黄化西瓜叶片叶绿体结构与光合作用特性

Chloroplast Structure and Photosynthesis Characteristics of Leaves in the Chlorophyll-deficient Watermelon Plant

对黄化西瓜的黄化性状表现及叶绿素含量、光合速率等指标的测定和叶绿体超显微结构进行了观察,结果表明,黄化西瓜叶绿素含量低,相当于绿叶西瓜中育1号(CK)的55%;叶绿体的发育明显差于对照品种,表现为基粒窄、片层数少、基粒在叶绿体中分布稀疏;黄化西瓜光合速率较低,仅为CK的73.5%～75.8%,地上部全生物量为CK的76%,对光合作用测定相关参数的分析认为黄化西瓜叶绿素含量低是光合速率低的惟一原因;黄化西瓜的光补偿点高达157μmol/m2·s,表明尽管其单位叶面积光合速率较低,但消耗仍然维持了相当的水平。

A comparative study of the watermelon plant char ac teristics,leaf chlorophyll content ,photosynthesis,biomass and electron micro scopic image of chloroplasts were carried out between a chlorophyll-deficient variety(CD)and normal green type“Zhongyu-1”(NG).Results indicated that chlorophyll content of CD was only55%corresponding to that of NG,the devel opment of grana stacks in chloroplasts was relatively poor,the lamellaes were shorter and fewer,and there were fewer grana stacks in the chloroplasts.Theref ore,leaves of CD had a lower net photosynthesis rate(Pn).It was73.5%～ 75.8%of NG.Biomass above ground of CD plant was76%of NG.Because of hi gher Gs and Ci ,so a lower Pn and biomass of CD were caused by lower chlorophyl l content.The Light compensation point of CD was157ìmol/m 2 ·s higher than that of NG.It means that the consumption in leaf of CD is a t normal level.