Genetic parameters and selection indexes in F2 and F2:3 soybean populations

The evaluation of genetic parameters in early generations select individuals in F2 and F2:3 and advancing only progenies with the potential to generate pure productive lines. The objectives of this study were to estimate genetic and phenotypic parameters in F2 and F2:3 populations derived from UFUS 7415 and TMG 7161 RR, evaluate different genotype selection strategies, and select progenies to improve agronomic traits. Populations in the F2 and F2:3 generations derived from a biparental cross between the parents UFUS 7415 and TMG 7161 RR were evaluated. The genetic parameters of 360 individuals in the F2 generation and 150 genotypes of each parent were evaluated. Heritability varied from 4.66% for the number of seeds per pod to 86.06% for plant height at flowering. The greatest selection gain was obtained for plant height at flowering (29.68%), related to grain production. In the F2:3 generation, 145 genotypes were evaluated and their parents, in a randomized block design with two replications. The correlations between characters and the genetic gains obtained by direct and indirect selection and based on the genotype–ideotype distance index and the Mulamba and Mock index of the sum of “ranks” were evaluated. With direct selection, selection gains ranged from –5.34 to 16.19%. The genotype–ideotype distance index showed a total selection gain of 40.49%, while the Mulamba and Mock index of the sum of ranks obtained a total gain of 39.35%. Twenty‐three genotypes were selected for the characters evaluated with both indexes in the F3 generation. Core Ideas The genetics parameters they are estimated based on coefficients such as heritability. Correlation between two characters allows for measuring the extent of association between them. Selection indexes allow for the simultaneous selection of a group of characters.