冈村枝管藻孢子体的形态和超微结构

Morphology and Ultrastructure of Sporophyte of Cladosiphon okamuranus,Tokida(Chordariaceae,Phaeophyta)

从日本冲绳采回枝管藻,用毛细管将成熟多室孢子囊挑出,在试验室条件下培养,可长成孢子体.用光学显微镜和透射电子显微镜观察发现:孢子释放后形成盘状体附着在基质上,念珠状同化丝从盘状体中间分生.同化丝可从中间部位产生分支,多室孢子囊位于部分同化丝的近端部;同化丝大量产生后基部细胞平行排列,中空,形成假薄壁组织,而后孢子体进入伸长生长阶段;在每个盘状体细胞和同化丝细胞中都有多个色素体和线粒体,蛋白核突出于色素体其他部分,类脂体存在于类囊体中;在同化丝的细胞壁上存在缺口;对同化纤毛而言,色素体和线粒体数量少,紧贴细胞膜,质壁分离严重,在细胞壁上存在"通道".

Mature plurilocular sporangia of Cladosiphon okamuranus, Tokida were collected from their natural habitats in Okinawa Island, Japan, and cultured under laboratory conditions. Light and transmission electron microscopy were employed in studying the structure and ultrastructure of sporophytes. Germlings of sporophyte are developed from discoids. Assimilatory filaments aroused from discoids are miniliform, comprising about 15 cells. At the intermediate parts, the assimilatory filaments are found to be branched. Basal cells of many assimilatory filaments are parallel and hollow, and form pseudoparenchyma, when germling turns to elongation growth period. At the apical end of some assimilatory filaments, unguiform plurilocular sporangia engender. Transmission electron micrographs revealed that several chloroplasts and mitochondria exist in each discoid cell and assimilatory filament. Each chloroplast possesses single pyrenoid. Lipid bodies are seen in the chloroplasts. While as to assimilatory hair cells, there are less chloroplasts and mitochondria clinging to plasmalemma. Plasmoloization is apparent with many paths through the cell wall.