Caracterização genética de diferentes gerações do Programa de Melhoramento Genético de Tilápia da Universidade Estadual de Maringá

Abstract

The objective was to evaluate the genetic variability of the founder (G0) and subsequent three generations of GIFT strain (G1, G2, G3) belonging to a breeding program UEM-CODAPAR. We evaluated 90 individuals per generation, using microsatellite molecular markers. The five microsatellite loci used showed a total of 21 alleles, present in all generations, with the presence of low frequency alleles and null alleles of the loci and UNH140 UNH163. The genetic variability was similar in all generations, and the G1 had the lowest average observed heterozygosity (Ho = 0.391) possibly forming the number of families of this generation. The average observed and expected heterozygosity (He), the deviation in Hardy-Weinberg equilibrium (HWE) and the presence of linkage disequilibrium in some loci showed an excess of homozygotes, since the rate of inbreeding was 0.192 between the values in G0 and 0.401 in G1. In effect test "Bottleneck" all loci showed disequilibrium. Results reflect the planning and development of the breeding program that is implemented in GIFT tilapia in Brazil, the first four generations have maintained genetic variability.