Warning of Reducing Genetic Diversity of Abramis brama (Berg, 1905) in Gilan Coast Using SSR Markers

Genetic diversity is one of the three levels of biodiversity. The aim of present study was to compare levels of genetic polymorphism between wild Bream populations using seven microsatellite loci. Genetic diversity wasinvestigated by studying samples collected from two regions, the coast of Chamkhale and Bandaranzali of Gilanprovince. A total of seven microsatellite loci (MFW7, MFW26, Mcs1EH, Rser10, Bl1-153, Bl2-114 and IC654) were used. The average number of alleles in Chamkhale and Bandaranzali coast were 10 and 10.71 alleles, respectively. The numbers of effective alleles were 7.05 and 7.74 alleles in each population. Allele frequency was declined in wild fish due to inbreeding and genetic drift. The mean of observed heterozygosity values were 0.66 and 0.70 inChamkhale and Bandaranzali coast, respectively. Approximately, all of loci showed deviation from Hardy-Weinberg equilibrium. The genetic similarity and distance between the two populations were 0.316 and 0.684, respectively. The results of Molecular Variance Analysis revealed that genetic diversity within locations was 97percent, while among them was 3 percent. The Fst value was 0.024 that indicates the low genetic differentiation between the two locations which could be explained by the low number of alleles in two populations. Furthermore,the Natural Migration (Nm) between two stations was obtained 16.30. According to the analysis, it seems that Abramis brama has not a desirable genetic diversity in the investigated regions