In DEU159, out of 749 accessions tested, 78 Maillard reactions are promoted, producing color and accessions of S. brevicaule, S. demissum and S. micro- flavor changes and acrylamide accumulation during dontum wild species showed resistance to Globodera frying. Furthermore, among other effects, the expres- pallida (Bachmann-Pfabe et al., 2019). sion of genes related to anthocyanin and steroidal gly- coalkaloid pathways is modulated, altering the benefi- The description of some of the pests and diseases and cial impact on human health. Besides brown spots and the available protection instruments has shown that necrosis, high temperatures affect tuber development, none of them can be easily defeated by chemical, bio- causing irregular shapes, cracks, secondary tuber for- logical protection, sanitation or cultivation approaches mation and reduced tuber dormancy that can result in on their own. To minimize the use of pesticide and early sprouting (George et al., 2017). avoid the loss of their efficacy and the loss of plant- pathogen resistance mechanisms, a combination of Extensive use of fertilizers, chemicals and irrigation different protection approaches has been promoted have considerable impacts on soil salinity. Increased by most researchers (Kroschel et al., 2020). The salinity induces detrimental changes in the root so-called Integrated Pest Management involves a com- system, with decrease in number, diameter and length bination of: (1) best agricultural practice, including of roots (Chourasia et al., 2021) affecting photosyn- the use of healthy propagules, crop rotation, biolog- thesis, protein metabolism, respiration, protection ical control, and sanitizing tools; (2) the application of mechanisms and nutrient balances, among others. The monitoring, modelling and prediction tools to prevent impairment of metabolism leads to lower tuber yield, pest population growth; (3) the control rather than browning and cracking of the tuber surface (George the complete elimination of pests; and (4) continuous et al., 2017). evaluation of the results and adjustments. Most genebanks have started to screen for abiotic Abiotic stresses stresses (Figure 11.8.5.1). Of the 32 survey participants, 11 potato collections (ARG1347, CHL023, CHN116, Climate change and growth under sub-optimal condi- CHN122, CUB005, ESP016, GBR251, GTM001, PER001, tions affect potato development. Depending on the SVN019, USA004) were fully or partially screened for type of stress, and its intensity, duration and occur- drought. Six collections were able to evaluate their rence during the vegetation period, potato yield and collections for high and low temperatures and salinity. quality can be severely changed. Potato in particular In particular, CAN064, CUB005, GBR251, IND665, is sensitive to drought due to its flat root system and PER001, and USA004 were interested in the response inefficient recovery of photosynthetic systems (George to high temperatures. CHL028, CHN116, CHN122, et al., 2017). With reduced water availability, lateral GTM001, PER001, and USA004 had the chance to roots proliferate and root elongation and root-hair evaluate parts of their collection for frost resistance or production are significantly reduced, affecting the response to low temperatures and ARG1347, CHL028, root-soil contact (Wishart et al., 2014). In addition, CHN122, NLD037, and USA001 for salinity. Other abi- GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 111 otic stresses and traits investigated by some collections the potato yield is predicted to decline by 26% by were nitrogen deficiency (CAN064, DEU159), mechan- the end of the century. Significant impacts on potato ical damage (CZE027, PER001), waterlogging (CHN116, yield and quality are forecast at high latitudes, such DEU159), phosphorus deficiency (DEU159), long-/short as Eastern Europe and North America, the lowlands day adaptation (PER001), shade adaptation (PER001). of sub-Saharan Africa, though less in mid-latitude and tropical highlands (Raymundo et al., 2018). 11 .9 Challenges and Priorities 30 Potato breeding programs are challenged to introduce Abio c stresses 25 new quality traits, and pest and diseases resistances, in combination with increased tuber yield, which is diffi- 20 cult due to the complex genetic nature of the crop. As 15 a result, yield has hardly improved in the last century (Douches et al., 1996). Climate change is leading to 10 more frequent occurrence of frost, heat waves and 5 drought, including effects on increased soil salinity and changes in the distribution and incidence of pest 0 Drought Heat Cold Salinity and diseases (Dahal et al., 2019). According to the pre- Figure 11 .8 .5 .1. Number of collections partially/fully dictions of Raymundo et al. (2018), potato production screened for abiotic stresses. Responses are provided from 32 will be only moderately affected until 2055. However, participating genebanks. Genome informa�on Genome sequencing, genotyping & genome-wide associa�on mapping Improved genetic informa�on about resistances to bio�c and abio�c stresses, crossing barriers, self-incompa�bilites, deleterious muta�ons, dysfunc�onal & beneficial alleles Potato Gene�c Resources Standards for genotyping Genome and marker sequencing Iden�fica�on of unique accessions & duplicates Taxonomic determina�on Agronomical characteriza�on Robust screening tools Data availability on adequat pla�ormes Robust data analysis tools Popula�on Iden�fica�on of superior genotypes development Legal availability of viable material Conven�onal Parental selec�on Selec�on breeding Selec�on based on 10 - 30 years Trait heritability, variance, co-variance Female development Systema�c ma�ng, progeny tes�ng Male development Es�mated parental value Es�mated breeding value Recombina�on Marker-assissted selec�on CRISPR/ Hybrid Cas breeding 5 - 10 years Selec�on F1 Hybrid seed Test crossing F1 True potato seed Virus-free plants/tubers Figure 11 .9 .1 . The use of potato genetic resources in potato breeding programs and information needed to increase tuber yield and improve quality. 112 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Number of collecons fully/ partly screened N₂ deficiency Mechanical damage Waterlogging M. Nagel (2022) To improve the productivity of potato, genomic infor- development of databases (Genesys, EURISCO) to mation, characterization and evaluation and plant provide characterization, evaluation and geno- breeding have to be further developed, and will affect typing information ex situ conservation (Figure 11.9.1). In detail, specific 4 . Broadening genetic diversity in cultivated potato requirements include: by a) introduction of stress resistant genotypes of 1 . Improve genome information of cultivated and landraces or wild species, or b) improvement of wild potato species, including improved assembly diploid potato germplasm before introgression into algorithms, increased read lengths, and de novo tetraploid material sequences of additional haplotypes to elucidate a 5 . Application of advanced breeding tools such as full catalogue of genes that provide the genetic a) genomic selection using estimated breeding basis for resistances, deleterious mutations, dys- value and marker-assisted selection, and b) hybrid functional and beneficial alleles breeding systems 2 . Improved genotyping and phenotyping of germ- 6 . Enhanced interdisciplinary and international col- plasm collections using robust and standardized laboration to develop Integrated Pest Management approaches and data analyses tools to identify resis- systems and to improve tuber yield and quality tances, beneficial traits and superior individuals (breeders, geneticists, conservation biologists, phy- 3 . Increased accessibility of the germplasm and topathologists, data managers, agronomists) associated information, including the continuous GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 113 12 RECOMMENDED PRIORITIES The 32 institutions participating in the survey con- to coordinate activities and to ensure adequate data serve more than 69,000 accessions, representing more analysis, the international community needs to agree than 80% of the global potato collections. The Latin on 2) standards for genotyping, and the definition of American countries, plus CIP (PER001) and DEU159, duplicates and unique accessions, and 3) to establish GBR251, NLD037, RUS001, and USA004 maintain large user-friendly analysis platforms, 4) ensure effective collections of wild species and landraces, whereas linkage between passport and genomic data of acces- most other European and Asian collections maintain sions, and 5) support further genome research and extensive collections of heirloom varieties, varieties broaden genetic information on resistances, delete- and breeding lines. Thus, based on the data provided rious mutations, dysfunctional and beneficial alleles. by the survey participants, a comprehensive overview of the conservation status of potato genetic resources Action Point 2: Harmonization of can be obtained, and strategic priorities can be recom- potato taxonomy mended. Correct taxonomic identification is a foundation for Action Point 1: Comprehensive geno- the conservation of genetic diversity. Currently, potato typing of ex situ and in situ collections . collections are classified according to three different systems, with VIR (RUS001) following Bukasov (1978), Genotyping is needed in various fields of conservation yet most genebanks apply Hawkes (1990) due to the activities, in particular for taxonomic classification, col- precise characterization of species and detailed and lection management (including identification of dupli- comprehensive morphological descriptions. Although cates and unique accessions), gap analysis and use of GRIN does not obligate genebanks to use the more collections. Therefore, 1) comprehensive genotyping recent classification system of Spooner et al. (2014), of all accessions maintained ex situ and of material most genebanks using GRIN follow that revision of the preserved in situ and on farm is required. However, 228 wild potato species, seven cultivated species and 114 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Potato flower. Photo: Michael Major/Crop Trust 19 taxonomic series recognized by Hawkes (1990). On ability of healthy and good quality planting material basis of molecular and morphological data, Spooner for further propagation and distribution of local et al. (2014) combined the Hawkes (1990) taxa into varieties among the members of local communities. 