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Survival of in Vitro Cultured Tissue of ‘Jonathan’ Apples Exposed to −196°C


Shoot tip explants taken from proliferating cultures of apple (Malus domestica ‘Jonathan’) survived freezing to −196°C in the presence of cryoprotectants. Regrowth following freezing to −196° was in the form of callus growth, indicating that the meristems were injured to such an extent that organized growth of the shoot meristem was precluded. A cold acclimation period of up to 6 weeks at 4° in the dark was required to obtain acceptable survival levels. Glycerol generally was more effective than DMSO in providing cryoprotection to cold acclimated shoot tips.