【摘要】 浮氏鱼腥藻是一种少见的蓝藻门植物,具典型原核植物特征。幼小的浮氏鱼腥藻的藻丝体仅由营养细胞组成,靠营养细胞直接分裂增加细胞数目。在成熟的藻丝体上由营养细胞分化出异形胞和厚壁孢子。营养细胞与异形胞为短圆柱形,厚壁孢子呈椭圆形。在透射电镜下营养细胞具电子浓密的细胞壁、质膜、类囊体和核质区。在核质区内可见到多面体。核区无核膜,被类囊体围绕或分隔并与类囊体连通。营养细胞内有电子浓密的蓝藻颗粒体。异形胞较营养细胞大,有较厚的包被和电子密度低的细胞壁,异形胞两极各有一电子浓密的塞状物,塞状物中见到一不规则的小孔道。异形胞的类囊体扭曲蜿蜒并有点肿胀形成精致的图相,在一个异形胞内还观察到由14层片层围绕着一个电子浓密的具棒状核心的环状膜结构。厚壁孢子的细胞壁厚,细胞内有核质区和精致扭曲的类囊体,细胞中有许多蓝藻颗粒体和极为丰富的核糖蛋白体。更多还原

【Abstract】 Anabaena volzii Lemm. is a rare species of Cyanophyta. It possesses characteristics of prokaryotes. Young filaments of A. volzii consist of only vegetative cells. The filament lengthens by the’increase of its cell number owing to amitosis. A mature filament contains vegetative cells, heterocysts and akinetes; the latter two differentiate from the vegetative cells. Vegetative cells and heterocysts are short-cylindric shaped. An akinete in longitudinal sections of appear to be elliptical. Viewed with a transmission electron microscope, an electron-dense cell wall, plasmolemma, thylakoids (photosynthetic lamellae), nucleo-plasmic region and polyhedral bodies can be seen in the vegetative cell. The nucleo-plasmic region, which lacks a nuclear envelope, is surrounded or dissected, but often connected with the thylakoids. There are also some extremely electron-dense (if samples were post-fixed in osmic acid) cyanophycin granules in its cytoplasm. Heterocyst is larger than vegetative cells. Its remarkable features are a thick envelope, an electron-transparent cell wall and a distinctive plug-like body at both ends of the cell respectively. In the plug-like body is seen an irregular narrow channel. Somewhat dilated thylakoids in the heterocyst appear to be more winding and contorted (than those in vegetative cells), making a dedicate pattern. A long elliptic ring-shaped membrane structure is formed in a heterocyst ,composed,of an electron-dense rod core surrounded by 14 concentric layers of lamellae. Akinete fo(?)ms a thick cell wall. A nucleo-plasmic region, fine and contorted thylakoids, many cyanopl-ycin granules, and abundant ribosomes are found in akinetes.更多还原