CRYOPRESERVATION OF IN VITRO-GROWN GOOSEBERRY AND CURRANT MERISTEMS

Apical meristems from in vitro-grown plants of currant and gooseberry (Ribes) germplasm were successfully cryopreserved using a variety of t echniques. Modifications of slow freezing, vitrification and encapsula tion-dehydration were compared. Slow freezing at 0.3 or 0.5 degrees C/ min following pregrowth on 5% DMSO and cryoprotection with PGD produce d moderate to high survival. Vitrification in PVS2 following pregrowth on sorbitol and a 20-minute pretreatment resulted in low to moderate survival, while pregrowth on 5% DMSO improved survival for two of the three genotypes tested. Modification of the vitrification procedure wi th a pretreatment similar to that used in slow freezing was not effect ive. Encapsulation-dehydration with an 18-hour preculture with 0.75 M sucrose and 3 hrs of dehydration was very effective.