大白菜耐热性的生理研究＊Ⅱ．叶片水分和蛋白质代谢与耐热性

通过测定耐热性不同的３个大白菜品种在高温胁迫下发生的水分和蛋白质代谢的变化，表明耐热的亚蔬１号比不耐热的“１０６”品种叶细胞具有更高的含水量和束缚水、较大的气孔密度和蒸腾速率、较低的蛋白质降解速率，较耐热的华湘１号的各项生理指标均居于中间水平．高温使细胞膜透性稍有增大，耐热与不耐热品种膜透性增大可能有不同机理．高温胁迫使耐热品种脯氨酸含量迅速增多，脯氨酸可作为大白菜耐热性鉴定的生化指标

A Study on the Physiology of Heat Tolerance in Chinese Cabbage Ⅱ. Metabolism of Water and Proteins in Leaves and Heat Tolerance

The changes of the metabolism of water and proteins in the leaves of 3 cultivars of Chinese cabbage (heat tolerant Yashu No.[KG-4〗1, less heat tolerant Huaxiang NO.[KG-4〗1 and heat sensitive “106”) under high temperature stress were studied. The results showed that the leaf cells in Yashu No.[KG-4〗1 held more water content and bound water, with higher stomatal density,faster transpiration rate and lower degradation rate of proteins than those in “106”. The changes of the physiological indexes in Huaxiang No.[KG-4〗1 were at intermediate levels as compared with those of the other two cultivars.The cell membrane permeability increased slightly under high temperature stress in the three cultivars, which probably had different mechanisms between the heat tolerant and the heat sensitive. High temperature stress caused a rapid increase of proline content which can be used as a biochemical index in the identification of heat tolerance of Chinese cabbage.