Effects of Cold Acclimation and Freezing Solution Treatment on the Survival of Frozen Lateral Buds Excised from in vitro-Cultured Shoots of Tara vine (Actinidia arguta)

Lateral buds excised from in vitro culture-derived shoots of tara vine (Actinidia arguta) were subjected to pretreatments in freezing solutions and cold acclimation, and finally to freezing in liquid nitrogen to obtain fundamental knowledges for cryopreservation of plants. 1. A high survival rate after freezing and thawing was obtained in buds cold-acclimated at 5°C for 4 weeks followed by 0°C-2 weeks. 2. The following conditions were thought to be optimal for the pretreatment of lateral buds : a) 15% DMSO in freezing solution, b) 1 hour in the freezing solution and c) freezing solution kept at 0°C. 3. Fifty percent of the cold-acclimated lateral buds survived after being treated for 60 min in a freezing solution of 15% DMSO and 8 M or 11.5 M glycerine and prefrozen to -30°C at 0.5°C/min, and then immersed in liquid nitrogen for 2 hrs.