Plant recovery of cryopreserved apical meristem-tips of Melia azedarach L. using encapsulation/dehydration and assessment of their genetic stability

A cryopreservation process usingencapsulation/dehydration technique was setup for apical meristem-tips of invitro plantlets of `paradise tree' (Melia azedarach L. var. gigantea,clone `El dorado'). Apical meristem-tipswere cultured for one day on MS basalmedium with 2 M BA and 0.5 M IBAand encapsulated with 3% sodium alginate.The highest shoot proliferation rate aftercryopreservation was obtained whenencapsulated apical meristem-tips werepregrown for 3 days in liquid medium with0.5, 0.75 and 1 M of sucrose for 24 hoursprogressively, desiccated for 5 hours withsilicagel followed by rapid or slowcooling. Survival after freezing in liquidnitrogen ranged between 67–83% andshoot proliferation ranged between 43–60%. This cryopreservation treatmentpreserved genetic stability, when it wasevaluated using the electrophoreticpatterns of nine isozyme systems and RAPDprofiles.