Fixing of alleles and increment the phenotypic level selection assisted by markers using different mating strategies

Abstract

The objective of this work was to evaluate the selective mating using distribution of extremes, among other mating strategies, in its ability to benefit favorable setting alleles and delaying the unfavorable seting alleles, as well as optimize the phenotypic level feature under assisted selection by markers. The genetic simulation system (Genesys) was used to simulate of two genomes (each consisting of a single characteristic with heritability 0,10 and 0,40), and the base and original populations. Each initial population was submitted to assisted selection by markers for ten consecutive generations. For evaluation of mating strategies were estimated averages of the values as a percentage of earnings by fixing favorable alleles, percentage values of losses by setting unfavorable alleles and phenotypic values, in different family sizes, for the two characteristics. In all scenarios that used a combination heritability and family sizes, the selective mating was superior to others, having the ability to increase the setting of favorable alleles and delaying the unfavorable seting alleles. Consequently, phenotypic increments above were obtained. This fact signals major detection of quantitative trait loci in the assisted selection by markers for admiting selective mating, due to gradual decrease of genetic variability over the generations as a result of lower characteristics unfavorable alleles.