107 wild and four cultivated potato species. This poses In addition, 4) collaborations between landowners some challenges for use of the collections and the and local universities should be promoted to raise the identification of gaps. Therefore, the international awareness and improve the assessment of the avail- community needs to agree on 1) a universal and able diversity of wild relatives and native landraces. predictive taxonomy and/or 2) the classification system Universities may run courses, research projects and used needs to be stated in documentation systems improve the technical skills of farmers and indigenous and respective synonyms need to be transparent and families to support the identification of unique mate- be provided in public databases (EURISCO, Genesys, rial and further in situ conservation. GRIN). Furthermore, if Spooner et al. (2014) will be more widely applied in future 3) a suitable system for Action Point 5: Collecting missions and subdividing large groups of species is required because linkage between in situ/on farm and ex gaps can be more easily identified in smaller groups. situ conservation Also, 4) names of sub-groups should be associated with traits and 5) intermediate forms could be given Effective complementary conservation strategies an appropriate name indicating their origin. are needed in the potato center of origin. Activities need to be intensified 1) to repatriate native potato Action Point 3: Documentation and genetic resources, and the diversity they contain, to monitoring of in situ populations and local communities as needed and 2) to support on traditional landraces maintained on farm management by providing healthy disease-free farm in American countries propagules. In the local communities, 3) the local on farm and in situ diversity needs to be assessed and To successfully conserve wild potato species and tradi- conserved ex situ. Due to habitat changes or intro- tional landraces in situ and on farm, more information duction of invasive species 4) missions to collect wild is required on natural populations and traditional species are urgently required and must be supported landraces grown in different places. Therefore, 1) by local policy makers, well-experienced collectors and inventories of crop wild relatives, including IUCN Red gap analysis. 5) Missions to re-collect material may List status, ecology, distribution patterns, taxonomy, be considered because mutations, natural selection, traditional knowledge and use should be conducted, genetic drift and gene flow have a significant impact 2) changes in diversity in wild populations and of on local genetic diversity. 6) The international commu- potato landraces should be monitored. A global early nity must support collecting missions through inter- warning and monitoring system such as the in situ national collaboration, which is highly appreciated by conservation monitoring system for root and tuber the Latin American genebanks. 7) The impact of the crops and bananas currently being developed by the repatriation work and collecting missions needs to be Alliance of Bioversity and CIAT could provide such evaluated to determine and improve their success. a platform for monitoring potato diversity globally. Furthermore, the international community needs to Action Point 6: Capacity building to agree on 3) standard procedures to measure conser- maintain high quality ex situ collec- vation status and robustly monitor the dynamics of tions, in particular in Latin American landrace pools in selected hotspots, especially in the countries Andes and on the Chiloé islands. Long-term ex situ conservation of potato genetic Action Point 4: Capacity building for in resources can only be successful if appropriate storage situ conservation and improved stra- conditions and best conservation practices are applied. tegic concepts for on farm conservation In particular, in Latin American countries, genebanks need facilities for cold storage, cryopreservation and Indigenous families still passionately maintain potato tissue culture to preserve their material according to diversity for the benefit of all humanity, and yet they internationally agreed Genebank Standards. In par- live in poverty. Therefore, 1) incentives for in situ con- ticular, to 1) store field-grown tubers under optimum servation and on farm management of native potato conditions, 2) back up field collections in vitro or in varieties and crop wild relatives need to be provided cryo, 3) improve plant health and eliminate viruses to compensate for the low economic profitability of and diseases, 4) preserve seeds and 5) to support this local biodiversity. Further, support is required safety back ups at different sites. In addition, 6) full 2) for the development of marketing strategies to documentation of all procedures is required to ensure achieve higher prices for local varieties, and 3) to an appropriate guidance for technical staff, and thus improve the local seed system and enhance the avail- high conservation quality. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 115 Potato flower. Photo: Michael Major/Crop Trust Action Point 7: Cryopreservation is into GRIN, EURISCO or Genesys. The IPD should be needed to ensure long-term survival of embedded in data management systems that transfer potato genetic resources their data to the public domain. Public availability of data is a prerequisite for identifying unique accessions Clonal potato genetic resources, and possibly true and duplicates, analyzing gaps, assessing the threat potato seeds, can be securely conserved for the long- potential to wild populations and traditional land- term at minimal costs by cryopreservation. Therefore, races, and the use of in potato genetic resources. the international community needs to 1) support the Global Plant Cryopreservation Initiative and cryo- Action Point 9: Accessibility of collec- preserve all unique potato accessions, 2) agree on tions for breeding and use standards for ‘best practice’ and storage, and 3) study fundamental processes and optimum preservation Potato breeding suffers from stagnating yields and conditions to ensure high shoot-tip and seed survival faces challenges related to climate change. There- after cryopreservation. fore, to improve the third most consumed crop, it is commonly agreed that there is a need to broaden the Action Point 8: Further digitalization, genetic diversity in cultivated potato, including the better linkage and visibility of publicly introduction of resistant landraces and wild species. available data for ex situ and in situ Therefore, there is a need for 1) well-documented conservation management core collections and 2) easy access to genebank data, genomic information, characterization and evalu- Data management is fundamental for the success and ation data, which includes further development of the quality of the genebank management and in situ databases (GRIN, EURISCO, Genesys) and 3) inden- conservation. The electronic availability of protocols, tification of the specific needs of the international procedures, workflows, specific know-how, as well as community of users. 4) FAIR principles (findable, continuous documentation, secure data storage and accessible, interoperable, reusable) may be introduced registration of in situ inventory linked to traditional as standard for all phenotypic data (descriptors) and knowledge, can ensure the high quality of available 5) healthy and virus-free plant material 6) must be material, and thus long-term conservation of potato available in required quantities and 7) via the SMTA. genetic resources. To date, no global data manage- 8) Further research to overcome self-incompatibilities ment system is in place for in situ conservation, and and sterility barriers, and on molecular and hybrid thus the data are marginally if at all accessible. There- breeding tools, is essential for the future of this fore, there is an urgent need for the 1) implemen- important crop. tation of in situ and genebank information systems recording all data, including inventory, passport, Action Point 10: Networking and characterization and evaluation data, digitalization of training voucher specimen, and for 2) the improvement of the linkage between in situ, genebank and other pub- To address specific challenges related to potato in the licly available data, in particular sequencing data and future, to raise awareness of the need conservation voucher specimens. Here, the 3) integration of Digital and to efficiently manage pests and diseases, 1) inter- Object Identifiers (DOI) available to PGR collections disciplinary and international collaboration between through the GLIS DOI portal can support the linkage breeders, curators, geneticists, conservation biologists, of material across genebanks and beyond. Further- phytopathologists, data managers, and agronomists more, the accessibility of in situ and genebank mate- are required 2) to develop efficient staff training pro- rial will be improved when 4) the data are integrated grams, 3) to monitor in situ conservation status and into other platforms i.e. GRIN, EURISCO or Genesys 4) to implement global conservation planning and 5) and 5) the data available in the Intergenebank Potato Integrated Pest Management systems. Further discus- Database (IPD) that matches wild species acces- sions are needed to 6) adapt descriptors and gene- sions between eight genebanks are also integrated bank information for breeders and users. 116 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO REFERENCES Acker, J.P., Adkins, S., Alves, A., Horna, D., and Toll, Ecuador: INIAP, Estación Experimental Santa Cata- J. (2017). Feasibility study for a safety back-up lina/CIP, 21–32 cryopreservation facility. 