Agrarian (Oct 2019)
Identification of potential soybean crosses for grain yield in the F2 generation
Abstract
The diallel schemes comprise a powerful strategy for the genetic study of the characters and the ability to match the parents, as well as to obtain information at the different stages of a genetic breeding program involving artificial hybridizations. It presents special importance for the adequate selection of the parents in generations of endogamy after the hybridization. The objective of the study was to evaluate the combining ability, heterosis and heritability in 15 soybean genotypes using a 10 x 5 partial diallel. Group I of parents was composed of ten experimental lines (USP) with high grain yield and group II was composed of five parents with resistance to white mold, as indicated in literature. Two experiments were installed to estimate the general (GCA) and specific (SCA) combining ability, one with the 50 crosses and the another with the 15 parents. At the R8 stage, grain yield (GY) of the crosses and the parents was evaluated. The comparison of means between the genotypes and heterosis was also calculated. Broad-sense heritability was estimated considering phenotypic, environmental and genotypic variances. The results indicated superiority of the crosses in comparison to the parents. Heritability was considered high for most crosses evaluated. Diallel analysis was effective in identifying F2 populations with higher genetic gain potentials.
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