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

作为水华形成蓝藻微囊藻分子分类修订的一部分，对日本微囊藻的等位酶差异进行了研究，特别是对其形态和毒性进行了研究。对采自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四个酶座位的等位酶基因分型，(2)平均细胞大小和菌落形态特征分析，(3)三种微囊藻毒素(-RR、-YR、-LR)的毒素组成分析。根据等位酶基因的统计分析，微囊藻属至少由以下5个分类实体组成。这五个分类实体的形态和生化属性概括如下。(1)铜绿假单胞菌S1型：细胞大小，菌落不具特征，无毒。(2)铜绿假单胞菌S2型：细胞大，菌落不具特征，有毒。(3)L型：细胞大，笼状菌落，剧毒。(4)绿色微囊藻：细胞大，立方菌落，有毒。(5)韦森伯吉尔微囊藻：细胞大，菌落无特征，无毒。这些成果将为微囊藻属提供一种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.