沙冬青冬季叶绿体的超微结构特征

沙冬青在冬季的叶肉细胞中有丰富的叶绿体,经常聚集在一起,相互重叠,相互嵌合,有的还相互融合。大部分叶绿体为凸透镜形,多余叶绿体主要为V形、蝶形、连婴形和哑铃形。它们的被膜不光滑,常凹凸不平,甚至出现突起和内陷。类囊体十分发达,质体小球很多,但淀粉粒缺乏。大部分叶绿体形态结构正常,有的还在出芽和分裂。少数叶绿体与此不同,它们已经衰老,其中一些正在解体或已经解体。

ULTRASTRUCTURAL FEATURES IN THE CHLOROPLASTS OF AMMOPIPTANTHUS MONGOLICUS IN THE WINTER PERIOD

In winter chloroplasts are abundant in the mesophyll cells of Ammopiptanthus mangplicus, locate in the cytoplasm anoi-md the central vacuoles and often group together or pile up each other. Sometimes one chloroplast insert into the others through protrusions forming a mosaic pattern, or even two adjacat chloroplasts fuse together. There are various shape in the winter chloroplasts: most of them are convex lense-shaped, others are v-shaped, butterfly-shaped, disomole-shaped and dumbell-shaped. The envelopes of chloroplast are uneven, and usually posses some large protrusions and invaginations, and with s ome vesicular material in the lining matrix. In the chloroplast there are well deve loped thylakoid systems and many plastoglobuli, but starch granules usually are absent, occasionally it may exist in a very small size and only one in chloroplast. Most chloroplasts are normal in morphology, some of them are still in budding and deviding. A few of chloroplasts differ from chloroplasts in morphology mentioned aboved, they are senesced, some even are disintegrating or disintegrated ones.