Genetic potential of F3 and F4 soybean populations derived from diallel crossing
The selection of superior parents and promising hybrid combinations is a fundamental step in soybean breeding programs. Diallel analysis allows the estimation of the effects of general (GCA) and specific (SCA) combining ability, contributing to the identification of potentially superior lines. The objective of this study was to evaluate traits related to earliness, yield components, and yield in segregating soybean populations in the F3 and F4 generations. The experiments were conducted at the Capim Branco Experimental Farm of the Federal University of Uberlândia during the 2023/2024 and 2024/2025 growing seasons. Six populations originating from diallel crosses and their parents were evaluated in a randomized block design with ten replications. The data were subjected to analysis of variance and diallel analysis using Griffing's method II, fixed model. Significant differences were found between the genotypes, highlighting genetic variability and potential for selection. Predominant additive gene effects were observed, with high heritability estimates for total number of pods, number of pods with two grains, and number of days to flowering. The BRS 511 cultivar proved favorable as a parent for reducing the cycle and increasing the total number of pods in the F3 and F4 generations. The NA7337 cultivar is promising for the development of soybean populations aimed at increasing grain yield, according to diallel analysis in the F4 generation. For the selection of early-cycle progenies with higher grain yield, the NA 7337 RR x BRS 511 combination showed promise for the selection of soybean progenies in a genetic improvement program.