Diversidede genética de ostras do genero Crassostrea na Resex Marinha da Baia do Iguape - Ba, por meio de marcadores ISSR

Abstract

Crassostrea sp are bivalve molluscs that inhabit the estuarine and brackish waters These animals are of great importance to the riverine communities that through extractivism complement the income of these families, representing an important social role since the activity is usually carried out by autonomous workers (mostly women) or organized in associations and cooperatives that live in capture and processing of shellfish. This work aims to characterize, through ISSR molecular markers, the species Crassostrea sp collected from submerged environments and mangrove roots in order to obtain a better knowledge of the genetic diversity within and among the populations of oysters collected in the region of Capanema, trying to identify the possibility of occurrence of different species of the genus Crassostrea in the points sampled. The 90 specimens sampled were taken alive for analysis at the Laboratory of Genetics of Aquatic Organisms (LAGOA), at the Federal University of Recôncavo da Bahia (UFRB). These data include a set of information for the conservation of the species and maintenance of commercial fishing activity in the Capanema-Bahia region. The procedures for the extractions of the total DNA were carried out using the biological material of the adductor muscle of each individual, through the protocol of extraction of Phenol: Chloroform, and then analysis with molecular markers. A total of 6 ISSR primers were used. It was possible to affirm that primers type ISSR, were competent to detect a high genetic variability intrapopulacional and high genetic structuration. With the results of high genetic identity (0.9456) and low genetic distance (0.0560) between the two oyster populations studied, the mean genetic diversity of Nei (H) was 0.727 (σ ± 0, 18) for the individuals collected in the mangrove roots and 0.2154 (σ ± 0.17) for the submersed. The possibility of being populations composed of different species has not been identified. The analysis of molecular variance showed that 75.70% of the total variation is within the studied populations and 24.30% among the populations. We found an FST value of 0.243, presenting a high genetic structure. We indicated a gene sequencing for the final confirmation of the species analyzed in this study. Thus, oysters collected from the rocks (submerged) or mangrove roots in the community of Capanema showed high genetic variability, offering the possibility of being used in conservation and breeding programs.