水分胁迫下外源甜菜碱对桃叶片光合作用的影响

笔者研究了水分胁迫下叶面喷施甜菜碱对桃叶片光合作用的影响。结果表明,水分胁迫前期光合速率下降与气孔因素有关,后期光合速率下降与非气孔因素有关。对桃叶片喷施一定浓度的外源甜菜碱可以提高胁迫前期的净光合速率;这可能与甜菜碱处理提高SOD的活性,保持较低的超氧阴离子自由基生成速率和MDA含量,减轻干旱对树体伤害有关。

The Effects of Exogenous Betaine on Photosynthesis of Peach Leaves under Water Stress

The effects of exogenous Betaine on photosynthesis of peach leaves was investigated under water stress . The results showed that the stomatal limitation was the main factor of the decline of Pn in the early period of stress , and the nonstomatal limitation was the main factor of the decline of Pn in the late period of stress. Moreover, Pn of the peach leaves in the early period of stress was increased by spraying betaine in the leaves, which was probably related to the following reasons that SOD activity was increased , O~·_2 generation rate and content of MDA were reduced, and the hurt of water stress was decreased by spraying betaine in the leaves.