水仙生长过程中叶片光合性能与叶绿体超微结构的变化

试验测定了水仙抽莘、开花、凋花、花后4个时期叶片光合速率、蒸腾速率、叶绿素和蛋白质含量等,并观察了叶片叶绿体超微结构的变化。结果表明,随水仙的生长发育,其叶片含水量、气孔导度明显降低,净光合速率、暗呼吸速率及光合／呼吸比值迅速下降,蒸腾速率和水分利用率也随之降低,叶绿素含量显著上升,叶绿素a/(?)b比值缓慢降低,可溶性蛋白质含量也呈下降趋势。电镜观察显示叶片叶绿体超微结构在抽莘期基粒、基质片层结构发达而清晰,开花期则膨胀松散,凋花期表现萎缩,而在花后生长期片层结构解体。

Changes of photosynthetic efficiency and chloroplast ultrastructure of narcissus leaf blades in different development stages

At four development stages of narcissus,i. e. narcissus-bolting stage,flowering stage,blossom fall stage and post floral stage,some physiological and biochemical characteristics of leaf blades,such as photosynthetic rate, transpiration rate, contents of chlorophyll and protein were measured and the change course of the chloroplast ultrastructure was observed. With the development of narcissus, the water content and stomata conductance decrease significantly, the net photosynthetic rate,the respiratory rate and the ratio of photosynthetic rate to respiratory rate also decrease obviously, whereas the content of chlorophyll rises obviously, the value of chlorophyll a/b reduces tardily and the content of soluble protein presents a decreased tendency. Furthermore,the electron microscope observation shows that the ultrastructures of chloroplast grana and grana lamella are developed and clear at bolting stage,inflated and loose at flowering stage,withered at blossom fall stage and disaggregated at post floral stage.