锦橙汁囊的超微结构

用常规电镜方法观察了锦橙［Ｃｉｔｒｕｓｓｉｎｅｎｓｉｓ （Ｌ．） Ｏｓｂ．］汁囊从原始细胞到发育为一个具柄的成熟汁囊的过程中，汁囊构成细胞超微结构的变化。锦橙汁囊原始细胞及发育为球状体时的构成细胞以及柱状结构顶端的细胞都是一种典型的分生组织细胞。在细胞质中有包括线粒体、质体、内质网、核糖体等丰富的细胞器，但没有观察到高尔基体。这些分生细胞分裂一段时期后就停止活动，逐渐分化为适应贮藏功能的液泡化薄壁细胞。分生细胞开始分化时，在细胞中出现许多小液泡和高尔基体。这些小液泡逐渐地融合，同时细胞质变少，最后形成一个有中央大液泡的薄壁细胞，在紧贴细胞膜的薄薄的一层细胞质中有线粒体、质体、高尔基体以及含有许多脂滴的杂色体。但成熟果实中汁囊的薄壁细胞中几乎没有任何细胞器。

ULTRASTRUCTURE OF JINCHENG JUICE SAC OF CITRUS SINENSIS

Ultrastructure of Jincheng juice sac of Citrus sinensis (L.) Osb. was continuously investigated from the initial cell to the stalk bearing sac. The initial cell and cells formed globular structure, as well as the uper cells of the column structure were typical meristem cells with mitochondria, plastids, rough endoplasmic reticulum, rich ribosome without Golgi body in their dense cytoplasm. These meristem cells would differentiate into parenchyma cells providing storage function. At the beginning of differentiation of the meristem cells, the number of small vacuoles increased and some Golgi bodies appeared. Small vacuoles gradually fused into a central vacuole. During the fusion of small vacuoles, the cytoplasm became thinned, but still contained mitochondria, plastids, Golgi bodies, endoplasmic reticulum and some chromplasts with lipid drops. Almost no organelle were ever observed in the parenchyma cells of juice sac from mature fruit.