Cryopreservation of date palm highly regenerable tissues using vitrification procedures
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Fki, L.; Sahnoun, N.; Bouaziz, N.; Bouattour, O.; Guarbaya, M.; Saidi, M. N.; Gargouri Bouzid, R.; Drira N.; Panis B. -2011-Cryopreservation of date palm highly regenerable tissues using vitrification procedures -ISHS 908-p. 219-226
Permanent link to this item: http://hdl.handle.net/10568/42409
Internet URL: http://www.actahort.org/books/908/908_27.htm
Date palm genetic resources are today subject to severe erosion due to the spread of lethal diseases like 'bayoud' and the extension of the monoclonal cultivations. In view of this critical situation, and also due to the high cost and risks of in situ conservation, the preservation of date palm genetic resources has become an important topic. Safe storage of this germplasm can be achieved through the application of a wide variety of tissue culture techniques, among them cryopreservation. In the first part of this work, we investigated date palm somatic embryogenesis and caulogenesis. Such study is important to ensure the availability of highly regenerable tissues which can be used for cryogenic treatments. In date palm, buds and proembryogenic masses (PEMs) can be induced from several explants and low concentrations of 2,4-D. The maintenance of the in vitro-cultured multiple bud clusters and the proembryos by successive subcultures could, however, increase the risk of genetic and physiological variations. The cryopreservation of this kind of material soon after their initiation is therefore necessary and will be a practical and effective way to produce certified in vitro plants with a genetic conformity. Next, we studied the cryopreservation of these highly proliferating meristem cultures and proembryos using the ultra-rapid droplet freezing and the encapsulation-vitrification methods. These techniques, based on a high-speed cooling of the dehydrated meristems and proembryos, proved to be efficient. Survival rates of about 60% could be obtained for Barhee cultivar PEMs that are treated for 30 min with the PVS2 solution. Moreover, we observed that the cryogenic treatment does not affect the morphogenetic capacity of the tissues and fifty in vitro plants could be regenerated. The morphological and molecular analyses do not show polymorphisms of the cryopreserved tissues.