DIVERSITY OF THE VALVE ONTOGENY IN DIATOMS AND ITS RELATIONSHIP TO THE PHYLOGENY

从日本各地收集了海洋和淡水硅藻。将其分离培养，作为形态学观察和分子实验材料。成熟阀门的扫描电镜观察发现了一些新的结构。在球果中，副孢子形成的球阀和正在发育的周状体。在发育的中期，叶藻的瓣体发育与冠状蝶藻有一定的相似性。但在后期表现出与双蚜硅藻的个体发育相似性。将荧光标记剂引入形成瓣膜中，可以区分核酸分裂后新形成的瓣膜和核酸分裂前已形成的瓣膜。18S rDNA分析新确定了Pseudostaurosira、Pseudohimantidium、Berkeleya、Diploneis、Luticola、3个圆柱目和Nitzschia palea的系统发育位置。在系统发育树中，由于Pseudohimantidium与其他海麒麒亚属形成了单系关系，因此在形态学上指出了pseudohimanidium与Eunotia之间的密切关系。除了硅藻科与硅藻科的亲缘关系（根据OUT的数量和系统发育分析的方法，这是一种机会主义关系）外，硅藻类群的高阶分支顺序反映了该类群早期到中期的个体发育相似性。在5种硅藻中测定的Sill-like DNA序列显示出高度的相似性，暗示其可能成为探索生物硅矿化能力起源的探针。

Marine and freshwater diatoms were collected from various places in Japan. They were isolated and cultured for the materials of morphological observations and molecular experiments. SEM observations of mature valves revealed some new structures in several species. In Cocconeis the forming valves and the developing perizonium of auxospore. The valve ontogeny of Eunotiashowed some similarity to araphid pennate diatoms in the middle stage of the development. But it showed ontogenetic similarity to biraphid diatoms in the late stages. Use of a fluorescent-label agent, which was taken into the forming valve, could distinguished the newly formed valves after nucleic division and valves already formed before nucleic division. The analyzes of 18S rDNA newly showed the phylogenetic position of Pseudostaurosira, Pseudohimantidium, Berkeleya, Diploneis, Luticola, three Cylindrofheca specis and Nitzschia palea. Close relationship between Pseudohimanthidium and Eunotia, that had been pointed out based on morphology, was not shown in the phylogenetic trees, as Pseudohimantidium formed monophyly with other araphid marine genera. Except for the relationship between Bacillariaceae and Eunotiaceae, which is an opportunist according to the number of OUT and the methods of phylogenetic analyzes, the branching order of the higher rank of diatom taxa reflected that of the ontogenetic similarities from the early to middle stages of the taxa. Sill-like DNA sequences decided in five diatoms showed the high similarity among them, impling its possibility to become a probe for exploring the origin of the biosilica mineralization ability.