Different levels of genomic significance were used in the selection assisted by molecular markers to estimate the medium endogamy and the selection limit, as well as the phenotypic value, for quantitative traits of low, medium, and high heritability. A comparison among the levels of genomic significance of 1%, 5%, 10%, and 20% was accomplished by a computer system of genetic simulation (GENESYS), used to simulate three genomes, each of them constituted by only one character of low, medium and high heritability, and to simulate the base and the initial populations. The results suggest superiority of higher significance levels (10% and 20%) for all phenotypic values, as a consequence of lower endogamy, and lower selection limit for low, medium, and high heritability traits, but in more expressive way for low heritability trait. Although the significant levels of 1% and 5% for molecular marker assisted selection showed a high precision in detecting markers related to a quantitative trait loci (QTLs), they lead to higher endogamy and selection limits, resulting in low phenotypic gains.
heritability; significance level; simulation; QTL