冈村枝管藻中性游孢子的发育过程

Development of neutral zoospore in Cladosiphon okamuranus Tokida

本文在国内首次观察描述了冈村枝管藻生活史中由多室孢子囊释放出的中性游孢子的发育变化和各时期的形态特征。成熟的冈村枝管藻孢子体上存在多室孢子囊，由多室孢子囊释放出的中性游孢子附着后直接萌发为盘状体，1周左右盘状体的周边长出许多同化丝和无色毛丝体，在同化丝逐渐成熟的过程中伴随着毛丝体的脱落或萎缩死亡，盘状体即发育成孢子体。通过人为控制条件，在室内对多室孢子囊枝进行连续数月的培养和观察，发现由中性游孢子发育而来的孢子体长到1～2mm即成熟，在同化丝顶部形成多室孢子囊进入下一轮循环。由多室孢子囊释放出的中性游孢子是人工育苗生产过程中苗种的主要来源。

In this paper, the authors observed and reported the morphological characters and development process of neutral zoospore derived from plurilocular sporangium of Cladosiphon okamuranus for the first time in China. The mature sporophytes of Cladosiphon okamuranus produced plurilocular sporangium, zoospores from plurilocular sporangium developed into discoidal germlings after attachment, then the germlings formed many achromatous hairs and erect assimilatory filaments in about one week, the hairs would break off or perish during the process of mature germlings. The discoidal germlings derived newly formed plurilocular sporangium and developed into the thalli of sporophyte. Under artificial controll conditions, the mature germlings were cultured in the laboratory for several months, the result showed that the germlings developed from zoospores were mostly mature in the length of 1 -2mm,and the plurilocular sporangia of zoospores formed in the top of assimilatory filaments entered into a repeated generations of discoid development, but unilocular sporangium were not been seen in the mature thalli of sporophyte. Zoospores are the main source of seedlings for artificial seeding of Cladosiphon okamuranus.