引言龙眼(Dimocarpus Iongan Lour)为我国南方特产,是重要的亚热带果树之一。它喜温忌冻,即使在南亚热带地区栽培,冬季亦常罹冻害,尤其遇周期性冻害,龙眼的生长与结果更受严重影响。近二十年来,鉴于植物细胞膜因低温作用透性加大,细胞内电解质外渗增加,这种变化明显地出现在外部形态之先,因而可用电导法来测定其耐寒性。但对于龙眼的耐寒性研究,过去仅以植株枝叶受冻表现来描述。 Introduction Dimocarpus Iongan Lour is a specialty of the South China and is one of the most important subtropical fruit trees. It likes to keep away from frost. Even in the South Subtropical Region, frost damage often occurs in winter, especially in the case of periodic frost damage. The growth and consequences of longan are more seriously affected. In the recent two decades, due to the increased permeability of plant cell membranes due to low temperature, the extracellular electrolyte extravasation increased obviously in the external morphology. Therefore, the cold resistance of the plant membrane can be measured by the conductivity method. However, the research on the cold tolerance of longan has only been described in the past with the freezing performance of plant branches and leaves.