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A survey to build a global conservation strategy for potato Background The Global Crop Diversity Trust (“The Trust”) is supporting efforts to develop strategies for the efficient and effec- tive conservation of crop diversity, particularly in ex situ collections. The Trust has commissioned an independent external consultant (Manuela Nagel) to coordinate the development of a conservation strategy for germplasm holdings of the ‘tuber bearing Solanums’, commonly known as potato. This questionnaire has been developed for the purpose of seeking the advice and input of representatives of relevant stakeholders around the world in the development of the conservation strategy. In particular, the questionnaire seeks to assess the status of the conser- vation and management of crop genetic resources of potato, both wild and cultivated, throughout the world. If you or one of your colleague’s curate a collection that includes accessions of potato, either wild or cultivated, we would kindly ask you to complete all sections of the questionnaire. If there are no ex situ collections of potato within your institute, please complete questions 74 and 75 only. The Crop Trust are keen to have your active participation in the development of the potato conservation strategy and will be pleased to keep you informed on its progress and consult with you, either during its development or at completion. If you have any questions about this questionnaire or about the proposed strategy in general, please contact. Does your institution maintain an ex situ collection of potato? Yes | No ORGANIZATION INFORMATION Name and address of organization holding/maintaining the potato collection Address | City | Postal Code | Country | Website Curator in charge of the potato collection Name | Address | City | Fax |Email Name of respondent to this questionnaire if not as above Contact details | Date of response Additional key contact person for the above germplasm collections Name | Title/Function | Email Address Please describe the organization Governmental organization | University | Private organization |NGO or charity | Other: please describe Is the institution in charge of the potato collection the legal owner of the collection? Yes | No | If no, who is the owner (including no owner identified)? Is the collection subject to the terms and conditions of the International Treaty on Plant genetic Resources for Food and Agriculture? Yes | No If yes, has the material been assigned to the Multilateral System (MLS)? Yes, already assigned | Not currently assigned to the MLS In the process of preparing for the materials to be assigned to the MLS If no, is it expected to become part of the International Treaty in the near future? If yes, indicate expected date | No GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 133 Could you summarize your use of Material Transfer Agreements? SMTA ( % of total MTA’s) | Nagoya Protocol ( % of total MTA’s) | Institute specific ( % of total MTA’s) OVERVIEW OF THE POTATO COLLECTION Main objective of the collection (long-term conservation, working collection, breeding collection, reference collec- tion) Long-term conservation | Working collection | Breeding collection | Reference collection Other (Please specify) Please indicate the number of species by type of germplasm Type of germplasm (where known) Number of species Wild potato species Potato landraces Improved potato cultivars Breeding/research materials Unknown Other, specify: Please indicate the number of accessions by type of germplasm Type of germplasm (where known) Number of accessions Wild potato species Potato landraces Improved potato cultivars Breeding/research materials Unknown Other, specify: Please indicate the proportion (%) of accessions available for distribution by type of germplasm Type of germplasm (where known) % available for distribution Wild potato species Potato landraces Improved potato cultivars Breeding/research materials Unknown Other, specify: Origin of the collection: please indicate the proportion (%) of accessions on the total amount that were Percentage % collected originally in your own country (national origin) collected originally in your own region (regional origin) introduced from a collection abroad from other origin (please define): If you were asked to describe your collection in general terms, which of the following categories would best you place your collection . Good Global coverage | Good regional coverage: which regions? | Good National / multinational coverage? which countries? | If regional or national/multinational coverage applies, please highlight what regions or coun- tries are included: Do you consider there to be any major gaps in the collection? Species coverage of the crop: Yes ( ), No ( ) | Population (sample) representation per species: Yes ( ), No ( ) | Eco- logical representation of the species: Yes ( ) , No ( ) | Other, please specify: 134 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO If yes, are there any plans to fill such gaps and if so, please provide details on the plans . Are there any specific aspects or specialist dimensions relating to your collection that you consider to be unique or that you actively promote e .g . sets of heritage cultivars, old native cultivars, host differentials or type lines)? Has your Potato collection at least partially been screened for biotic stresses? Yes | No | If yes, for which major diseases or insect pests? Has your Potato collection at least partially been screened for abiotic stresses? Yes | No | If yes, for which abiotic stresses? Has there been any genotyping or marker studies conducted on your Potato collection? Yes | No If not no, could you indicate the scale of these studies (number of accessions); Partial (no. accessions) | Focused subsets (no. accessions) | Major or near complete collection (no. accessions) If so, is this data publicly available? Yes | No | Website for the data: Please describe the main potential/importance of your collection for use and breeding CONSERVATION STATUS (GERMPLASM MANAGEMENT) Conservation facilities . Please indicate the proportion of the accessions maintained under the following conditions: Note: if accessions are maintained under more than one storage condition the total percentage may exceed 100%) Condition Percentage % Short-term storage Medium-term storage Long-term storage Other, please specify: Please describe the storage facilities (1) Facility 1 Type of facilities Temperature Relative Humidity (%) Packing material Other, please specify Please describe the storage facilities (2) Facility 2 Type of facilities Temperature Relative Humidity (%) Packing material Other, please specify Please describe the storage facilities (3) Facility 3 Type of facilities Temperature Relative Humidity (%) Packing material Other, please specify GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 135 Have you established a genebank management system or written procedures and protocols for: Acquisition (including collecting, introduction and exchange): Yes ( ), No ( ) | Regeneration Yes ( ), No ( ) | Char- acterization Yes ( ), No ( ) | Storage and maintenance : Yes ( ), No ( ) | Documentation : Yes ( ), No ( ) | Health of germplasm : Yes ( ), No ( ) | Distribution : Yes ( ), No ( ) | Safety-duplication : Yes ( ), No ( ) Other please specify In case you have procedures and protocols, are you able to provide the Global Crop Diversity Trust with this infor- mation (i .e . provide a copy)? Yes | No Please describe your quality control activities (in terms of frequency, protocols/methods and actions upon results) Germination tests Viability testing (including from in vitro storage) Health testing Other, please specify Is the collection affected by diseases that can restrict the distribution of the germplasm? Yes | No If yes or slightly, are knowledge and facilities available at your institution for eradication of these diseases? Yes | No Please indicate the proportion (%) of the collection that requires urgent regeneration (apart from the normal routine regeneration) Type of germplasm % of accessions with urgent regeneration need Wild potato species Potato landraces Improved potato cultivars Breeding/research materials Unknown Other, specify Please indicate the current and expected situations of the collection with respect to the following factors, where: 1 = high/good, 2 = adequate/moderate, 3 = not sufficient/bad, NA = not applicable Factors Current Expected situation situation in 2025 Funding for routine operations and maintenance Retention of trained staff Interest for Plant Genetic Resource Conservation by donors Genetic variability in the collection as needed by users/breeders Access to germplasm information | (passport, characterization, evaluation) Active support/feedback by users Level of use by breeders Level of use by researchers Other factors (please specify) 136 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO SAFETY DUPLICATION (defined as the storage of a duplicate/copy of an accession in another location for safety back-up in case of loss of the original accession) Are accessions safety-duplicated in another genebank? Yes | No If you answered yes to previous question, please specify (safety duplcation1): Name of institute maintaining your safety duplicates (name) Number of accessions (number ) Storage conditions | (short, medium, long term) (short, medium, long term) Nature of the storage | (e.g. black box, fully integrated in host (e.g. black box, fully integrated in host collection, etc.) collection, etc.) Add lines as necessary If there is a second site for safety duplications, please specify: Name of institute maintaining your safety duplicates (Name) Number of accessions (number ) Storage conditions | (short, medium, long term) (short, medium, long term) Nature of the storage | (e.g. black box, fully integrated in host (e.g. black box, fully integrated in host collection, etc.) collection, etc.) Add lines as necessary If there is a third site for safety duplications, please specify: Name of institute maintaining your safety duplicates (Name) Number of accessions (number ) Storage conditions | (short, medium, long term) (short, medium, long term) Nature of the storage | (e.g. black box, fully integrated in host (e.g. black box, fully integrated in host collection, etc.) collection, etc.) Add lines as necessary Is there any germplasm of other Potato collections safety-duplicated at your facilities? Yes | No If yes, please specify (1): Name of holder of original collection Number of accessions Storage conditions | (short, medium, long term) Nature of the storage | (e.g. black box, fully integrated in host collection, etc.) If accessions from other collections are safety duplicated at your genebank (2), please specify: Name of holder of original collection Number of accessions Storage conditions | (short, medium, long term) Nature of the storage | (e.g. black box, fully integrated in host collection, etc.) To what extent do you consider the potato accessions in your collection to be unique and not duplicated exten- sively elsewhere (i .e . EXCLUDING safety-duplication)? | Are there any specific aspects relating to these unique accessions that are associated with this attribution e .g . National heritage, genetic stocks or host differentials . Fully unique | Mostly unique | Partially unique | Fully duplicated elsewhere Are there any constraints to duplicating the collection elsewhere outside your country? Yes | No | If yes, please specify. