杨品种‘84K’光合生理的不同过程对干旱和复水的响应

以杨品种‘84K’（Populus alba×P.glandulosa）为材料，对其干旱胁迫及复水后光合生理特性的变化进行了研究。结果显示，在干旱胁迫及复水过程中，杨品种‘84K’光合作用相关的主要反应对此过程响应不同步。在干旱胁迫过程中，‘84K’的羧化反应速度、气孔导度（G_s）、叶肉导度（G_m）均显著下降，但前者下降幅度小于后两者，此时的光合作用主要受G_s和G_m制约。复水之后，G_m很快得到恢复，而光化学淬灭过程、羧化反应速度均没有恢复到对照水平，此时是光化学淬灭和（或）羧化反应制约了‘84K’的碳固定及光合作用。

Responses of different photosynthetic physiological processes in Populus alba×P. glandulosa to drought and rehydration

Populus alba×P. glandulosa (‘84K’) was used to study changes in photosynthetic physiological characteristics after drought stress and rehydration. Results showed that the main photosynthetic processes of ‘84K’ were not synchronous during drought stress and rehydration. During drought, the carboxylation rate, stomatal conductance (G_s), and mesophyll conductance (G_m) of ‘84K’ declined significantly, but the former decreased less than the latter two. Thus, at this time, photosynthesis was mainly restricted by G_s and G_m. After rehydration, G_m recovered rapidly; however, the photochemical quenching process and carboxylation rate did not recover to the control level, which may restrict the carbon fixation and photosynthesis of ‘84K’.