Índice -MGIDI e EAN: análise de múltiplos cenários para seleção de progênies de meios-irmãos de milho no semiárido

Abstract

Corn is a crop with high nutritional requirements, especially for nitrogen. A deficiency of this element can restrict plant development. The objective of this study was to evaluate multiple scenarios to identify superior corn genotypes in terms of nitrogen use efficiency for the Semi-arid region, using the MGIDI selection index. Thirty-five corn genotypes were evaluated, with a spacing of 0.20 x 0.70 m. The experiment was conducted in the municipality of Nossa Senhora da Glória, during the 2024 growing season. A randomized block design with split plots and three replications was used, in which nitrogen levels (high and low) were distributed to the main plots and half-sib progenies to the subplots. The data were subjected to analysis of variance and, subsequently, to the MGIDI selection index (Multivariate Genotype-Ideotype Distance Index). Three selection scenarios were considered, resulting in distinct gains among the traits. Among them, the Mandacaru and Cacto scenarios showed greater efficiency in identifying superior genotypes. Among the genotypes evaluated, G50, G1, G22, G26, G42, G4, G34, and G16 showed greater proximity to the ideotype and superior agronomic performance, making them priority candidates for expanded trials and subsequent stages of genetic improvement focused on EAN.