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 137 INFORMATION MANAGEMENT Do you use an electronic information system for managing the collection (data related to storage, germination, distribution, etc .)? Yes | Partly | No | If yes, what software is used? Please specify the proportion (%) of the collection with data available in electronic format . Passport data % Characterization data % Evaluation data % Please specify the proportion (%) of the collection with data available in paper form . Passport data % Characterization data % Evaluation data % In case the collection is not computerized, are there plans to do so in the future? No plans | Computerization planned within 3 years | Other Is information of the collection accessible through the Internet? Yes | Partly | No | If yes, please specify web address Are data of the collection included in other databases? National Yes ( ), Partly ( ), No ( ) | Regional Yes ( ), Partly ( ), No ( ) | International Yes ( ), Partly ( ), No ( ) If yes or partly, specify the databases DISTRIBUTION AND USE OF MATERIAL What proportion (%) of the total collection is AVAILABLE for the following distributions? Nationally: % | Regionally: % | Internationally: % Please fill in the number of accessions DISTRIBUTED annually (average of last 3 years) Number of accessions distributed annually (average of last 3 years) Nationally % Regionally % Internationally % How do you expect your distributions to change over the next 3–5 years? Indicate any expected change over the next 3–5 years? Expected change for the next 35 years Nationally Increasing ( ), No change ( ), Decreasing ( ), Don’t know ( ) Regionally Increasing ( ), No change ( ), Decreasing ( ), Don’t know ( ) Internationally Increasing ( ), No change ( ), Decreasing ( ), Don’t know ( ) Regarding the amounts of seed, do you set specific conditions for distribution? Please specify Is the germplasm sufficiently available in terms of QUANTITY for distribution? Seeds: Yes ( ), Partly ( ), No( ) | Other, please specify: Yes ( ), Partly ( ), No( ) Is the germplasm sufficiently available in terms of HEALTH for distribution? Yes | Partly | No Do you have adequate procedures in place for Phytosanitary certification? Yes ( ), Partly ( ), No( x ), I don’t know ( ) | Packaging? Yes ( ), Partly ( ), No ( ), I don’t know ( ) | Shipping? Yes ( ), Partly ( ), No ( ), I don’t know ( ) | Other: Yes ( ), Partly ( ), No ( ), I don’t know ( ) | If Other please specify 138 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Do you keep records of the distribution? Yes | No Which type of the following users received germplasm from you in the past 3 years? Type of users Proportion of total distribution % Farmers and farmers’ organizations Other genebank curators Academic researchers and students Domestic users Foreign users Plant breeders - public sector Plant breeders - private sector NGOs Others, please specify: How do you inform potential users about the availability of accessions and their respective data in your collec- tion? What are the most important factors limiting the use of the material maintained in your collection? Please describe your policy regarding accessibility and distribution of Potato germplasm | (i .e . free or cost . If cost, please specify the amount) Cost of accessions: Free ( ), Cost ( ) | Cost of shipment: Free ( ), Cost ( ) | Cost of phytosanitary/growing season inspections: Free ( ), Cost ( ) Do you have any restrictions on who can receive materials? Yes | No | If yes, please specify COLLABORATION WITH OTHER GENEBANKS AND/OR BREEDERS OF THE PUBLIC OR PRIVATE SECTOR IN TERMS OF GERMPLASM MANAGEMENT? Does your genebank collaborate with other genebanks and/or breeders of the public and/or private sector on aspects of germplasm management (regeneration, characterization, preliminary evaluation), apart from safety duplication? Yes | No If YES, please provide the following information on your collaboration: (1) Name of institution Name of institution Location Type (public or private) Type of collaboration (national, regional, international) Area of collaboration (regeneration, characterization, preliminary evaluation) Starting date and frequency of collaboration (annually, once every few years, seldom) If YES, please provide the following information on your collaboration: (2) Name of institution Name of institution Location Type (public or private) Type of collaboration (national, regional, international) Area of collaboration (regeneration, characterization, preliminary evaluation) Starting date and frequency of collaboration (annually, once every few years, seldom) GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 139 If YES, please provide the following information on your collaboration: (3) Name of institution Name of institution Location Type (public or private) Type of collaboration (national, regional, international) Area of collaboration (regeneration, characterization, preliminary evaluation) Starting date and frequency of collaboration (annually, once every few years, seldom) Do you collaborate in (a) network(s) as a Potato collection holder? Yes | No If YES, please provide the following information for each of the networks: (1) Name of network National/ Regional/ Worldwide Objectives Reasons for participation If YES, please provide the following information for each of the networks: (2) Name of network National/ Regional/ Worldwide Objectives Reasons for participation If your institute does not maintain an ex situ collection of Potato, please help us by indicating to the best of your knowledge, the following Current conservation activities Institute focal person to contact for further details Plans for any ex situ conservation Any other information Please add any further comments you may have Please return the questionnaire to Glenn Bryan (Glenn .Bryan@hutton .ac .uk) as soon as possible . 140 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Annex 2 . Selected metrics for potato and cassava (as comparison) The summary in this annex was written by Dr. Felix Frey, International Consultant, Global Crop Diversity Trust. Khoury et al. (2022) compiled a comprehensive dataset countries, where cassava is only produced in 48% of as part of a project funded by the International Treaty the world’s countries. Potatoes are consumed in all on Plant Genetic Resources for Food and Agriculture, reporting countries in the world (100%), whereas the with the collaboration of the Crop Trust, led by the percentage of countries consuming cassava is 62%. International Center for Tropical Agriculture (CIAT). Although both crops are internationally traded tubers, The aim was to introduce five normalized, reproduc- potato trade is of lower importance than cassava ible indicators to serve as an evidence base when trade. Only 18 million tons of potatoes are exported, prioritizing actions on the conservation and use of which is 47% of the exported amount of cassava plant genetic resources for food and agriculture. The production (39 million tons). Exports represent 5 and indicators encompass metrics associated with the USE 15% of global production of potatoes and cassava, of a crop (Global importance), the INTERDEPENDENCE respectively. between countries with respect to genetic resources, the DEMAND among researchers for genetic resources, The crop use metrics with respect to research were the SUPPLY of germplasm by genebanks and the assessed using a manual search on Google Scholar, SECURITY of germplasm conservation. Graphs of the searching for the respective genus or species in the indicator results are publicly available on an interac- titles of publications, including patents and citations, tive website. To generate the five indicators, Khoury between the years 2009 and 2019 (Khoury et al., et al. (2022) collected a comprehensive dataset from 2022). Search hits on Google Scholar indicate the level multiple sources. We do not present those indicators of scientific interest in a crop. The Solanum genus here, but rather discuss the underlying raw data to is found in 16,500 publication titles, which is almost shed light on the aspects represented by the indicators four times as much as publication titles including the with respect to potato. cassava genus Manihot (4,220). However, it should be accounted for that the genus Solanum includes To put numbers into context, we compare potatoes other globally important crops, such as tomato and with cassava (Annex Table A2.1). Both crops are grown eggplant. Publications with titles including the species for their starchy tubers, which are important sources names of potato and cassava are more comparable. of carbohydrates and protein for human consump- The potato species names S. tuberosum, S. ajanhuiri, tion. Both originate from the Americas. Potatoes are S. juzepczukii and S. curtilobum appear in 6,160 pub- represented by the genus Solanum and the species lication titles, where Manihot esculenta is included in S. tuberosum, S. ajanhuiri, S. juzepczukii and S. curti- 3,120 publication titles. If related to the comparison of lobum. Manihot and Manihot esculenta are the genus production between both crops presented previously, and species names of cassava, respectively. potato research is slightly overrepresented when com- pared to cassava research. The metrics for “Global production,” “Food supply” and “Quantity exported globally” under the indicator Khoury et al. (2022) defined interdependence as a domain “Crop use” are annual average values drawn measure of the degree of dependence of global culti- from FAOSTAT for the years 2010–2014 (Khoury