云锦杜鹃低温半致死温度对自然降温的适应

The adaptation of Rhododendron Fortunei's semilethal temperature to natural temperature falling

以云锦杜鹃为材料,研究了其叶片低温半致死温度与膜保护系统随气温下降的变化.结果表明,低温半致死温度降低的同时,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性增强,使膜保护系统自由基的清除能力增强,超氧化物阴离子自由基(O2-)水平降低,丙二醛(MDA)含量降低.膜保护系统的适应性变化导致低温半致死温度的降低是抗寒性提高的生理基础.

Investigations are made into the changes of the semilethal temperature and membrane protective system of the leaves of Rhododendran Foetunei Linell. As temperature falls, the results show that the semilethal temperature decreases. The activity of SOD and CAT increases, thus strengthening the ability of the membrane's protective system to scavenge free radicles. In this way, the level of O2-and the content of MDA decreases. The decline of the semilethal temperature caused by the membrane protective system is the physiological basis to improve cold resistance.