Parental selection based on molecular information under a population genetics approach

Abstract

The correct choice of parents that will compose optimal segregating populations is the key to success for breeding programs. It was postulated the hypothesis that this choice of these parents could be made based on information of molecular markers analyzed in the context of population structure. Ten parental populations were simulated and 45 hybrid combinations were obtained from the dialel crosses. Each population consisted of 200 individuals with 50 independent loci. The populations were evaluated for the Hardy-Weinberg Equilibrium (HWE), Coefficient of Inbreeding (F), Heterozygosity (H), and the Polymorphic Information Content (PIC). Genetic diversity between pairs of parental populations was evaluated using five dissimilarity measures. Values of Mantel correlation were obtained for the pairs of the dissimilarity matrices, and the PIC, H, and F values ​​were obtained in the hybrid combinations. All parental populations were under HWE, and the combination that emerged from this condition was the hybrid 3x5, with only 26% of the loci manifesting HWE. This same hybrid was among those with lower F estimates and higher values ​​of H, which indicated the existence of greater divergence between their parentals. There was agreement on the indication of the more and less divergent hybrid combinations for the dissimilarity measures. This fact is important because the variability, associated with the good average potential, are important criteria for the formation of an initial population in breeding programs of any kind, involving sexual processes.