A NOVEL PRECULTURING FOR ENHANCING THE SURVIVAL OF IN VITRO-GROWN MERISTEMS OF WASABI (WASABIA-JAPONICA) COOLED TO -196-DEGREES C BY VITRIFICATION

Successful cryopreservation of wasabi meristems by vitrification has b een achieved by preculture with 0.3 M sucrose for 16 hr and subsequent cryoprotective treatment with a mixture of 2 M glycerol plus 0.4 M su crose for 20 min at 25 degrees C before dehydration with a vitrificati on solution (PVS2), The preculture with a mixture of 0.3 M sucrose and 0.5 M glycerol for 16 hr at 25 degrees C without subsequent cryoprote ction produced very high level of shoot formation as high as about 85 %. Thus, this preculture method significantly simplified the vitrifica tion procedure. It was also observed that the contents of sucrose and glycerol along with proline greatly increased in the precultured meris tems. The new preculture may increase the applicability of cryopreserv ation to less resistant materials.