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

作为形成华花的蓝绿藻微囊藻的分子分类修订的一部分，对微囊藻日本菌株的等位酶分化进行了研究，特别参考了它们的形态和毒性。我们分析了(1)在IDH、6PGD、PGI和PGM 4个酶位点上的等位酶基因型；(2)平均细胞大小和集落形态特征；(3)从23个湖泊、池塘和水库采集的78株微囊藻毒素（-RR、-YR、-LR）的毒素组成。等位酶基因型统计分析结果表明，微囊藻属至少包含以下5个分类实体。5个分类实体的形态和生化特征总结如下。(1)绿脓杆菌s1型：细胞大小小，菌落无特征性，无毒。(2)铜绿假单胞菌s2型：细胞大小小，菌落无特征性，有毒性。(3)铜绿假单胞菌l型：细胞大小大，笼形菌落，剧毒。(4)病毒分枝杆菌：细胞大小大，立方集落，有毒。(5)微孢子虫：细胞大，囊状菌落，无毒。这些成果将为微囊藻属提供新的分类体系和鉴定方法（包括毒性预测）。

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.