Microcystis is a freshwater harm algal bloom species,and its taxonomy is difficult to be identified with traditional approach.16S rRNA has been successfully applied to identify this microorganism species.In this study,partial sequences of 16srRNA gene of three strains of M.flos-aquae from 3 reservoirs in Guangdong Province were determined.Clustal1.83 and MEGA3 software package was used to analyze their genetic characteristics.It showed that alignment of the 3 sequences totaled 1035bp without any indels,and nucleotide similarity were above 99.85%,which suggested that discrimination of the 3 strains was failed,and 16S rDNA sequences were quite conservative within species.The degree of nucleotide dissimilarity among endemic Microcystis species are yet to be determined.In order to identify Microcystis species from reservoirs in Guangdong Province,more strains of various morphology and origins should be analyzed to build nucleotide database of sequences of 16s rRNA and other gene,so that difference within and among species could be found and species-specific probes could be designed.
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