SHORT COMMUNICATION Journal of Plant Pathology https://doi.org/10.1007/s42161-024-01804-y caused by Colletotrichum spp. significantly limits the crop’s production potential (Dania and Gbadamosi 2019). Sev- eral Colletotrichum spp. cause anthracnose in almost all crops. In the case of cowpea, CAD pathogens can survive in soils, dead plants, and in seeds for few years (Awurum and Ucheagwu 2013). CAD can begin in the seedling stage and spread within and between fields through rain splash, irrigation, and wind (Ntahimpera et al. 1997). Symptoms include reddish-brown streaks on leaves and round to irreg- ular necrotic lesions on leaves, stems, and pods (Enyiukwu et al. 2020). CAD can be effectively managed with some synthetic fungicides, plant extracts, biocontrol agents, and resistant varieties (Masangwa et al. 2013; Shiny et al. 2015; Ganiyu et al. 2018; Dania and Gbadamosi 2019). However, diffi- culties in using taxonomic characters to identify Colletotri- chum spp. can be a limiting factor to recommend effective management methods and, therefore, molecular character- ization is a must (Weir et al. 2012). Comparing sequences of at least three genes is needed for proper Colletotrichum spp. identification (Liu et al. 2016; Giacomin et al. 2021). Several Colletotrichum spp. have been identified as causal agents of CAD globally, including C. dematium (Banyal and Cowpea ([Vigna unguiculata (L.) Walp.)] is an important legume for household nutrition in sub-Saharan Africa (SSA) and a source of income and employment for many people in rural Nigeria (Kebede and Bekeko 2020). Many farmers prefer growing cowpea because it thrives under low input production systems and fixes atmospheric nitrogen in the soil that benefits subsequent crops (Nyaga and Njeru 2020). The grains, rich in protein, carbohydrates, vitamins, and minerals, are an excellent option for diet diversification, especially in areas relying heavily on cereal-based diets (Boukar et al. 2015). Nigeria is the largest cowpea producer worldwide (FAO- STAT 2020). However, cowpea anthracnose disease (CAD) Alejandro Ortega-Beltran a.beltran@cgiar.org 1 Institute of Agricultural Research and Training, Obafemi Awolowo University, Ile-Ife, Nigeria 2 Department of Crop Protection and Environmental Biology, University of Ibadan, Ibadan, Nigeria 3 International Institute of Tropical Agriculture, Ibadan, Nigeria Abstract Cowpea (Vigna unguiculata (L.) Walp.) is an important multipurpose crop in various countries in sub-Saharan Africa. However, cowpea production is affected by cowpea anthracnose disease (CAD). In Nigeria, Colletotrichum lindemuthi- anum and C. destructivum have been described as causal agents of CAD based on morphological features. Such char- acterization is unreliable because many similarities among and within Colletotrichum spp. exist. In the current study, Colletotrichum spp. were isolated from leaves showing CAD symptoms collected in farmers’ fields across four states in Nigeria. Isolates were characterized using morphological keys, severity scores in detached leaf assays, and sequencing of the ITS, ACT, GADPH, TUB, ApMat, and CAL genes. Two species, C. chrysophilum and C. siamense, were identified after comparing multigene sequences. Morphological characteristics and disease symptoms were very similar for both spe- cies. However, severity scores varied among and within species. Both C. chrysophilum and C. siamense are reported for the first time as causal agents of CAD across the globe. The accurate diagnosis of organisms causing CAD in the studied region will allow developing effective management strategies. Keywords Anthracnose · Colletotrichum · Cowpea · Diagnosis · Phylogeny Received: 3 August 2023 / Accepted: 29 October 2024 © The Author(s) 2024 Studies of Colletotrichum species causing cowpea anthracnose in Nigeria reveal two first-time reports globally Adenike O. Dada1,2,3 · Victor O. Dania2 · Olaniyi A. Oyatomi3 · Michael Abberton3 · Alejandro Ortega-Beltran3 1 3 http://orcid.org/0000-0003-3747-8094 http://crossmark.crossref.org/dialog/?doi=10.1007/s42161-024-01804-y&domain=pdf&date_stamp=2024-11-15 