et al., vation and use of a certain crop on the primary center 2022). The percentage of countries producing and con- of diversity of the crop. Primary centers of diversity suming (being supplied with) the crop is calculated as are not represented by countries, but by 23 agroeco- the number of countries where the respective crop is logical zones (Khoury et al., 2016), as crop diversity within the top 95% of most important crops, divided does not follow national borders but rather climatic by the number of countries that report respective and agroecological boundaries. Interdependence is numbers (can be different between metrics and crops). high in crops that originate from a small area and are The global production of potatoes is estimated at 363 cultivated and used globally. For production, interde- million tons annually, which is close to 50% more than pendence is calculated by dividing a crop’s production the global cassava production (254 million tons). The outside the primary center of diversity by its global quantity of food supply by potatoes, i.e. the average production. If all production is outside the primary global consumption, is at about 94 g cap-1day-1, which center of diversity, interdependence would be 100%. is more than double (241%) of food supply by cassava For food supply, interdependence is calculated by (39 g cap-1day-1). Potato food supply is thus relatively dividing the food supply by the world average. Food high, compared to its production. Percentage of coun- supply outside can be higher than that inside the pri- tries producing potatoes is relatively high compared mary center of diversity and thus also higher than the to cassava. Potatoes are produced in 74% of reporting global mean. Therefore, interdependence with respect GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 141 to food supply can be above 100%. The primary center of 122,252 Solanum accessions, including all Solanum of diversity of potato is located in Andean South crops. 27,750 of these accessions are contributed by America. As China and India are the most important the potato species. The number of cassava accessions potato producers (FAOSTAT, 2021b), interdependence stored in global ex situ collections is 18,886 with of global production is at 98 % very high. Centers respect to the genus Manihot and 17,831 for the of diversity of cassava are located in Tropical South species Manihot esculenta. Both potatoes and cassava America as well as Central America and Mexico, while are listed in Annex I of the Plant Treaty (FAO, 2009b). the main countries producing cassava are Nigeria, At the genus level, the percentage of accessions the Democratic Republic of the Congo and Thailand available under the MLS is 32 and 35% for potatoes (FAOSTAT, 2021b). Interdependence of global pro- and cassava, respectively. At the species level, the duction of cassava is thus also relatively high, with a percentage of accessions available under the MLS is value of 89%. The interdependence of food supply 45% for potato and 34% for cassava. However, a high per capita of potatoes and cassava are also relatively percentage of accessions of both crops can be made high, with values of 100 and 94%, respectively. This is available indirectly by matching institute countries putatively due to the fact that potatoes are commonly with party status. On the species level 88 and 91% of consumed globally, and cassava is mostly consumed potato and cassava accessions, respectively, are avail- on the African and Asian continents (FAOSTAT, 2021a), able in the MLS. outside of their primary centers of diversity. Security of germplasm conservation is represented Demand for germplasm is defined by two metrics here by two metrics: safety duplication at the Svalbard (Khoury et al., 2022): (1) the number of distributions Global Seed Vault (SGSV) and the equality of global of accessions by genebanks, as an annual average distribution with respect to several crop use metrics. between 2014 and 2017, drawn from the Plant Treaty’s The numbers of accessions, by genus and species, Global Information System; (2) the number of vari- safety duplicated were taken from the SGSV website eties released during the five years between 2014 and and divided by the total number of accessions stored 2018, obtained from the International Union for the in global ex situ collections, with the result giving the Protection of New Varieties of Plants (UPOV). There is percentage of germplasm that is safety duplicated. To a relatively strong use of potato germplasm, reflected represent the equality of distribution across different by the 13,483 accessions per year distributed by gen- agroecological regions of the world (Khoury et al., ebanks. In contrast, only 1,388 cassava accessions are 2016), Khoury et al. (2022) used the reciprocal 1-Gini distributed annually. There is an even higher differ- index with respect to the crop use metrics. The Gini ence between the crops considering the development index is the most commonly used inequality index of new cultivars. 21,434 potato varieties were released (Gini Index, 2008), known foremost for the quantifi- during a five-year period in comparison with only 21 cation of global income inequality. The 1-Gini index, new cassava varieties per five years. presented here, ranges from 0 to 1, where 0 reflects very unequal distribution across world regions and 1 Khoury et al. (2022) illustrated the supply of germ- reflects a completely equal global distribution across plasm by using the number of accessions available regions. It reflects the security of crop cultivation and in ex situ collections around the world, with respect use, where, for example, small indices of production to the crop genus and the most important species of and thus geographic restriction go hand in hand the respective crop. They also assessed the number of with a higher vulnerability of supply, for example to accessions (again with respect to genus and species) natural disasters. The percentage of potato acces- available under the multilateral system (MLS) of the sions safety duplicated at the SGSV is 43% and thus Plant Treaty. This assessment was done first, directly, relatively high, while there are no safety duplicated as notation (in MLS/not in MLS) in the public online cassava accessions. The equality of the distribution databases Genesys, FAO WIEWS and GBIF. Secondly, across the worlds’ regions with respect to global pro- the availability of accessions was assessed by consid- duction is 0.05 for potatoes and 0.04 for cassava. This ering whether the country hosting the institution is consistent with the fact that more countries produce that held the respective germplasm collection was a potatoes than cassava, as stated above. Food supply of signatory to the Plant Treaty, in which case the acces- potatoes is more equally distributed throughout the sion was regarded as available via the MLS. According world, with an equality of distribution value of 0.20, to databases, global ex situ collections count a total compared to a value of only 0.07 for cassava. 142 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Annex Table 2 .1 . Selected metrics collected by Khoury et al. (2022) for potatoes and cassava, subdivided by indicator domain. Metric Potatoes Cassava Potatoes / Cassava Crop use Global production [tons] 362,697,957 254,352,835 143% Food supply (Amount consumed) [g/capita/day] 94 39 241% Percentage of countries producing crop * 74% 48% 154% Percentage of countries consuming (being supplied with) crop * 100% 62% 161% Quantity exported globally [t] 18,287,593 39,015,830 47% Number of publications between 2009-2019, including patents and citations, searching title of publication (Google scholar search hits) 16,500 4,220 391% for genus ** Number of publications between 2009-2019, including patents and citations, searching title of publication (Google scholar search hits) 6,160 3,120 197% for species *** Interdependence Interdependence of global production from germplasm from primary centers of diversity [0-1] **** 98% 89% 110% Interdependence of global food supply from germplasm from primary centers of diversity [0-1] **** 100% 94% 106% Demand Accessions distributed from gene banks (Annual average 2014- 2017) 13,483 1,388 971% Variety releases in 5 years (2014-2018) 21,434 21 102,067% Supply Number of accessions in ex situ collections of genus ** 122,252 18,886 647% Number of accessions in ex situ collections of species *** 27,750 17,831 156% Accessions of the genus ** available through Multilateral System (MLS) directly noted in databases [%] 32% 35% 91% Accessions of the species *** available through Multilateral System (MLS) directly noted in databases [%] 45% 34% 132% Accessions of the genus ** available through Multilateral System (MLS) indirectly by matching institute countries with party status 84% 89% 94% [%] Accessions of the species *** available through Multilateral System (MLS) indirectly by matching institute countries with party status 88% 91% 97% [%] Security Accessions of genus ** safety duplicated in Svalbard Global Seed Vault [%] 14% 0%   Accessions of species *** safety duplicated in Svalbard Global Seed Vault [%] 43% 0%   1-GINI index for equality of production across the world [0-1] ***** 0.05 0.04 125% 1-GINI index for equality of food supply across the world [0-1] ***** 0.20 0.07 286% * Counting countries which list the crop as within top 95 % (FAOSTAT); Calculated as: Number of countries counting crop (top 95%) / Total number of countries (production 216, food supply 175) ** Potatoes: Solanum; Cassava: Manihot *** Potatoes: Solanum tuberosum, Solanum ajanhuiri, Solanum juzepczukii and Solanum curtilobum; Cassava: Manihot esculenta **** Global metric / Metric at primary center of diversity ***** Relative equality of crop use across world regions (same regions as used in interdependence domain), high equality give high indicator value GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 143 144 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Annex 3 . Number and category of potato accessions EST006 EST019 DEU159 NOR061 CZE027 POL002 NLD037 POL047 POL003 RUS001 BLR016 IRL036 BEL023 CAN064 ROM007 UKR026 GBR251 UKR008 USA004 ESP016 CUB005 ARM059 JPN183 BGR001 ROM018 ROM028 MEX208 PAN147 FRA010 CHE001 COL017 PHL303 ECU023 BRA020 Number of accessions PER001 PER867 