Seleção de genótipos de milho por meio do índice MGIDI para cultivo em região semiárida

Abstract

Corn (Zea Mays. L) is a crop of great social and economic importance, used in human and animal food, has great relevance in the semi-arid region of Sergipe, which makes it necessary to improve the crop, to carry out cultivation in regions that have biotic and abiotic stresses. The objective of this study was to select productive maize hybrids in the semiarid region using the MGIDI index. The experiment was carried out at the Embrapa Semi-arid farm in 2023 in the municipality of Nossa Senhora da Glória - SE. The experimental design was randomized blocks, with 20 genotypes, two replications and a population density of 71,428 plants per hectare. The variables analyzed were plant height, ear height, relative position of the ear, male flowering, female flowering and grain yield per hectare. Principal component analysis explained 87.2% of the observed variability, allowing an accurate multivariate study. The analysis of factor loadings showed the variables plant height, ear height and relative position of the ear as predominant in the structure factor, female flowering and grain yield in the floregron factor and male flowering in the precocity factor. Heritability in the broad sense above 67% was observed and a selection gain of -0.53% for plant height, 1.98% for ear height, 2% for relative position of the ear, 0.48% for female flowering, 0.57% for male flowering and 5.73% for grain yield. The MGIDI index provided the desirable selection differential for ear height -2.24%, relative ear position 2.6% and grain yield 8.56%. 3 genotypes were selected, G44, G59 and G60 that showed aptitude for structure characteristics, precocity and floregon. The G60 is an experimental hybrid that has potential for use in breeding programs.