Endogamy and genetic variability in selective mating using distribution of extremes

Abstract

-The objective of this study was to evaluate selective mating using distribution of extremes, among other mating strategies, on its ability to decrease the endogamy and the loss of genetic variability. The genetic simulation system (Genesys) was used to simulate two genomes (each one with a single characteristic whose distinction was the value of heritability) and the base and original populations. Each initial population was submitted to assisted selection by markers for ten consecutive generations. For evaluation of strategies, the estimated parameters were phenotypic value, endogamy and additive genetic variance, in different family sizes, for both characteristics. In all scenarios combining heritability and family sizes, the selective mating was superior to the others, in the ability to decrease endogamy and maintain higher magnitudes of genetic variability.Consequently, superior phenotypic increments were obtained, pointing to a major detection of quantitative trait loci in the assisted selection by markers due to gradual decrease of the additive genetic variance over the generations.