100 - 500 PER860 BOL317 500 - 1000 100) Wild CHL179 1000 - 2500 300) Tradional culvar/Landrace CHL071 400) Breeding/research material 5700 - 6700 500) Advanced/Improved culvar not specified Figure A3. Number and category of potato accessions listed for each institute having > 100 accessions in the World Information and Early Warning System on Plant Genetic Resources for Food and Agriculture (WIEWS) ©FAO 2021, http://www.fao.org/wiews/en/, accessed on 20 Sept 2021. GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 145 Annex 4 . Potato germplasm collections classified as wild species Table Annex 4 Potato germplasm collections classified as wild species in the World Information and Early Warning System on Plant Genetic Resources for Food and Agriculture (WIEWS). WIEWS ©FAO 2021, http://www.fao.org/wiews/en/, accessed on 20th Sept 2021. Species name according to WIEWS were transferred to those names accepted by Spooner et al. (2014). In addition, country of origin, ploidy level is provided for the nine largest collection holders. na, not accepted names were found at https://solanaceaesource.myspecies.info/; *cultivated species listed incorrectly Genebank species Accepted by Spooner Code Country Ploidy Total USA004 RUS001 PER001 DEU159 NLD037 GBR251 BLR016 UKR026 PER860 CZE027 BRA020 JPN183 POL003 et al. (2014) S. japonicum Lycianthes rantonnetii       1                           S. aemulans Solanum ×aemulans Bitter & Wittm. aem ARG 3x, 4x (2EBN) 20 18 1 S. blanco-galdosii Solanum ×blanco-galdosii Ochoa blg PER 2x (2EBN) 10 4 4 1 1 S. doddsii Solanum ×doddsii Correll dds BOL 2x (2EBN) 41 16 8 4 4 3 3 1 2 S. michoacanum Solanum ×michoacanum (Bitter) Rydb. mch MEX 2x 10 1 2 1 2 2 1 S. neoweberbaueri Solanum ×neoweberbaueri Wittm. nwb PER 3x 1 1 S. vallis-mexici Solanum ×vallis-mexici Juz. vll MEX 3x 6   1         1 3           S. acaule Solanum acaule Bitter acl ARG, BOL, PER 4x (2EBN), 1488 421 335 377 64 142 62 9 16 35 5     18 S. schreiteri (na) Solanum acaule Bitter acl ARG, BOL, PER 4x (2EBN), 1 S. uyunense (na) Solanum acaule Bitter acl ARG, BOL, PER 4x (2EBN), 2 1     Solanum acaule Bitter Total       1491 421 336 377 64 142 62 9 16 35 5 0 0 18 S. acroglossum Solanum acroglossum Juz. acg PER 2x (2EBN) 5 2 1 2 S. acroscopicum Solanum acroscopicum Ochoa acs PER 2x 35 4 3 16 1 1 10 S. lopez-camarenae Solanum acroscopicum Ochoa acs PER 2x 3 1 2     Solanum acroscopicum Ochoa Total       38 4 3 17 1 1 0 0 0 12 0 0 0 0 S. agrimoniifolium Solanum agrimonifolium Rydb. agf GUA, HON, MEX 4x (2EBN) 49 21 8 6 5 3 2 1 3 S. albicans Solanum albicans (Ochoa) Ochoa alb ECU, PER 6x (4EBN) 144 27 13 81 4 12 1 1 2 S. albornozii Solanum albornozii Correll abz ECU 2x (2EBN) 13 4 4 2 1 S. amayanum Solanum amayanum Ochoa amy PER 2x (2EBN) 7     4   2       1         S. anamatophilum Solanum anamatophilum Ochoa amp PER 2x (2EBN) 1 1 S. peloquinianum Solanum anamatophilum Ochoa amp PER 2x (2EBN) 4 4     Solanum anamatophilum Ochoa Total       5 0 0 5 0 0 0 0 0 0 0 0 0 0 S. andreanum Solanum andreanum Baker adr COL, ECU 2x (2EBN), 4x (4EBN) 80 43 5 10 4 S. paucijugum Solanum andreanum Baker adr COL, ECU 2x (2EBN), 4x (4EBN) 31 5 20 2 2 2 146 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Genebank species Accepted by Spooner Code Country Ploidy Total USA004 RUS001 PER001 DEU159 NLD037 GBR251 BLR016 UKR026 PER860 CZE027 BRA020 JPN183 POL003 et al. (2014) S. tuquerrense Solanum andreanum Baker adr COL, ECU 2x (2EBN), 4x (4EBN) 20 4 10 3 1 1     Solanum andreanum Baker Total       131 43 14 40 9 3 3 0 0 0 0 0 0 0 S. augustii Solanum augustii Ochoa agu PER 2x (1EBN) 4 4 S. ayacuchense Solanum ayacuchense Ochoa ayc PER 2x (2EBN) 3     1           2         S. Berthaultii Solanum berthaultii Hawkes ber ARG, BOL 2x (2EBN), 308 135 49 29 15 32 14 8 5 15 2 S. litusinum Solanum berthaultii Hawkes ber ARG, BOL 2x (2EBN), 2 2 S. tarijense Solanum berthaultii Hawkes ber ARG, BOL 2x (2EBN), 186 95 18 19 27 13 6 1 2     Solanum berthaultii Hawkes Total       496 135 144 49 34 59 27 14 6 0 15 0 0 4 S. boliviense Solanum boliviense Dunal G, BOL, in DC. blv AR PER 2x (2EBN) 307 222 9 10 11 18 4 29 2 S. megistacrolobum Solanum boliviense Dunal L, in DC. blv ARG, BO PER 2x (2EBN) 242 93 44 19 68 10 1 7 S. sanctae-rosae Solanum boliviense Dunal ARG, BOL, in DC. blv PER 2x (2EBN) 31 6 7 11 4 1 2     Solanum boliviense Dunal in DC . Total       580 222 108 54 37 97 18 30 5 7 0 0 0 0 S. bombycinum Solanum bombycinum Ochoa bmb BOL 4x 2 2     Solanum bombycinum Ochoa Total       2 0 0 2 0 0 0 0 0 0 0 0 0 0 , 4x S. alandiae Solanum brevicaule Bitter brc ARG, BOL, 2x (2EBN) PER (4EBN), 6x 63 12 18 7 12 10 3 (4EBN) ), 4x S. avilesii Solanum brevicaule Bitter brc ARG, BOL, 2x (2EBN PER (4EBN), 6x 13 2 4 3 3 1 (4EBN) S. brevicaule Solanum brevicaule Bitter brc ARG, BOL, 2x (2EBN), 4x PER (4EBN), 6x 632 551 8 14 7 13 13 20 1 (4EBN) 2EBN), 4x S. gourlayi Solanum brevicaule Bitter brc ARG, BOL, 2x ( PER (4EBN), 6x 229 119 22 62 14 8 3 (4EBN) 2x (2EBN), 4x S. hondelmannii Solanum brevicaule Bitter brc ARG, BOL, PER (4EBN), 6x 54 16 12 6 2 10 8 (4EBN) 2x (2EBN), 4x S. hoopesii Solanum brevicaule Bitter brc ARG, BOL, PER (4EBN), 6x 10 2 2 2 4 (4EBN) 2x (2EBN), 4x S. incamayoense Solanum brevicaule Bitter brc ARG, BOL, PER (4EBN), 6x 26 7 4 3 6 5 1 (4EBN) GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 147 Genebank species Accepted by Spooner Code Country Ploidy Total USA004 RUS001 PER001 DEU159 NLD037 GBR251 BLR016 UKR026 PER860 CZE027 BRA020 JPN183 POL003 et al. (2014) 2x (2EBN), 4x S. leptophyes Solanum brevicaule Bitter brc ARG, BOL, PER (4EBN), 6x 105 20 34 4 37 6 2 1 (4EBN) S. oplocense Solanum brevicaule Bitter brc ARG, BOL, 2x (2EBN), 4x PER (4EBN), 6x 188 46 81 14 23 9 13 2 (4EBN) S. saltense Solanum brevicaule Bitter brc ARG, BOL, 2x (2EBN), 4x PER (4EBN), 6x 4 1 1 1 (4EBN) S. setulosistylum Solanum brevicaule Bitter brc ARG, BOL, 2x (2EBN), 4x PER (4EBN), 6x 4 2 1 (4EBN) 2x (2EBN), 4x S. sparsipilum Solanum brevicaule Bitter brc ARG, BOL, PER (4EBN), 6x 220 41 58 45 33 25 6 8 3 (4EBN) S. spegazzinii Solanum brevicaule Bitter brc ARG, BOL, 2x (2EBN), 4x PER (4EBN), 6x 195 74 3 57 40 12 6 1 2 (4EBN) x (2EBN), 4x S. sucrense Solanum brevicaule Bitter brc ARG, BOL, 2 PER (4EBN), 6x 101 26 13 10 41 9 1 (4EBN) 2x (2EBN), 4x S. ugentii Solanum brevicaule Bitter brc ARG, BOL, PER (4EBN), 6x 14 6 2 3 2 1 (4EBN) S. vidaurrei Solanum brevicaule Bitter brc ARG, BOL, 2x (2EBN), 4x PER (4EBN), 6x 16 4 12 (4EBN) S. virgultorum Solanum brevicaule Bitter brc ARG, BOL, 2x (2EBN), 4x PER (4EBN), 6x 7 1 2 4 (4EBN) 2x (2EBN), 4x S. brevimucronatum (na) Solanum brevicaule Bitter brc ARG, BOL, PER (4EBN), 6x 1 (4EBN) 2x (2EBN), 4x S. ruiz-zeballosii (na) Solanum brevicaule Bitter brc ARG, BOL, PER (4EBN), 6x 14 2 9 2 (4EBN)     Solanum brevicaule Bitter Total       1896 551 387 245 193 287 100 57 25 8 20 0 0 9 S. buesii Solanum buesii Vargas bue PER 2x (2EBN) 27 3 22 2     Solanum buesii Vargas Total       27 3 22 2 0 0 0 0 0 0 0 0 0 0 148 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Genebank species Accepted by Spooner Code Country Ploidy Total USA004 RUS001 PER001 DEU159 NLD037 GBR251 BLR016 UKR026 PER860 CZE027 BRA020 JPN183 POL003 et al. (2014) S. bulbocastanum Solanum bulbocastanum Dunal in Poir. blb GUA, HON, MEX 2x (1EBN), 3x 219 54 41 7 37 19 14 16 14   17       S. burkartii Solanum burkartii Ochoa brk PER 2x 15 2 8 5 S. irosinum Solanum burkartii Ochoa brk PER 2x 7 2 5     Solanum burkartii Ochoa Total       22 2 2 13 0 0 0 0 0 5 0 0 0 0 S. cajamarquense Solanum cajamarquense Ochoa cjm PER 2x (1EBN) 27 2   17 1         7         S. abancayense Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 22 S. achacachense Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 8 1 1 1 4 1 S. ambosinum Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 26 3 12 8 3 S. aymaraesense Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 8 1 4 1 2 S. billhookeri Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 3 2 1 S. bukasovii Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 451 351 18 19 11 1 5 45 S. canasense Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 64 10 20 15 18 S. candolleanum Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 214 177 5 19 6 3 4 S. chillonanum Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 3 2 1 S. coelestispetalum Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 53 1 38 3 7 1 3 S. longiusculus Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 5 3 2 S. marinasense Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 67 3 43 5 1 8 7 S. multidissectum Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 35 16 9 8 1 S. orophilum Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 30 1 23 2 3 1 S. ortegae Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 3 2 1 S. pampasense Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 26 2 7 6 3 6 1 S. sarasarae Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 5 5 S. saxatilis Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 3 3 S. tapojense Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 9 9 S. tarapatanum Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 11 10 1 GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 149 Genebank species Accepted by Spooner Code Country Ploidy Total USA004 RUS001 PER001 DEU159 NLD037 GBR251 BLR016 UKR026 PER860 CZE027 BRA020 JPN183 POL003 et al. (2014) S. amabile (na) Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 1 1 S. catarthrum (na) Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 6 4 1 S. soukupii (na) Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 4 2 2 S. velardei (na) Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 8 1 4 1 2     Solanum candolleanum Berthault Total       1065 177 50 536 78 64 52 8 7 66 0 0 0 0 S. cantense Solanum cantense Ochoa cnt PER 2x (2EBN) 9 7 2 S. cardiophyllum Solanum cardiophyllum Lindl. cph MEX 2x (1EBN), 3x 102 11 55 4 16 3     10           ARG, BOL, S. arnezii Solanum chacoense Bitter chc BRA, PAR, 2x (2EBN), 3x 16 3 4 1 8 PER, URU ARG, BOL, S. calvescens Solanum chacoense Bitter chc BRA, PAR, 2x (2EBN), 3x 1 1 PER, URU ARG, BOL, S. chacoense Solanum chacoense Bitter chc BRA, PAR, 2x (2EBN), 3x 717 167 212 18 111 72 16 54 28 2 16 11 PER, URU ARG, BOL, S. tuberosum Solanum chacoense Bitter chc BRA, PAR, 2x (2EBN), 3x 154 5 1 1 18 108 PER, URU ARG, BOL, S. yungasense Solanum