Análise da variabilidade genética em planteis de matrizes de tambaqui (Colossoma macropomum, Cuvier 1818), no estado do Pará, utilizando marcadores microssatélites.

Abstract

The cultivation of fish in the northern region of Brazil has presented a significant development. The species Colossoma mamacropomum is the more cultivated Amazonic species in the region. C. macropomum has been studied for breeding programs in Brazil because it has a closed breeding technology package. One of the major concerns in captive breeding is the genetic determination of the resources variability, qualification of a force that gives the ability to withstand environmental and anthropogenic pressures, especially in farming systems. The determination of genetic variability is important as it can show the genetic relationship between individuals, populations and even between different species. Therefore, the objective of this work is to evaluate the variability of broodstocks of cultivated of matrices in different municipalities of Pará state, using molecular markers of microsatellite type. In the work, 110 matrices of C. macropomum tambaqui were born from four fish farms were analyzed, located in the following municipalities: Peixe- Boi, Santarém, Breu Branco and Ulianópolis. A multiplex panel of tri and tetra nucleotide microsatellites were used for genotyping. Indices of genetic diversity, heterozygosity, number of alleles per locus, and allelic richness, as well as the differentiation population and FST were calculated. The results showed the tambaqui matrices from the four analyzed broodstocks show a significant loss of genetic variability in relation to the natural population, besides being genetically structured in two different stocks.