Studies on Relationship Between Low Temperature Exotherms and Freezing Injury in Stem Tissues and Flower Buds of Mei Flower and David's Peach

摘要

Differential thermal analysis was utilized to determine midwinter hardiness of stem tissues and flower buds of mei flower (Prunus mume) and David’s peach (Prunus davidiana). Low temperature freezing exotherms were found to occur at -35℃ in Green Calyxs’ David’s peach and -18℃ in mei flower. A Low temperature exotherm was produced by the freezing of deep supercooling water which was detected in the wood tissues but not in the bark. Freezing processes of the wood and those of the bark appeared to be independent. Deep supercooling points of both species were found to be closely related to freezing injury and to their respective distributions.