Journal of Plant Pathology Kumar 2012), C. fructicola (Atghia et al. 2015), C. lindemu- thianum (Pradhan et al. 2018) and C.destructivum (Satpathy and Beura 2021). Both C. lindemuthianum and C. destruc- tivum were reported to cause CAD in Nigeria (Onesirosan and Barker 1971; Williams 1975; Enyiukwu et al. 2020) but no molecular characterization was done. Here we report causal agents of CAD in the middle belt region of Nige- ria. Morphological features, pathogenicity, and sequences of six genes were compared. The results can contribute to the development of effective strategies to manage CAD in Nigeria. In September and October 2018, farmers’ fields were sur- veyed in the states of Niger, Kogi, and Nasarawa, and the Federal Capital Territory (FCT (Suppl. Fig. 1; hereinafter referred as the four states, even though FCT is not a state per se). Three fields were surveyed in each of three local government areas per state. Ten leaves with CAD symp- toms were randomly collected in each field, placed in brown bags, labeled, and taken to the laboratory at IITA-Ibadan for pathogen isolation and characterization. About 3-mm at the advancing edges of lesions were cut and surface steril- ized in 1% NaOCl for 1 min. Leaf pieces were rinsed in three changes of sterile water for 1 min before drying using sterile paper towel. Dried leaf pieces were plated on potato dextrose agar (PDA) and incubated at 28 °C (3–5 days). Iso- lates morphologically similar to Colletotrichum spp. were sub-cultured on PDA for 7 days. Initial identification was done based on cultural and spore descriptions (Damm et al. 2010). Seventy-two isolates were obtained, single-spored, and stored at -80 °C in 15% glycerol for further analysis. Morphological characterization included radial growth rate on PDA, malt extract agar (MEA), and Sabouraud agar, the colony color, spore type, and shape. The pathogenicity of the isolates was tested in a detached leaf assay. Plants (76 total) of CAD susceptible variety, ‘Ife Brown’, were grown in the screenhouse for three weeks with adequate watering. Inocula were prepared from 18 representative isolates grown in PDA for 7 days. Cultures were scrapped off the medium surface with sterile water into sterile beakers and the suspensions filtered through sterile cheesecloth. Spore count was done using an hemocytome- ter, adjusted to 106 spores/ml, and supplemented with 1 ml/l 20% TWEEN®20. Crisper boxes (31 × 23 × 10 cm) were sterilized with 2% NaOCl, rinsed with two changes of sterile water, and drained under a biosafety cabinet. Cotton wool and paper towels wrapped in aluminum foil were autoclaved (121 °C, 15 min) and then laid in equal proportion in the boxes. Fif- teen ml sterile water were added to each box before placing three surface sterilized leaves with the abaxial side exposed. Leaves were inoculated with 40 µl spore suspensions, using one isolate per box. The process was repeated for all 18 isolates. Healthy leaves in the control box were treated with sterile water. The experiment was laid in a completely ran- domized design and replicated thrice. CAD symptoms were monitored, and disease severity was recorded from second day after inoculation (DAI). A disease severity scale of 1 to 5 where 1 = 0–5% leaf area affected and 5 = more than 50% leaf area affected was used, as described by Nwadili et al. (2017). To extract genomic DNA, mycelia from 7-day-old PDA cultures of the 18 isolates were independently transferred into 15 ml vials with potato dextrose broth and placed on an Edmund Bühler KL2 shaker for 72 h at 28 °C. DNA was extracted with the Zymo Quick-DNA/RNA™ Miniprep Kit (Zymo Research Corp., Irvine, CA, USA). The inter- nal transcribed spacer (ITS) region, and actin (ACT), glyc- eraldehyde-3-phosphate (GADPH), beta-tubulin (TUB), calmodulin (CAL), and intergenic spacing and partial mat- ing-type (mat 1–2) (ApMat) genes were studied. The prim- ers used were ITS4/ITS5 (White et al. 1990), ACT512F/ ACT783R (Carbone and Kohn 1999), GDF/GDR (Temple- ton et al. 1992), BT1/BT2B (Glass and Donaldson 1995), CL1C/CL2C (Weir et al. 2012), and CgDL-F6/CgMAT1F2 (Rojas et al. 2010). Each PCR tube had 2 µl DNA and 10.5 µl cocktail mix (0.25 µl 10 mM dNTPs, 0.75 µl 25 mM MgCl2, 0.25 µl 10 pMol primer pair, 0.06 µl Taq polymerase, 2.5 µl green buffer mix, and 6.44 µl RNase-free sterile water). PCR conditions included 5 min of initial denaturation at 94 °C, followed by 35 cycles of 30 s denaturation at 94 °C, 30 s primer annealing temperatures at 55 °C for ITS, 58 °C for ACT, 59 °C for both CAL and TUB, 56 °C for GADPH, and 53 °C for ApMat, followed by 1 min extension at 72 °C, and a 5 min final extension at 72 °C. Electrophoresis was done on a 1.5% agarose gel (100 V, 1 h). After ethanol purification, all amplicons were sequenced bidirectionally with an ABI 3130xl Genetic Analyser (Applied Biosystems) by the Bioscience Centre, IITA- Ibadan. Sequences were assembled using BioEdit software and verified via the BLAST search tool (ncbi.nlm.nih. gov/). Sequences of the 18 isolates were aligned alongside those of 17 reference Colletotrichum spp. (Table 1). The 35 sequences were trimmed to equal lengths. Polymorphic regions were marked in each region across the species. Trimmed sequences were concatenated (2,889 positions in the final dataset), and a single phylogenetic tree inferred using the Maximum Likelihood method and Tamura-Nei model (Tamura and Nei 1993) was obtained using the Molecular Evolutionary Genetics Analysis (MEGA) soft- ware v11. After assignment to their corresponding species, the iso- lates were subjected to pathogenicity tests. A total of 76 plants of ‘Ife Brown’ variety were grown as above. Spore suspensions of the 18 isolates were prepared as above and 1 3 Journal of Plant Pathology sprayed on all plant parts using a high-pressure sprayer on 2-week-old plants. Control plants were sprayed with sterile water. The experiment was laid in a randomized complete block design (RCBD) with four replicates per treatment. All plants were covered with transparent plastic bags for 24 h to increase humidity and aid in the establishment of infection. Disease severity was scored each 7th day from the first DAI up to 12 weeks after inoculation. A modified scale of Latunde-Dada (1990) was used where 0 = no infec- tion; 0.5 = hypersensitive spots on main stem only; 1 = small lesions on main stem and petioles of lower leaves; 2 = lesions on stem, petioles, and branches; 3 = advanced lesions on stem, petioles, branches, and veins on the abaxial surfaces of leaves; 4 = severe infection with lesions on stem, peti- oles, branches, leaf veins, and peduncles; and 5 = advanced lesions on stem, petioles, branches, and leaf veins, spread- ing lesions on peduncles and pods. Yield data was collected on weight of pods, average length of five longest pods, num- ber, and grain weight. Grains were weighed using a Ohaus SP202 balance (OHAUS Instruments, Shanghai, China). Pod length was measured using a standard meter rule. Mean severity scores were used to calculate the area under disease progress curve (AUDPC) using the formula AUDPC = ∑n−1 i=1 0.5 (yi+1 + yi) (ti+1 + ti) (Campbell and Madden 1990) where “ti” is the time (days after planting) at ith observation, “yi” is the percent of an assessment of Table 1 Details and GenBank sequence accessions of reference Colletotrichum isolates used to determine phylogenetic relatedness of Colletotri- chum species causing cowpea anthracnose disease in middle belt states of Nigeria Isolate/Strain ID Species DNA regiona and NCBI GenBank accession number ITS TUB ACT CAL GAPDH ApMat NFUCF-214 C. fructicola OR056217 OR073852 OR096466 OR096539 OR069501 OR105838 NFUCF-118 C. fructicola OR056214 OR073849 OR09646 OR096536 OR069498 OR105835 NFUCF-179 C. fructicola OR056216 OR073851 OR096465 OR096538 OR069500 OR105837 NFUCF-95 C. fructicola OR056213 OR073848 OR096462 OR096535 OR069501 OR105834 NFUCF-74 C. fructicola OR056212 OR073847 OR096461 OR096534 OR069497 OR105833 W-1/GS03 C. siamense OQ771887 OQ759587 OQ759555 OQ759564 OQ759579 KC790676 G1-3/Col-1834 C. siamense OQ771888 OQ759588 OQ759556 