Browsing by Author "Malaurie, B."

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    Cryopreservation as a Tool for the Management of Coconut Germplasm
    (2011) Malaurie, B.; N'Nan, O.; Bandupriya, H.D.D.; Borges, M.; Verdeil, J.L.; Tregear, J.
    We present hereafter a review of different collaborative research studies carried out on the cycopreserntion of coconut plumules excised from the zygotic embryo. Plumule (shoot apical meristem and leaf primordia) tissues have shown different degrees of success in cropresen ation depending on th combination of alginate encapsulation and osmotic or evaporative dehydration used. The percentage of regrowth was progressi\\ Cly impro\\ ed from vitrification (0%), to osmoprotection (10%), and subsequently the encapsulation-dehydration technique allowed 20% regrowth level into leafy shoots. Addition of abscisic acid (20 to 40 JI:\\I) boosted recovery growth after freezing (up ta 40%). Histological studies have clearly shown that the addition of lower amounts of ABA (10 JIM) allows cells to maintair. the structural characteristics of control cells for immersion into liquid nitrogen without dehydration. The effect of plant material conditioning, for transport from collecting site to laboratories, was studied to identify possible effects of unc( ntrolled factors on tissue tolerance to cryopreservation. Three conditioning methods lemb o set in endosperm core (ALB); emb,·yo transferred onto of solidified agar (5W); emb, o immersed into KCI solution (KCI)I were u~ed. 5W performance is clearl~ more efficient when combined with dehydration and freezing. giving 40% recovc . These results are interesting as they show that the medium surrounding the ~mb 1 (endosperm or medium supply) can be replaced by agar alone. without nutritive factors. This approach should also facilitate germrlasm exchanf e. As a result of the absence of phloem vascular bundles in the plumular tissues, the approach described here should increase the scope for obtai.ling material free of pathogenic agents, an essential prerequisite for the conserntion and exchange of germ plasm. This approach should be a strong point in the fight lIgainst Lethal Yellowing Disease. the most serious disease affecting coconut plantations.
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    Efficient Method of Transporting Coconut (Cocos nucifera L.) Zygotic Embryos for Cryopreservation of Plumules by Encapsulation/Dehydration
    (2014) Bandupriya, H.D.D.; Fernando, S.C.; Verdeil, J.L.; Malaurie, B.
    Coconut is both socially and economically important crop in tropical and subtropical countries, thus the conservation of existing diversity of its germplasm is vital to maintain biodiversity, sustain crop production and utilisation of germplasm for crop improvement strategies. The recalcitrant storage behavior and large size of the coconut seed make it impossible to use as a germplasm storage material. Cryopreservation is an ideal means of long-term storage of germplasm which offers long-term storage capability with minimal storage space and maintenance requirements. The coconut embryo has been now adapted by various researchers for the purpose of germplasm exchange and it is now being routinely applied in germplasm collection and exchange activities with sufficient germination rates. The aim of the present study was to determine the effect of different coconut embryo transport! storage methods [as solid endosperm plugs under cold temperature, embryos cultured in Solidified Agar Medium (SAM) or KCI solution under room temperature] on cryopreservation of plumules using encapsulation/dehydration method. The results revealed that plumules excised from embryos transported/ stored in SAM and pretreated with 1.0M sucrose could be cryopreserved with 71.8% survival and 56% recovery rates. The survival and recovery could be further increased up to 77.5% and 65% respectively by supplementation of I.OM sucrose with 20 uM ABA.