CAPACIDADE DE COMBINAÇÃO DE LINHAGENS E SELEÇÃO DE HÍBRIDOS DE MILHO FORRAGEIRO UTILIZANDO ANÁLISE DE COMPONENTES PRINCIPAIS

Abstract

The study aimed to evaluate the agronomic performance of experimental maize hybrids for dual suitability and to use the principal components in the diallel analysis. The hybrids were obtained through a balanced diallel 6x6, resulting in 30 genotypes, there were evaluated in the 2017/18 and 2018/19 crops, with three commercial hybrids as control, in Guarapuava-PR. The characteristics evaluated were male flowering, silage maturity cycle, digestibility in situ, neutral and acid detergent fiber, dry and green mass yield, stay green, grain yield, plant height and ear. The data obtained were subjected to analysis of variance, decomposing the effects of experimental and control hybrids, and grouped by the Scott Knott test at 5% probability. For multivariate analysis, seven variables were used, performed individually for each environment, resulting in two principal components, which were responsible for 82.46% and 81.87% of the total variability contained in the data. The experimental hybrids LV7xLV5, LV5xLV4, LV4xLV5, LV4xLV7 and LV1xLV6 highlights for genotypes with double aptitude. The selection of diallel hybrids base on the principal components was effective. The use of the scores of the principal components in the diallel analysis was efficient, identifyind superior genotypes for both components. There was significance in the interactions of GCA, SCA and reciprocal effect with the environments. The LV4 and LV5 lines achieved superior general combining ability for at least one of the components or environments. The hybrids LV2xLV7 and LV5xLV7 obtained favorable estimates of specific combining ability in the first principal component, with a reciprocal effect for LV2xLV7 lower in the second principal component. Only the hybrid LV1xLV2 achieved high specific ability for both components, however, only in the second environment. In view of the analyzes of specific ability and reciprocal effect, it is highlighted that the correct choice of the female parent is a decisive aspect in hybrid combinations, since the reciprocal effect was manifested in both principal components, increasing or decreasing the estimates of the diallel analysis.