OQ759563 OQ759580 MZ568781 CBS:125,378/ITCC6152/C1316.5 C. siamense JX010278 JX010410 JX009441 JX009709 JX010019 KC790703 ICMP:17,785/ b120/C1259.2 C. siamense JX010272 JX010391 JX009446 JX009706 JX010058 MW14222 DAR:76,934/Col-1929/SYCo2 C. siamense JX010270 MW583638 JX009535 JX009707 JX010002 MZ568783 AFK17 C. chrysophilum MN625458 MN622860 MN622831 MN622859 MN632506 MN62287 AFK31 C. chrysophilum MN625452 MN622863 MN622837 MN622852 MN653161 MN62281 C95/CPO 27.845 C. chrysophilum MZ562291 MN848366 MN741052 MZ562255 MN737345 MZ562282 C86/AREC3a C. chrysophilum MZ562288 MT513054 MN741048 MZ562252 MT512986 MZ562279 C53/CMS-6760 C. chrysophilum MZ562285 MN741068 MN741045 MZ562249 MN741090 MZ562276 Ninomiya_5/GD-LO3 C. gloeosporioides LC811975 LC812149 LC812144 HM575330 LC812147 LC812146 LF916 C. gloeosporioides KJ955226 KJ955371 KJ954493 KJ954777 KJ954927 KJ954629 CC1 C. chrysophilum OQ254724 OQ259589 OQ259537 OQ259564 OQ259570 PQ570534 CC2 C. chrysophilum OQ254725 OQ259588 OQ259538 OQ259552 OQ259571 PQ570535 CC3 C. chrysophilum OQ254726 - - OQ259553 OQ259572 PQ570536 CC4 C. chrysophilum - OQ259590 OQ259539 OQ259554 OQ259573 PQ570537 CC5 C. chrysophilum OQ254727 OQ259591 OQ259540 OQ259555 OQ259574 PQ570538 CC7 C. chrysophilum OQ254728 OQ259592 OQ259541 OQ259556 OQ259575 PQ570539 CC10 C. chrysophilum OQ254729 OQ259593 OQ259546 OQ259565 OQ259576 PQ570540 CC11 C. chrysophilum OQ254730 OQ259594 OQ259542 OQ259557 OQ259577 PQ570541 CC12 C. chrysophilum OQ254731 OQ259595 OQ259543 OQ259558 OQ259578 PQ570542 CC13 C. chrysophilum OQ254732 OQ259596 OQ259544 OQ259559 OQ259579 PQ570543 CC14 C. chrysophilum OQ254733 OQ259597 OQ259547 OQ259560 OQ259580 PQ570544 CC15 C. chrysophilum OQ254734 OQ259598 OQ259548 OQ259561 OQ259581 PQ570545 CC16 C. chrysophilum OQ254735 - OQ259545 OQ259566 OQ259582 PQ570546 CC22 C. chrysophilum OQ254736 OQ259599 OQ259549 OQ259562 OQ259583 PQ570547 CC23 C. chrysophilum OQ254737 OQ259600 OQ259550 OQ259563 OQ259584 PQ570548 CC6 C. siamense OQ254739 OQ259601 OQ259551 OQ259567 OQ259585 PQ570549 CC8 C. siamense OQ254740 - - OQ259568 OQ259587 PQ570550 CC9 C. siamense OQ254741 OQ259602 - OQ259569 OQ259586 PQ570551 aITS: internal transcribed spacer; TUB: beta-tubulin; ACT: actin; CAL: calmodulin; GADPH: glyceraldehyde-3-phosphate; ApMat: intergenic spacing and partial mating-type 1 3 Journal of Plant Pathology 15 ambiguous isolates grouped within the C. chrysophi- lum clade. Both C. chrysophilum and C. siamense isolates formed distinct, well supported clades with bootstrap values of 74% and 100%, respectively (Fig. 4) and both clearly separated from C. gloeosporioides isolates, which served as an outgroup. In our study, the ApMat marker was critical to distinguishing isolates in the C. gloeosporioides species complex, as in other studies (Silva et al. 2012; Doyle et al. 2013). Overall, the ApMat locus yielded the largest number of polymorphisms among all the loci examined (Table 2). The C. chrysophilum isolates were present in all four states: five isolates each from Niger and FCT, three from Nasar- awa, and two from Kogi. The C. siamense isolates were from Kogi, one isolate, and Niger, two isolates. Similarity index revealed 81% similarities between C. siamense and C. chrysophilum isolates (Fig. 3). In the pathogenicity assay, CAD symptoms occurred on all inoculated plants. Symptoms included reddish brown vein streaks on leaves and stems, white to slight pink/ orange necrosis with reddish brown halo on leaves, and brown blotch on pods (Suppl. Fig. 3). All isolates produced similar symptoms, but severity varied among isolates in the same species (Suppl. Table 2). Similarly, the two spe- cies have been reported to produce similar symptoms in papaya (Zhang et al. 2021; Pacheco-Esteva et al. 2022), and avocado (Fuentes-Aragón et al. 2020). As expected, con- trol plants had the highest yield parameters (Suppl. Table 2) and disease severity scores were negatively correlated with yield (Suppl. Table 3). The yield parameters had a sig- nificant positive correlation (>70%) with each other. The negative relationship between