水分胁迫对果梅光合色素和光合作用的影响

Effects of water stress on photosynthetic pigment and photosynthesis in leaves of Japanese apricot

比较了 2个果梅品种青皮梅和龙眼梅经不同程度水分胁迫处理后叶片光合色素和光合作用的变化 .结果表明 :中度水分胁迫下 ,光合速率 (Pn)、气孔导度 (Gs)和胞间 CO2 的体积分数均下降 ,叶绿素 (Chl)和类胡萝卜素 (Car)下降不显著 ,光合作用受抑制主要是因为气孔限制 ;严重水分胁迫下 ,Pn和 Gs下降得更低 ,Chl和 Car下降显著 。

The changes of photosynthetic pigment content and photosynthesis in the leaves of two cultivars of Japanese apricot (Prunus mume Sieb. et Zucc.), drought resistant Qingpimei and drought sensitive Longyanmei, were compared under medium and severe water stress. Under medium water stress, net photosynthetic rate (Pn), stomatal conductance (Gs) and the volume fraction of intercellular CO 2 decreased, meanwhile, the decrease of chlorophyll (Chl) and carotenoid (Car) coutents was insignificant, so it was proved that the decline in photosynthesis was due to the decline in Gs. Under severe water stress, Pn and Gs dropped down to a lower level, and Chl and Car contents also decreased significantly, therefore, it was suggested that non stomatal factors were the major causes of the decline in photosynthesis.