16S rDNA sequences and phylogenetic analyses of Microcystis strains with and without phycoerythrin

Phylogenetic analyses were carried out on 15 strains of Microcystis, with five morphospecies and including two types of phycobilin pigment composition, by sequence determination of the 16S rDNA (16S rRNA gene). All the sequences showed high similarity, in some cases 100% similarity, between different morphospecies and phycobilin types. Derived phylogenetic trees revealed a close relationship between Microcystis strains with and without phycoerythrin. The data show that phenotypes of Microcystis do not necessarily reflect their phylogeny, and that there is a need to reconstruct the present taxonomy at the species level.