CRYOPRESERVATION OF BANANA (MUSA SPP) MERISTEM CULTURES AFTER PRECULTURE ON SUCROSE

A simple cryopreservation method is described for the long term-conser vation of banana meristem cultures. It involves preculturing the proli ferating meristems for 2-4 weeks on Murashige and Skoog medium, enrich ed with 0.3-0.5 M sucrose. Surviving meristematic clumps are then exci sed and transferred to cryotubes and plunged directly into liquid nitr ogen for storage. The protocol was initially optimised for meristem cu ltures of the cultivar Bluggoe (Musa spp.; ABB group) and gave a viabi lity rate of up to 42.5%. A reduction of the moisture content by expos ure of the meristematic clumps to the sterile air flow of a laminar ai r flow bench did nor result in an increased survival rate. This cryopr eservation method was tested on seven banana cultivars belonging to di fferent genomic groups and resulted in viability rates between 12 and 72% depending on the cultivar. Microscopical observations revealed tha t only the most meristematic parts of the proliferating clumps survive d freezing. Copyright (C) 1996 Elsevier Science Ireland Ltd.