MELHORAMENTO GENÉTICO DAS CULTIVARES DE MILHO CMS 47 E BR 5039 (SÃO VICENTE) NA REGIÃO MEIO-NORTE DO BRASIL

In the agricultural year of 2000/2001 the corn varieties CMS 47 sintetic and the BR 5039 were submitted to one cycle of half-sib family selection in the Brazilian MidNorth Region, to elevate the favorable alleles frequency and to obtain estimates of the genetic and phenotypic parameters. In the same agricultural year, for obtaining one cycle by year, 196 families were evaluated in a 14 x 14 simple lattice experimental design, with recombination of the selected families. For ear weight, the CMS 47 sintetic variety had higher variability than the BR 5039, contemplated with a larger component of the additive genetic variance. The expected genetic gain with the half-sib family selection also expressed that variability, being 5.63% for the CMS 47 and 0.72%, for the BR 5039. The magnitude of the family x environment interaction points out the importance of evaluating the families in more than one location, to improve the efficiency of the selective process and to obtain more consistent estimates of the variance components.