蒙古沙冬青对不同土壤水分条件的生理生态响应

Physiological and Ecological Responses of Ammopiptanthus Mongolicus to Different Soil Water Conditions

蒙古沙冬青(Ammopiptanthus mongolicus)是分布在干旱荒漠地区的常绿阔叶灌木植物,具有独特的干旱环境适应机制。研究结果表明,浇水前后蒙古沙冬青的光合生理和水分生理特征发生了明显变化。浇水后,老龄、中龄和幼龄蒙古沙冬青的蒸腾速率日均值分别增大了29.33%、18.41%和89.53%,光合速率日均值分别减小了30.06%、24.68%和8.82%。蒙古沙冬青的光合作用主要受非气孔限制影响,包括光反应的原初电子捕获效率、电子传递功能、暗反应的Rubisco酶活性和RUBP再生受到抑制,导致其光合作用降低。

Ammopiptanthus mongolicus is an evergreen broad-leaved shrub that is distributed in arid desert areas and has a unique adaptation mechanism to arid environment.The results showed that the photosynthetic and water physiological characteristics of A.mongolicus had changed significantly before and after watering.After watering,the daily average values of transpiration rate of the old,middle-aged and young A.mongolicus increased by 29.33%,18.41%and 89.53%,and the daily average photosynthetic rate decreased by 30.06%,24.68%and 8.82%,respectively.The photosynthesis of A.mongolicus is mainly affected by non-stomatal limitation,including the original electron capture efficiency of photoreaction,electron transfer function,the Rubisco enzyme activity of dark reaction and the regeneration of RUBP are inhibited.