不同发育时期板栗叶肉细胞中叶绿体淀粉和质体小球的变化

Changes of starch grains and plastoglobuli in chloroplasts of mesophyll cells in Chinese chestnut leaf at different stages

对板栗在春季折叠的幼叶和平展生长的幼叶、夏季成熟叶和秋季老叶的叶肉细胞中的叶绿体做了透射电镜观察,结果表明,春季折叠的幼叶的叶绿体中不含淀粉和质体小球,平展生长的幼叶含淀粉粒没有质体小球;夏季成熟叶的叶绿体中淀粉最多并出现极少量质体小球;秋季衰老叶的叶绿体中淀粉粒减少直至消失,质体小球数量激增;有的质体小球在叶绿体内被一层膜包围并降解。根据染色特点,可将质体小球分为黑色和灰色2类。淀粉减少及质体小球增多与叶绿体功能衰退相关。

An observation was made on chloroplasts of the mesophyll cells of the young folded leaves and expanded growing young leaves of Chinese chestnut （Castanea mollissima）in spring,of the mature leaves in summer,and of the aging leaves in autumn by transmission electron microscopy. The results showed that：there were no starch grains and plastoglobuli in chloroplasts of young folded leaves in spring,and there were some starch grains but no plastoglobuli in expanded growing young leaves. There were lots of starch grains but only a few plastoglobuli in chloroplasts of mature leaves in summer. The starch grains reduced and disappeared finally but the plastoglobuli increased significantly in chloroplasts of aging leaves in autumn. Some plastoglobuli were found to be degenerating,and the degeneration happened after they were enveloped by a single-layered membrane. Plastoglobuli could be classified into two groups of dark and grey by their electron density. The deterioration of the chloroplasts should have relationship between the starch grains decreasing and plastoglobuli increasing.