chacoense Bitter chc BRA, PAR, 2x (2EBN), 3x 16 2 6 2 3 3 PER, URU ARG, BOL, S. boergeri (na) Solanum chacoense Bitter chc BRA, PAR, 2x (2EBN), 3x 6 3 2 PER, URU ARG, BOL, S. dolichostigma (na) Solanum chacoense Bitter chc BRA, PAR, 2x (2EBN), 3x 4 1 2 PER, URU ARG, BOL, S. knappei (na) Solanum chacoense Bitter chc BRA, PAR, 2x (2EBN), 3x 4 3 PER, URU ARG, BOL, S. laplaticum (na) Solanum chacoense Bitter chc BRA, PAR, 2x (2EBN), 3x 1 PER, URU ARG, BOL, S. parodii (na) Solanum chacoense Bitter chc BRA, PAR, 2x (2EBN), 3x 9 3 1 1 2 PER, URU 150 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Genebank species Accepted by Spooner Code Country Ploidy Total USA004 RUS001 PER001 DEU159 NLD037 GBR251 BLR016 UKR026 PER860 CZE027 BRA020 JPN183 POL003 et al. (2014) ARG, BOL, S. subtilius (na) Solanum chacoense Bitter chc BRA, PAR, 2x (2EBN), 3x 8 5 1 1 PER, URU     Solanum chacoense Bitter Total       936 172 231 25 118 77 16 65 32 3 20 16 108 15 S. chilliasense Solanum chilliasense Ochoa chl ECU 2x (2EBN) 3 1   2                     S. ariduphilum Solanum chiquidenum Ochoa chq PER 2x (2EBN) 1 1 S. chiquidenum Solanum chiquidenum Ochoa chq PER 2x (2EBN) 33 5 18 1 9     Solanum chiquidenum Ochoa Total       34 5 0 19 1 0 0 0 0 9 0 0 0 0 S. chomatophilum Solanum chomatophilum Bitter chm ECU, PER 2x (2EBN) 124 15 1 77 9 5 2 13 S. huarochiriense Solanum chomatophilum Bitter chm ECU, PER 2x (2EBN) 11 10 1 S. jalcae Solanum chomatophilum Bitter chm ECU, PER 2x (2EBN) 10 6 4 S. pascoense Solanum chomatophilum Bitter chm ECU, PER 2x (2EBN) 6 4 2     Solanum chomatophilum Bitter Total       151 15 1 97 11 6 2 0 0 17 0 0 0 0 S. clarum Solanum clarum Correll clr GUA, MEX 2x 21 14 3   2     1 1           S. calacalinum Solanum colombianum Dunal col COL, ECU, PER, VEN 4x (2EBN) 1 1 S. colombianum Solanum colombianum Dunal col COL, ECU, PER, VEN 4x (2EBN) 212 91 10 38 16 2 S. moscopanum Solanum colombianum Dunal col COL, ECU, PER, VEN 4x (2EBN) 26 4 6 2 4 S. orocense Solanum colombianum Dunal col COL, ECU, PER, VEN 4x (2EBN) 4 2 1 1 S. otites Solanum colombianum Dunal col COL, ECU, PER, VEN 4x (2EBN) 7 1 6 S. subpanduratum Solanum colombianum Dunal col COL, ECU, PER, VEN 4x (2EBN) 3 1 1 1 S. sucubunense Solanum colombianum Dunal col COL, ECU, PER, VEN 4x (2EBN) 2 1 1 S. tundalomense (na) Solanum colombianum Dunal col COL, ECU, PER, VEN 4x (2EBN) 18 18     Solanum colombianum Dunal Total       273 91 18 72 19 8 0 0 0 0 0 0 0 0 S. commersonii Solanum commersonii Dunal cmm ARG, BRA, URU 2x (1EBN), 3x 259 37 19 42 27 15 2 2 77 S. contumazaense Solanum contumazaense Ochoa ctz PER 2x (2EBN) 6 1 4 1 S. Curtilobum* Solanum curtilobum Juz. & Bukasov cur BOL, PER 5x 3           1               GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 151 Genebank species Accepted by Spooner Code Country Ploidy Total USA004 RUS001 PER001 DEU159 NLD037 GBR251 BLR016 UKR026 PER860 CZE027 BRA020 JPN183 POL003 et al. (2014) S. demissum Solanum demissum Lindl. dms GUA, MEX 6x (4EBN) 742 164 134 14 175 76 59 5 67 10 12 S. semidemissum Solanum demissum Lindl. dms GUA, MEX 6x (4EBN) 4 3     Solanum demissum Lindl . Total       746 164 134 14 175 76 62 5 67 0 10 0 0 12 S. dolichocremastrum Solanum dolichocremastrum Bitter dcm PER 2x (1EBN) 37 4 1 24 3 2 3 S. ehrenbergii Solanum ehrenbergii (Bitter) Rydb. ehr MEX 2x (1EBN) 46 29 8 1 7 S. flahaultii Solanum flahaultii Bitter flh COL 4x 44 17 1 9 2 S. gandarillasii Solanum gandarillasii Cárdenas gnd BOL 2x (2EBN) 22 7 1 2 5 3 4 S. garcia-barrigae Solanum garcia-barrigae Ochoa gab COL 4x 3 1 1 S. gracilifrons Solanum gracilifrons Bitter grc PER 2x 4 3 1 S. guerreroense Solanum guerreroense Correll grr MEX 6x (4EBN) 24 2 5 1 3 1 1 2 2 5 1 S. hastiforme Solanum hastiforme Correll hsf PER 2x (2EBN) 8 7 1 S. hintonii Solanum hintonii Correll hnt MEX 2x 1 1 S. hjertingii Solanum hjertingii Hawkes hjt MEX 4x (2EBN) 76 13 24 3 8 4 5 8 11 S. hougasii Solanum hougasii Correll hou MEX 6x (4EBN) 55 10 9 9 6 2 7 4 6 1 S. huancabambense Solanum huancabambense Ochoa hcb PER 2x (2EBN) 28 5 6 6 5 2 3 1 S. humectophilum Solanum humectophilum Ochoa hmp PER 2x (1EBN) 5     3 1 1                 S. guzmanguense Solanum hypacrarthrum Bitter hcr PER 2x (1EBN) 4 3 1 S. hypacrarthrum Solanum hypacrarthrum Bitter hcr PER 2x (1EBN) 11 1 1 8 1     Solanum hypacrarthrum Bitter Total       15 1 1 11 1 0 0 0 0 1 0 0 0 0 S. immite Solanum immite Dunal imt PER 2x (1EBN), 3x 14 4 1 5 1 3 S. incasicum Solanum incasicum Ochoa ins PER 2x (2EBN) 2 2 S. infundibuliforme Solanum infundibuliforme Phil. inf ARG, BOL 2x (2EBN) 262 127 60 9 4 41 7 14             S. brachycarpum Solanum iopetalum (Bitter) Hawkes iop MEX 6x (4EBN) 60 13 22 3 13 1 7 S. iopetalum Solanum iopetalum (Bitter) Hawkes iop MEX 6x (4EBN) 99 59 4 8 4 4 3 12 2     Solanum iopetalum (Bitter) Hawkes Total       159 59 17 8 26 7 16 13 9 0 0 0 0 0 S. jamesii Solanum jamesii Torr. jam MEX, USA 2x (1EBN) 301 216 43 3 11 2 3 5 16 S. juzepczukii* Solanum juzepczukii Juz. juz ARG, BOL, PER 3x 1                           S. kurtzianum Solanum kurtzianum Bitter & Wittm. ktz ARG 2x (2EBN) 290 94 117 3 13 34 5 6 15 2 S. macolae (na) Solanum kurtzianum Bitter & Wittm. ktz ARG 2x (2EBN) 1     Solanum kurtzianum Bitter & Wittm . Total       291 94 117 3 13 34 5 6 15 0 0 0 0 2 S. angustifolium (na) Solanum lanzae       4                           152 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Genebank species Accepted by Spooner Code Country Ploidy Total USA004 RUS001 PER001 DEU159 NLD037 GBR251 BLR016 UKR026 PER860 CZE027 BRA020 JPN183 POL003 et al. (2014) S. laxissimum Solanum laxissimum Bitter lxs PER 2x (2EBN) 21 5 1 8 1 1 5 S. santolallae Solanum laxissimum Bitter lxs PER 2x (2EBN) 11 1 4 2 2 1 1     Solanum laxissimum Bitter Total       32 5 2 12 3 3 1 0 0 6 0 0 0 0 S. lesteri Solanum lesteri Hawkes & Hjert. les MEX 2x 18 3 7 3 1 3 S. lignicaule Solanum lignicaule Vargas lgl PER 2x (1EBN) 26 6 1 9 2 1 2 2 3 S. limbaniense Solanum limbaniense Ochoa lmb PER 2x (2EBN) 14 1 1 8 1 1 2 S. lobbianum Solanum lobbianum Bitter lbb COL 4x (2EBN) 12 3 1 4 S. longiconicum Solanum longiconicum Bitter lgc CRI, PAN 4x 34 10 1 8 1 2 S. maglia Solanum maglia Schltdl. mag ARG, CHL 2x, 3x 29 2 4 2 4 2 1 1 S. malmeanum Solanum malmeanum Bitter 0 ARG, BRA, PAR, URU 2x (1EBN), 3x 50 25                   25     S. medians Solanum medians Bitter med CHL, PER 2x (2EBN), 3x 109 13 4 61 3 5 4 1 17 S. sandemanii Solanum medians Bitter med CHL, PER 2x (2EBN), 3x 19 1 6 1 3 1 7 S. tacnaense Solanum medians Bitter med CHL, PER 2x (2EBN), 3x 23 12 1 10     Solanum medians Bitter Total       151 13 5 79 4 8 6 1 0 34 0 0 0 0 S. microdontum Solanum microdontum Bitter mcd ARG, BOL 2x (2EBN), 3x 307 114 34 14 44 41 26 3 7 1 1 S. simplicifolium (na) Solanum microdontum Bitter mcd ARG, BOL 2x (2EBN), 3x 21 7 4 7 2     Solanum microdontum Bitter Total       328 114 41 14 44 41 26 7 14 0 1 0 0 3 S. minutifoliolum Solanum minutifoliolum Correll min ECU 2x (1EBN) 18 1 3 2                     S. chancayense Solanum mochiquense Ochoa mcq PER 2x (1EBN) 15 8 2 2 3 S. mochiquense Solanum mochiquense Ochoa mcq PER 2x (1EBN) 41 6 4 13 7 4 3 2 1     Solanum mochiquense Ochoa Total       56 6 12 15 9 7 3 0 0 2 1 0 0 0 S. morelliforme Solanum morelliforme Bitter & Muench mrl BOL, GUA, MEX, HON 2x 33 19 3 4 4 1 S. multiinterruptum Solanum multiinterruptum Bitter mtp PER 2x (2EBN), 3x 118 8 5 84 6 1 14 Solanum neocardenasii S. neocardenasii Hawkes & Hjert. ncd BOL 2x 39 2 2 5 2 1 2 22 3           S. neorossii Solanum neorossii Hawkes & Hjert. nrs ARG 2x 32 6 5 3 4 4 8 1 1 S. hannemanii Solanum neorossii Hawkes & Hjert. nrs ARG 2x 9 1 8     Solanum neorossii Hawkes & Hjert. Total       41 6 5 3 5 12 8 1 1 0 0 0 0 0 S. neovavilovii Solanum neovavilovii Ochoa nvv BOL 2x (2EBN) 1 1 S. nubicola Solanum nubicola Ochoa nub PER 4x (2EBN) 3 1 2 S. okadae Solanum okadae Hawkes & Hjert. oka BOL 2x 89 16 9 8 4 13 9 24 6 S. oxycarpum Solanum oxycarpum Schiede oxc MEX 4x (2EBN) 42 20 6 4 10 2                 S. brevidens (na) Solanum palustre 23 4 2 GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 153 Genebank species Accepted by Spooner Code Country Ploidy Total USA004 RUS001 PER001 DEU159 NLD037 GBR251 BLR016 UKR026 PER860 CZE027 BRA020 JPN183 POL003 et al. (2014) S. paucissectum Solanum paucissectum Ochoa pcs PER 2x (2EBN) 20 3 1 11 1 4 S. pillahuatense Solanum pillahuatense Vargas pll PER 2x (2EBN) 2 2 S. pinnatisectum Solanum pinnatisectum Dunal pnt MEX 2x (1EBN) 233 19 67 1 36 10 12 37 34 12 4 S. piurae Solanum piurae Bitter pur PER 2x (2EBN) 19 3 3 6 3 1 3 S. polyadenium Solanum polyadenium Greenm. pld MEX 2x 83 18 25 5 7 6 7 7 2 1 S. raphanifolium Solanum raphanifolium Cárdenas & Hawkes rap PER 2x (2EBN) 195 37 16 86 14 14 10 6 12 S. raquialatum Solanum raquialatum Ochoa raq PER 2x (1EBN) 3     3                     S. rhomboidei- Solanum lanceolatum rhomboideilanceolatum rhl PER 2x (2EBN) 5 3 2 Ochoa Solanum S. ancophilum (na) rhomboideilanceolatum rhl PER 2x (2EBN) 7 7 Ochoa Solanum     rhomboideilanceolatum       12 0 0 10 0 0 0 0 0 2 0 0 0 0 Ochoa Total S. scabrifolium Solanum scabrifolium Ochoa scb PER 2x 2 1 1 S. schenckii Solanum schenckii Bitter snk MEX 6x (4EBN) 35 15 2 4 9 1 3 S. simplicissimum Solanum simplicissimum Ochoa (1989b) smp PER 2x (1EBN) 4 3 1 S. sogarandinum Solanum sogarandinum Ochoa sgr PER 2x (2EBN), 3x 24 2 1 14 2 3 1     1         S. brachistotrichum Solanum stenophyllidium Bitter sph MEX 2x (1EBN) 34 16 5 1 12 S. stenophyllidium Solanum stenophyllidium Bitter sph MEX 2x (1EBN) 51 25 13 9 2 1     Solanum stenophyllidium Bitter Total       85 25 29 9 7 2 0 12 0 0 0 0 0 0 S. capsicibaccatum Solanum stipuloideum Rusby stp BOL 2x (1EBN) 18 4 7 2 5 S. circaeifolium Solanum stipuloideum Rusby stp BOL 2x (1EBN) 28 1 9 5 6 7 S. stipuloideum Solanum stipuloideum Rusby stp BOL 2x (1EBN) 26 14 12     Solanum stipuloideum Rusby Total       72 14 1 12 13 12 8 7 5 0 0 0 0 0 S. fendleri Solanum stoloniferum Schltdl. sto MEX, USA 4x (2EBN) 127 52 18 7 24 9 12 4 S. papita Solanum stoloniferum Schltdl. sto MEX, USA 4x (2EBN) 69 36 7 6 1 14 5 S. polytrichon Solanum stoloniferum Schltdl. sto MEX, USA 4x (2EBN) 101 44 12 5 16 9 10 4 S. stoloniferum Solanum stoloniferum Schltdl. sto MEX, USA 4x (2EBN) 921 520 103 48 94 10 52 8 52 13 1 13 S. ajuscoense (na) Solanum stoloniferum Schltdl. sto MEX, USA 4x (2EBN) 2 1 S. antipoviczii (na) Solanum