Genetic variability in Pseudoplatystoma reticulatum from a breedingprogram in Brazil

Resumo

The aim of this study was to characterise genetic variability in five groups of Pseudoplatystoma reticulatum:
Mato Grosso I (MT-I), Mato Grosso II (MT-II), Mato Grosso III (MT-III), Mato Grosso do Sul I (MS-I) and Mato Grosso do Sul
II (MS-II), taken from a centre for genetic improvement. In order to determine the allelic frequency, observed heterozygosity
(HO
), inbreeding coefficients (FIS), Hardy-Weinberg equilibrium (HW
-p) and genetic differentiation, eight polymorphic
microsatellite loci (Pcor01, Pcor05, Pcor08, Pcor10, Ppu01, Ppu04, Ppu09 and Ppu10) were selected, in which a total of 62
alleles were observed in the individuals (n = 211). The MS-I population had the highest (Pcor08 allele 83: 0.5000) and lowest
(Pcor10 allele 50: 0.1667) mean values for allele frequency. Higher (HO = 0.782; 0.782) and lower (FIS = 0.034; 0.061) values
were found in groups MS-I and MT-III respectively. The HW
-p showed that the five groups presented deviations for most of
the loci under analysis. Finally, genetic differentiation pointed to the formation of two large genetic groups, one formed by the
groups from Mato Grosso and the other by the groups from Mato Grosso do Sul. These measurements can help selection in a
breeding program and maintain genetic variability.