干旱胁迫对红叶石楠叶片光合生理特性的影响

Effects of Drought Stress on Photosynthetic Characteristics of Photinia frasery Dress

对不同程度干旱胁迫下红叶石楠的叶片膜伤害和光合生理特性进行了研究。结果表明,随着干旱程度的增加,叶片含水量、光合色素含量以及净光合速率等生理指标都有不同程度的下降,而花青素含量、丙二醛含量和细胞膜透性大幅增加。在轻度干旱下,净光合速率、气孔导度和胞间CO2浓度同步下降,光合受抑的主要限制因子为气孔因素;中度、重度干旱胁迫下,净光合速率、气孔导度下降的同时,胞间CO2浓度上升,此时光合受抑的主要限制因子为非气孔因素。

Effects of drought stress on the membrane injury and photosynthetic characteristics in the leaves of Photiniafrasery Dress were studied. The results showed the relative water content, chlorophyll and carotonoid contents and net photosynthetic rate （Pn） in leaves of Photinia frasery decreased with aggravation of drought stress, while the content of anthocyanin, Malondialdehyde and the membrane permeability inhanced significantly. Under light drought stress, Pn, stomatal conductance （Gs） and intercellular CO2 concentration （Ci） decreased at the same time, so the photosynthetic inhibition was due to stomatal limitation. Under moderate and severe drought stress, Ci increased with decrease of Pn and Gs, indicating the photosynthetic inhibition resulted from non-stomatal limatation.