柿属植物3种及栽培柿17个品种的抗寒性

用电解质渗出率法和示差热分析法（DTA）测定了柿属植物（Diospyros)3个种及栽培柿（D.kaki)17个品种的抗寒性。结果表明，柿属植物种间抗寒性存在着很大差异。而栽培柿品种间抗性差异不大，供试材料中，君迁子D.lotus最为抗寒，其中D.lotus♂的抗寒性为－29．1℃，D.lotus♀的为－28．6℃，其次为栽培柿D.kaki，供试17个品种的抗寒性范围在－21．0－－27．0℃之间；原产于亚热带地区的台东豆柿D.taitoensis最不抗寒，仅耐－16．5℃低温。降温速度对于树体冻害影响极大，若气温降至某一低,则到达该温值所用时间越长，树体受低温伤害越重，低温驯化可在某种程度上提高柿品种的抗寒性，此外，供试材料抗寒性的强弱与其是否为甜或涩品种无关。

Freezing Resistances of Three Diospyros Species and Seventeen Kaki Cultivars

The freezing resistance of three Diospyros species and seventeen cultivars of D.kaki was evaluated by the differential thermal analysis (DTA) and electrolyte leakage from the tissues after freezing treatments. The results showed that the difference of freezing resistance between the three Diospyros' was significant, but there was no significant differnce among the kaki cultivars. The hardiest species during the coldest period of the season was D.lotus(♂ was -29.1℃, ♀ was-28.6℃)followed by D.kaki (-21.0～-27.0℃)，and the least hardy was D.taitoensis(-16.5℃)which is distributed in subtropical Taiwan. The rate of temperature decreasing significantly affected the trees' freezing resistance. The duration to attain some low injury temperature was shown to be of significance: the resalts showed that, the more the duration was long, the more the trees suffered from freezing injury. To some degree, cold acclimation could increase the freezing resistanes of kaki cultivars. No relationship was found between freezing resistance and sweet or astringent cultivars of Japanese persimmons.