Different levelsof genomic significance were used in assisted selection by markers to estimatethe phenotypic value, the number of markers used in the selection and the percentageof favorable and unfavorable alleles fixed in a quantitative characteristic.A comparison among the levels 0.5; 1; 2; 4; 6; 8; 10; 12; 14; 16; 18 and 20was done by using the computer system of gene simulation (GENESYS), used forsimulation of a genome consisted of a quantitative character with heritabilityequal to 0.20. From the initial population, the evaluation of the twelve levelsof significance by selection assisted by markers was carried out using the phenotypicvalues obtained for 10 generations. The cluster method by composite link wasapplied by using the average Euclidean distance as dissimilarity measure amongthe genomic significances. There are similarities among the phenotypic valuesobtained with significance levels from 4 to 16%, which are superior to the highlysignificant (from 0.5 to 2%) and to the extremely suggestive levels (18 and20%), because of the phenotypic gains obtained over generations under selections.
