Preservation of Several Plant Tissue Cultures by Freezing(Papers presented at the 34th Annual Meeting, April 1988, Tokyo)

Abstract

The freezing conditions of several plant tissue cultures, which have been preserved by subculturing of callus on solid medium were investigated in order to establish the method for long-term preservation. The cultured plant cells used were Datura innoxia, Rosa hybrida, Daucus carota, Nicotiana tabacum and Vinca rosea. They were cultured at 27℃ in dark for a week and used for the following studies. When the cooling rate was lowered than 1℃/min, the viability was not increased. Nor the hardening at 4℃ for 4 weeks was effective. The viability was high when cells were frozen in the solution of cryoprotectants, Murashige and Skoog medium + 5% DMSO + 10% glucose + 0.6M mannitol. When the viability and recovery growth were examined after storage at -80℃ and -135℃ in the mechanical freezer and at -190℃ in the vapor phase of liquid nitrogen, the storage at -135℃ seemed to be the best. The viabilities of the protoplasts of Datura innoxia and Vinca rosea, which were freeze-sensitive in the form of callus, were about 4 times and 17 times higher, respectively than that of callus after freezing to -40℃ at a cooling rate of 1℃/min and storaged at -190℃ for 18 hr.