Microcystis aeruginosa was quantitatively surveyed in 88 freshwater environments across Japan within 3 weeks in 2011. In order to clarify the distribution pattern of M. aeruginosa at the intra-species level, three major genotypes, which were defined by 16S–23S rRNA inter-transcribed-spacer (ITS) regions, were selectively detected using quantitative real-time PCR assays. Of the 68 sites at which the Microcystis intergenic-spacer region of the phycocyanin (IGS-PC) gene was detected, the M. aeruginosa morphotype-related genotype (MG1) dominated in 41 sites, followed by the non-toxic M. wesenbergii-related genotype (MG3). A correlation analysis showed that total nitrogen and phosphate positively correlated with the abundance of IGS-PC, which positively correlated with microcystin synthetase gene abundance. A redundancy analysis of genotype compositions showed that pH positively correlated with the dominance of MG3 and negatively correlated with MG1, i.e., both toxic and non-toxic genotypes. Our survey of Microcystis populations over a wide area revealed that MG1 is a dominant genotype in Japan.

中文翻译：

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日本88个淡水环境中有害花芽蓝细菌Microcystis aeruginosa的分布

2011年3周内对日本88个淡水环境中的铜绿微囊藻进行了定量调查。 为了阐明铜绿假单胞菌在种内水平的分布格局，3个主要基因型由16S-23S rRNA互转录定义-间隔（ITS）区域，使用定量实时PCR检测选择性地检测。在检测到藻蓝蛋白 (IGS-PC) 基因的微囊藻基因间间隔区的 68 个位点中，铜绿假单胞菌形态型相关基因型 (MG1) 在 41 个位点占主导地位，其次是无毒的 M. wesenbergii-相关基因型 (MG3)。相关性分析表明，总氮和总磷与IGS-PC丰度呈正相关，而IGS-PC与微囊藻毒素合成酶基因丰度呈正相关。基因型组成的冗余分析表明，pH 与 MG3 的优势呈正相关，与 MG1 呈负相关，即有毒和无毒基因型。我们对大面积微囊藻种群的调查显示 MG1 是日本的优势基因型。