STUDIES ON CRYOPRESERVATION AND PLANT REGENERATION OF STRAWBERRY CALLUS

Callus was induced within 4 weeks from strawberry (Fragaria×ananassa Duchcv. Redcoat) embryos on a modified MS medium with 4 mg/16-benzylamino purine (6-BA) and 0.1 mg/l naphthy acetatic acid (NAA), then frozen either gradually or directly at cooling velocities and stored to -20, -40, and -70℃ in dimethy sulfoxide (DMSO) and glycerol (GLY) as protectants at concentration of 5%, 10%, and 15% respectively. Effect model of various cryoprotectants on the frequency of cell survival is DMSO+GLY>DMSO>GLY. Shoots formed from the callus by both slowly and rapidly thawing methods, but the plant regeneration frequency of the former is higher than that of the latter. The different results were obtained when the callus stored in DMSO, GLY or both mixture.