Molecular Taxonomic Study of Microcystis (Cyanophyceae) Based on Allozyme Divergence.

作为水华蓝绿微囊藻分子分类学研究的一部分，对日本产的微囊藻进行了形态学和毒性方面的研究。对采集自23个湖泊、池塘和水库的78株微囊藻毒素（-RR、-YR、-LR）进行了IDH、6PGD、PGI和PGM 4个酶位点的等位酶基因型分析、平均细胞大小和菌落形态特征分析以及毒素组成分析。等位酶基因型的统计分析结果表明，微囊藻属至少由以下五个分类实体组成。五个分类实体的形态和生化属性总结如下。(1)M.铜绿假单胞菌S1型：细胞大小小，菌落无特征，无毒。(2)M.铜绿假单胞菌S2型：细胞体积小，菌落无特征，毒性强。(3)M.铜绿L型：细胞大小大，笼形菌落，毒性强。(4)M.绿色：细胞大小大，立方形菌落，有毒。(5)M.韦森贝吉尔：这些研究成果将为微囊藻属的分类系统和鉴定（包括毒性预测）提供新的方法。

As a part of molecular taxonomic revision of the bloom-forming blue-green alga Microcystis, allozyme divergence of the Japanese strains of Microcystis were studied with special reference to their morphology and toxicity. We analyzed (1) allozyme genotype at four enzyme loci, IDH, 6PGD, PGI and PGM, (2) average cell size and characteristics of colony morphology and (3) toxin composition of three microcystins (-RR, -YR, -LR), using a total of 78 strains collected from twenty-three lakes, ponds and reservoirs. As a result of statistical analyses of allozyme genotype, it was elucidated that the genus Microcystis consists of at least five taxonomic entities listed below. Morphological and biochemical attributes of the five taxonomic entities are summarized as follows.(1) M. aeruginosa S1-type : cell size small, colony not characteristic, untoxic.(2) M. aeruginosa S2-type : cell size small, colony not characteristic, toxic.(3) M. aeruginosa L-type : cell size large, clathrate colony, highly toxic.(4) M. viridis : cell size large, cubic colony, toxic.(5) M. wesenbergil : cell size large, pouched colony, nontoxic.These achievements will provide a new taxonomic system and identification method (including forecast of toxicity) of the genus Microcystis.