Genotypic Selection for Soybean Earliness

Obtaining early-maturing soybean cultivars with high yield performance has long been the focus of breeding programs. Obtaining the estimates of genetic and phenotypic parameters can assist breeders at selecting the superior genotypes. Therefore, the aim was to estimate the genetic and phenotypic parameters of progenies throughout the recurrent selection for early maturity in soybeans and to select progenies with superior agronomic traits. S0-1 progenies were evaluated in one site during the 2015/2016 harvest using a 12 × 12 lattice design, with one 2-meter row plot with two replicates. The S0-2 progenies were evaluated during the 2016/2017 harvest using an 8 × 8 lattice design, with one 3-meter row plot with three replicates. The S0-3 progenies were evaluated during the 2017/2018 harvest using a 5 × 5 lattice design, with two 3-meter rows plots with three replicates. Both S0-2 and S0-3 progenies were evaluated in three different sites. The days to flowering, full maturity, first pod insertion height, plant height, lodging index and grain yield traits was evaluated. The data were analyzed using a mixed model approach. The genetic and phenotypic parameters, expected gain with selection, realized heritability, correlated response and the frequency distributions of the adjusted means were estimated. The estimates of the variance components have evidenced variability among the progenies, enabling the selection of superior genotypes. All the evaluated progenies showed good agronomic performance, combining early maturity and productive performance. When early-maturing progenies were selected, there was a reduction in days to flowering, plant height, first pod insertion height, lodging and yield.