stoloniferum Schltdl. sto MEX, USA 4x (2EBN) 6 4 S. malinchense (na) Solanum stoloniferum Schltdl. sto MEX, USA 4x (2EBN) 1 S. neoantipoviczii (na) Solanum stoloniferum Schltdl. sto MEX, USA 4x (2EBN) 26 1 23 1 1 S. tlaxcalense (na) Solanum stoloniferum Schltdl. sto MEX, USA 4x (2EBN) 2 1 1     Solanum stoloniferum Schltdl . Total       1255 520 241 48 131 28 92 51 90 0 13 0 1 27 154 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Genebank species Accepted by Spooner Code Country Ploidy Total USA004 RUS001 PER001 DEU159 NLD037 GBR251 BLR016 UKR026 PER860 CZE027 BRA020 JPN183 POL003 et al. (2014) S. suaveolens Solanum suaveolens  6 5 S. tarnii Solanum tarnii Hawkes & Hjert. trn MEX 2x 25 11 7 3 4 S. trifidum Solanum trifidum Correll trf MEX 2x (1EBN) 57 14 13 1 18 3 1 2 4 S. trinitense Solanum trinitense Ochoa trt PER 2x (1EBN) 1     1                     Landraces Solanum tuberosum from W S. andigenum* ‘Andigenum group’ tbr Venezuela 4x (4EBN) 14 14 tetraploids South to N Argentina Landraces S. phureja* Solanum tuberosum from W ‘Andigenum group’ diploids tbr Venezuela 2x (2EBN) 15 1 1 South to N Argentina Landraces S. stenotomum* Solanum tuberosum from W ‘Andigenum group’ diploids tbr Venezuela 2x (2EBN) 10 South to N Argentina Landraces S. leptostigma (na) Solanum tuberosum from W ‘Chilotanum group’ tbr Venezuela 4x (4EBN) 2 1 South to N Argentina Landraces from W S. Ochoanum (na) ‘Chilotanum group’ tbr Venezuela 4x (4EBN) 1 South to N Argentina Landraces S. parvicorollatum (na)* Solanum tuberosum from W ‘Chilotanum group’ tbr Venezuela 4x (4EBN) 1 South to N Argentina Landraces S. rybinii* Solanum tuberosum from W ‘Andigenum group’ diploids tbr Venezuela 2x (2EBN) 3 3 South to N Argentina GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 155 Genebank species Accepted by Spooner Code Country Ploidy Total USA004 RUS001 PER001 DEU159 NLD037 GBR251 BLR016 UKR026 PER860 CZE027 BRA020 JPN183 POL003 et al. (2014)     Solanum tuberosum Andigenum group Total       46 0 1 0 0 1 0 18 0 0 0 0 0 0 S. venturii Solanum venturii Hawkes & Hjert. vnt ARG 2x (2EBN) 22 4 3 2 6 3 2 1 1 S. vernei Solanum vernei Bitter & Wittm. vrn ARG 2x (2EBN) 192 35 36 10 24 22 7 32 23   3       S. macropilosum Solanum verrucosum Schltdl. ver MEX 2x (2EBN), 3x, 4x 3 2 1 S. verrucosum Solanum verrucosum Schltdl. ver MEX 2x (2EBN), 3x, 4x 163 43 34 8 12 18 20 3 15 6 2     Solanum verrucosum Schltdl . Total       166 43 34 8 14 19 20 3 15 0 6 0 0 2 S. urubambae Solanum violaceimarmoratum Bitter vio BOL, PER 2x (2EBN) 14 11 2 S. violaceimar- Solanum violaceimarmoratum moratum Bitter vio BOL, PER 2x (2EBN) 28 7 2 6 3 4 5 1 Solanum     violaceimarmoratum Bitter       42 7 2 17 3 4 5 1 0 2 0 0 0 0 Total S. wittmackii Solanum wittmackii Bitter wtm PER 2x (1EBN) 38 29 1 8 S. woodsonii Solanum woodsonii Correll wds PAN 4x 4     4                     S. etuberosum Solanum etuberosum Lindl. 59 30 5 1 5 1 8 S. fernandezianum Solanum fernandezianum Phil. 20 7 1 3 4 2 S. palustre Solanum palustre Schltdl. 158 71 9 3 5 10 1     Solanum sect . Etuberosum Total       237 108 15 0 4 12 6 20 0 0 1 0 0 0 S. juglandifolium Solanum sect. Juglandifolia 19 S. coriaceifoliolatum (na) 4 1 1 1 S. fraxinifolium 9 1 S. garciae 8 5 1 1 S. gibberulosum 46 10 33 2 S. hawkesianum 5 5 S. ingifolium 2x (1EBN) 1 1 S. pamiricum 6 5 1 S. schickii         7   5         1             Total 14400 3946 2530 2428 1324 1228 654 560 454 282 130 118 109 104 156 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO Annex 5 . Collection of landraces maintained in national and international genebank Table Annex 5 Collection of landraces maintained in national and international genebanks and listed in data the World Information and Early Warning System on Plant Genetic Resources for Food and Agriculture (WIEWS). WIEWS ©FAO 2021, http://www.fao.org/wiews/en/, accessed on 20th Sept 2021. Species name according to WIEWS and species name accepted by Spooner et al. (2014) including country of origin, ploidy level is provided for nine largest collection holder. na, not accepted names were found at https://solanaceaesource.myspecies.info/; *species classified incorrectly by genebanks. Genebank species Accepted by Spooner et al . (2014) Code Country Ploidy Total PER001 RUS001 DEU159 BOL317 COL017 USA004 PER867 CHL071 GBR251 Solanum ajanhuiri Solanum ajanhuiri Juz . & Bukasov ahj BOL, PER 2x (2EBN) 98 14 9 8 64 1 Solanum megistacrolobum* Solanum boliviense Dunal in DC. blv ARG, BOL, PER 2x (2EBN) 2 2 Solanum suaveolens* (na) Solanum campylacanthum Hochst. ex A.Rich. 1 1 Solanum multidissectum Solanum candolleanum Berthault buk PER 2x (2EBN), 3x 1 1 Solanum curtilobum Solanum curtilobum Juz . & Bukasov cur BOL, PER 5x 121 26 80 7 Solanum xcurtilobum see Dodds, 1962 Solanum curtilobum cur BOL, PER 5x 30 8 14 16 Solanum etuberosum* Solanum etuberosum Lindl. 16 16 Solanum juzepczukii Solanum juzepczukii Bukasov juz ARG, BOL, PER 3x 163 3 128 1 Solanum xjuzepczukii see Dodds, 1962 Solanum juzepczukii Bukasov juz ARG, BOL, PER 3x 28 31 12 16 Solanum juzepczukii Bukasov Total 191 31 3 12 128 0 1 16 0 0 Landraces from W Solanum chaucha Solanum tuberosum ‘Andigenum group’ triploids tbr Venezuela South to N 3x 131 4 Argentina Solanum phureja Solanum tuberosum ‘Andigenum Landraces from W group’ diploids tbr Venezuela South to N 2x (2EBN) 335 197 88 6 Argentina Landraces from W Solanum stenotomum Solanum tuberosum ‘Andigenum group’ diploids tbr Venezuela South to N 2x (2EBN) 369 108 248 Argentina Solanum stenotomum Solanum tuberosum ‘Andigenum Landraces from W subsp. goniocalyx group’ diploids tbr Venezuela South to N 2x (2EBN) 166 110 14 33 Argentina Solanum tuberosum subsp. Solanum tuberosum ‘Andigenum Landraces from W andigena group’ tetraploids tbr Venezuela South to N 4x (4EBN) 7845 3308 1215 975 672 940 528 Argentina Solanum tuberosum Group Solanum tuberosum ‘Andigenum Landraces from W Andigena group’ tetraploids tbr Venezuela South to N 4x (4EBN) 326 324 Argentina Solanum stenotomum Solanum tuberosum ‘Andigenum Landraces from W subsp. stenotomum group’ diploids tbr Venezuela South to N 2x (2EBN) 450 287 86 77 Argentina Solanum tuberosum Andigenum group Total 9622 3902 200 1315 1229 672 940 638 0 324 GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 157 Genebank species Accepted by Spooner et al . (2014) Code Country Ploidy Total PER001 RUS001 DEU159 BOL317 COL017 USA004 PER867 CHL071 GBR251 Solanum tuberosum subsp. Solanum tuberosum L. ‘Chilotanum tuberosum group’ tbr CHL (Chilean landraces) 4x (4EBN) 1281 173 405 59 23 48 492 Solanum tuberosum Group Solanum tuberosum L. ‘Chilotanum Tuberosum group’ tbr CHL (Chilean landraces) 4x (4EBN) 9 9 Solanum tuberosum L . ‘Chilotanum group’ Total 1290 173 0 405 59 23 48 0 492 9 Solanum andigenum (na) Solanum tuberosum ‘Andigenum group’ tetraploids  tbr   4x (4EBN) 2705 2701 Solanum goniocalyx (na) Solanum tuberosum ‘Andigenum group’ diploids tbr 2x (2EBN) 60 54 6 Solanum phureja subsp. Solanum tuberosum ‘Andigenum Phureja (na) group’ diploids tbr 2x (2EBN) 625 229 396 Solanum rybinii (na) Solanum tuberosum ‘Andigenum group’ diploids tbr 2x (2EBN) 246 246 Solanum yabary (na) Solanum tuberosum tbr 1 1 Solanum x chaucha (not Solanum tuberosum ‘Andigenum found) group’ triploids tbr 3x 135 127 14 115 Solanum tuberosum Solanum tuberosum tbr 1021 25 47 2 1 Solanum tuberosum Group Solanum tuberosum ‘Andigenum Phureja group’ diploids tbr 2x (2EBN) 3 3 Solanum tuberosum Group Solanum tuberosum ‘Andigenum Stenotomum group’ diploids tbr 2x (2EBN) 3 3 Solanum tuberosum Total 4799 127 3002 268 6 396 47 115 2 1 Total       16171 4255 3243 2022 1567 1091 1044 785 510 340 Annex 6 . Consultation agenda Consultation to discuss the Global Strategy for the Conservation of Potato (GSPC) 10-12 November 2021 10 November 2021 – 14:00–15:45 CET Topic 1: Taxonomy 14:00–14:30 Manuela Nagel: Introduction and overview of the GSPC 14:30–14:55 Taxonomy: Potato taxonomy Keynote speaker: Dr. Iris Edith Peralta (Argentina) 14:55–15:00 5 Minute Break 15:00–15:45 Discussion Topic 1 10 November 2021 – 16:00–18:00 CET Topic 2: Conservation management 16:00–16:15 Manuela Nagel: Recent challenges in the conservation management 16:15–16:55 Reports of the curators CIP potato collections – Dr. Manrique, Norma (CIP, Peru) Management at the CGN – Dr. Roel Hoekstra (CGN, The Netherlands); Conservation at Embrapa – Dr. Caroline M. Castro (Embrapa, Brazil) 16:45–16:55 Short Questions and Answers 16:55–17:00 5 Minute Break 17:00–17:45 Discussion Topic 2 17:45–18:00 Summary and conclusions of the day 11 November 2021 – 14:00–15:45 CET Topic 3: Gap analysis 14:00–14:30 Manuela Nagel: Welcome, short survey summary about gaps in the collections 14:30–14:55 Gap analysis: The spatial gap analysis for potato landraces Keynote speaker: Prof. Dr. Julian Ramirez-Villegas (Alliance of Bioversity International and CIAT, Italy) 14:55–15:00 5 Minute Break 15:00–15:45 Discussion Topic 3 11 November 2021 – 16:00–18:00 CET Topic 4: Data quality and safety 16:00–16:15 Manuela Nagel: Overview on data availability and challenges 16:15–16:45 Data management and tools for collection management Keynote speaker: Matija Obreza (CropTrust, Germany) 16:45–16:50 5 Minute Break 16:50–17:35 Discussion Topic 4 158 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO 12 November 2021 – 14:00 –15:45 CET Topic 5: Breeding 14:00–14:30 Manuela Nagel: Overview on usability of the collections 14:30–14:55 Breeding: Genome design of hybrid potato Keynote speaker: Dr. Chunzhi Zhang (CAAS, Shenzen, China) 14:55–15:00 5 Minute Break 15:00–15:45 Discussion Topic 5 12 November 2021 – 16:00–17:15 CET Topic: Action Points for GSPC 16:00–16:20 Future priorities for the ex situ conservation of potato Zoom Breakout Group: Taxonomy & miscellaneous Zoom Breakout Group: Conservation management & miscellaneous Zoom Breakout Group: Gap filling & miscellaneous Zoom Breakout Group: Data safety & miscellaneous Zoom Breakout Group: Breeding & miscellaneous 16:20–16:45 Reports from each Breakout Group (max 5 minutes each) 16:45–17:15 Summary and conclusions of the meeting GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO | 159 GENERAL CONTACT THE CROP TRUST MEDIA CONTACT +49 (0) 228 85427 122 Platz Der Vereinten Nationen 7 +49 (0) 228 85427 141 info@croptrust .org 53113 Bonn, Germany media@croptrust .org 160 | GLOBAL STRATEGY FOR THE CONSERVATION OF POTATO