Genetic Variability of some Tilapia Species from three different Reservoirs in Southwestern Nigeria

Сажетак

The technique of random amplified polymorphic DNA (RAPD) marker has been used for stock identification and discreteness and population analysis in fish but the potential for species and stock characterization has not yet been fully established for tilapias in Nigeria. A study on the genetic similarity within and between three species of tilapia (Sarotherodon galilieaus, Tilapia guineensis,andOreochromis niloticus) was carried outto identify novel traits for the improvement of breeding techniques and production in aquaculture.One hundred and eighty-fivetilapias were collected from three reservoirs: Owena, Asejire, and Aibain Southwestern Nigeria.RAPD primers were used to estimate the genetic variation and their phylogenetic relationships. A total of thirty-five RAPD primers were screened for this study out of which, twelve RAPD markers gave reproducible bands and four primers yielded a clear and consistent DNA banding pattern.Seventy-seven detected alleles were generated by the twelve RAPD primers consisting of thirty-two alleles as monomorphic and forty-five as polymorphic. UPGMA cluster analysis of genetic data showed a high level of genetic similarity and produced two main clusters: CI andCIIat 59.8% similarity level. Cluster I had twenty-four samples and Cluster II had eleven samples. The result of this study on the genetic similarity of fish and its genome is vital for improved fish breeding techniques.