Selection indices for agronomic and chemical traits in segregating populations of sweet corn

In the sweet corn breeding, the selection of superior genotypes should consider many traits simultaneously. The best strategy to select traits simultaneously is through selection indices. This study aimed to verify traits that have direct effect about grain yield (GY) in order to compose the selection indices and to compare these indices on sweet corn populations. Eighteen traits were evaluated in eight genotypes of sweet corn belonging to generation F3. The data were submitted to analyses of variance and path coefficient analyses. We compared the direct and indirect selection and the following indexes: base, classical, desired gain and genotype-ideotype distance. According to path coefficient analyses, the traits which showed a direct effect about GY were stand, number of ears, ear diameter, number of grains per row and industrial yield, which composed the indices. The base index provided the greatest total genetic gain, desired gains on all traits, uniform distribution of the gains and considerable gains on GY.