Genetic diversity in two species of freshwater cyanobacteria, Planktothrix (Oscillatoria) rubescens and P. agardhii
Humbert, J. F.; Le Berre, B.
published: Jan 11, 2001
ArtNo. ESP141015002002, Price: 29.00 €
The genetic diversity of two freshwater cyanobacteria, Planktothrix rubescens and P. agardhii, was studied by sequencing a 519bp fragment of the 16S rRNA gene, a 550 bp fragment of the psaAB locus, a 517bp fragment of the rbcLX locus and a 550bp fragment of the 16S-23S ITS. Most of the 19 isolates were obtained from five alpine lakes, except for four purchased from culture collections. There was no polymorphism between the P. rubescens/agardhii strains for the 16S rRNA gene (partial sequencing) and only a few polymorphic sites were found in the other sequences. These informative sites had a mosaic structure in the Planktothrix strains, suggesting the occurrence of recombination between them. In contrast, the population structure during a bloom appears to be clonal. The existence of recombinations between the strains of P. rubescens and P. agardhii and the 16S sequencing data suggest that they are conspecific.