the disease severity and yield suggests that both C. chrysophilum and C. siamense can the disease at the ith observation and “n” is the total number of observations. Analysis was carried out using SAS v9.2 (SAS Institute, Cary, NC, USA). For yield data, means were subjected to analysis of variance (ANOVA) and separated using Duncan’s Multiple Range Test (DMRT; α = 0.05). Relationships between AUDPC and yield were determined using Pearson Correlation test. All isolates exhibited morphology typical of the C. gloeo- sporioides species complex, characterized by colonies that were either fluffy white or dense black with concentric ring patterns on PDA. The colonies’ edges were either smooth or irregular and sometimes had orange or dark acervuli, with sectoring present in some isolates (Fig. 1). The spores were single-celled with a central mark that sometimes looked double-celled (Suppl. Fig. 2). Dark setae were seen in few isolates. The colony characteristics changed with sub-cul- turing and radial growth varied across the different media (Suppl. Table 1). CAD symptoms on inoculated leaves were reddish brown necrotic lesions (Fig. 2) that appeared from the second DAI in all the leaves. The lesion size on the leaves progressed for each isolate daily until the experiment was terminated at day 7. Initially, a BLAST search conducted with sequences of ITS, ACT, GADPH, TUB, and CAL revealed 15 isolates with >95% identity to C. chrysophilum/C. fructicola and three with >95% identity with C. siamense. Phylogenetic analysis using these five loci yielded inconclusive results in differentiating C. fructicola from C. chrysophilum (tree not shown). To resolve this, we sequenced the ApMat locus for the 15 unassigned isolates and those belonging to C. sia- mense. In the phylogenetic analysis using all six loci, all Fig. 1 Cultures grown on potato dextrose agar (PDA), malt extract agar (MEA), and Sabouraud agar of Colletotrichum siamense isolate CC6 (a, b, c, respectively) and of C. chrysophilum isolate CC1 (d, e, f, respectively) 1 3 Journal of Plant Pathology valuable information for the design of CAD control strate- gies in Nigeria. In Nigeria, CAD was initially attributed to C. lindemu- thianum (Onesirosan and Barker 1971; Williams 1975). However, Bailey et al. (1990) reported a CAD pathogen unrelated to C. lindemuthianum and Latunde-Dada et al. (1996) reported a CAD pathogen having close similarities with C. destructivum, with ovoid, slightly pointed apex, and truncate base spores. Those features were not detected in isolates from the present study, which have ovoid spores significantly reduce yield in susceptible cowpea varieties. Both species have been reported to cause significant dam- age in apple (Khodadadi et al. 2020; Chen et al. 2022) and avocado (Fuentes-Aragón et al. 2020). The current study reports for the first time C. chrysophi- lum and C. siamense causing CAD worldwide. This report is based on morphological keys, pathogenicity assessment, and molecular tools. There were no isolates belonging to either C. lindemuthianum or C. destructivum, previously reported to cause CAD in Nigeria. Our report provides Fig. 2 Anthracnose symptoms on cowpea leaves inoculated with Colletotrichum siamense isolate CC6 (a) and C. chrysophilum isolate CC1 (b) on the 5th day after inoculation. Sterile distilled water was used to inoculate the negative control leaves (c) 1 3 Journal of Plant Pathology Ta bl e 2 C om pa ris on o f I TS , c al m od ul in (C A L) , a nd g ly ce ra ld eh yd e- 3- ph os ph at e (G A D PH ) s eq ue nc es o f C ol le to tr ic hu m c hr ys op hi lu m a nd C . s ia m en se is ol at es fr om N ig er ia (w ith p re fix C C ) an d is ol at es re tri ev ed fr om N C B I G en B an ka Is ol at e ID IT S TU B C A L G A PD H A C T A pM at 39 60 39 70 84 11 0 11 2 25 0 37 0 15 0 26 2 32 6 35 8 36 5 36 6 36 9 46 5 47 5 47 6 49 0 61 6 17 4 18 2 77 1 6 7 11 12 14 15 16 17 20 22 24 25 C . c hr ys op hi lu m C T A G A T G C G C G C G T C C C T G G C C G C A C G T A G C C C T G C A C C 1 C T A G A T G C G G G C G T C C C T G G C C G C A