Federal Rural de Pernambuco; Recife- PE- Brasil

The escalating occurrence of cyanobacterial toxic blooms demands a better understanding of genetic variability as an auxiliary expedient in species identification, collaborating with the monitoring of water destined to public supply. This study aimed at the unraveling of genetic polymorphism in the toxic and nontoxic strains of Microcystis (Cyanobacteria) species, isolated from diverse Brazilian localities through the RFLP-PCR technique applied to the c-phycocyanin encoding operon and its intergenic spacer (cpcBA-IGS). Eighteen strains belonging to M. aeruginosa, M. panniformis, M. protocystis and M. wesenbergii, plus two other unidentified strains, were analyzed by means of the morphological and molecular data. The molecular data constituted three groups with low similarity values unrelated to the geographical origin, toxicity or morphospecies. A high genetic variability among the studied populations was unveiled by the results. Brazilian populations of Microcystis spp. displayed high genetic diversit