C G T A G C C C T G C A C C 2 C T A G A T G C G G G C G T C C C T G G C C G C A C G T A G C C C T G C A C C 3 C T A G A T G C G G G C G T C C C T G G C C G C A C G T A G C C C T G C A C C 5 C T A G A T G C G G G C G T C C C T G G C C G C A C G T A G C C C T G C A C C 10 C T A G A T G C G G G C G T C C C T G G C C G C A C G T A G C C C T G C A C C 11 C T A G A T G C G G G C G T C C C T G G C C G C A C G T A G C C C T G C A C C 15 C T A G A T G C G G G C G T C C C T G G C C G C A C G T A G C C C T G C A C C 16 C T A G A T G C G G G C G T C C C T G G C C G C A C G T A G C C C T G C A C C 22 C T A G A T G C G G G C G T C C C T G G C C G C A C G T A G C C C T G C A C C 23 C T A G A T G C G G G C G T C C C T G G C C G C A C G T A G C C C T G C A C . s ia m en se T C T T T C - T A A A T A G T T T A T A T T A T T A A A G - - - T C A T G C C 6 T C T T T C - T A A A T A G T T T A T A T T A T T A A A G - - - T C A T G C C 8 T C T T T C - T A A A T A G T T T A T A T T A T T A A A G - - - T C A T G C C 9 T C T T T C - T A A A T A G T T T A T A T T A T T A A A G - - - T C A T G a In e ac h lo ci , n uc le ot id e po si tio n w he re p ol ym or ph is m s o cc ur re d ar e in di ca te d 1 3 Journal of Plant Pathology (Fig. 4), both belonging to the C. gloeosporioides spe- cies complex. The previously reported CAD pathogens in Nigeria, C. destructivum and C. lindemuthianum, belong to the C. destructivum and C. orbiculare species complexes, respectively. Methods to manage CAD in Nigeria have focused on C. lindemuthianum and C. destructivum (Ganiyu et al. 2018; Dania and Gbadamosi 2019; Enyiukwu et al. 2021). Those methods need to be tested against the species reported in the current study. The findings stress the need to investigate the prevalent Colletotrichum spp. causing CAD in other regions to develop appropriate control strategies in Nigeria. In addi- tion, the large cowpea collection at IITA Genetics Resource Centre should be tested for their resistance to C. chrysophi- lum, C. siamense, and other Colletotrichum spp. that may be interacting with cowpea across Nigeria and elsewhere. and straight round ends and fit the description of multiple Colletotrichum spp.: C. gloeosporioides, C. siamense, C. fructicola, C. cliviicola, C. chrysophilum, C. lindemuthi- anum, and C. destructivum (Gao et al. 2018; Sun and Liang 2018; Khodadadi et al. 2020; Pérez-Mora et al. 2021; Rodrí- guez-Palafox et al. 2021; Dada et al. 2022; Ma et al. 2023). Our results concur with observations made by Sharma and Shenoy (2014) that spore characteristics are not reliable to distinguish C. gloeosporioides species complex members. Because C. lindemuthianum was reported to cause CAD in Nigeria, we initially used two primer pairs specific to this species, CD1/CD2 (Chen et al. 2013) and C1F432/ C1R533 (Wang et al. 2008). However, none of the 18 iso- lates amplified either primer pair. The 6-loci phylogenetic analysis employed allowed revealing that 15 isolates belong to C. chrysophilum and the other three to C. siamense Fig. 3 Identity matrix of concat- enated sequence of ITS, GADPH, beta-tubulin, calmodulin actin, and ApMat genes of Colletot- richum siamense (CC6, CC8, and CC9) and C. chrysophilum isolates (rest of the isolates) caus- ing cowpea anthracnose in the sampled states in Nigeria 1 3 Journal of Plant Pathology Funding Funding was provided by Global Crop Diversity Trust and Genebank Initiative of the One CGIAR supported by CGIAR Fund Donors (https://www.cgiar.org/funders/). Data availability The partial gene sequences from this study are available in NCBI-GenBank under the following accession numbers: ITS region OQ254724 to OQ254741; beta-tubulin OQ259588 to OQ259602; actin OQ259537 to OQ259551; calmodulin OQ259552 to OQ259569; GADPH OQ259570 to OQ259587; and ApMat PQ570534 to PQ570551. Declarations Competing interests The authors declare no competing interests. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit h t t p : / / c r e a t i v e c o m m o n s . o r g / l i c e n s e s / b y / 4 . 0 / . 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