Gains from selection for oil content in cotton

With the growing demand for biodiesel, there is greater interest in increasing the oil content of cotton cultivars; this has made cotton breeding programs incorporate this trait in selections. Screening studies on the germplasm bank of Embrapa Algodao have shown variability for this trait. This study aimed to select cotton segregating genotypes in the F-5 generation by estimating genetic and phenotypic parameters, such as heritability, and gains from direct and indirect selection. Thus, we selected three accessions with high oil content, which are, BRS Aroeira, Acala 1.13-3-1 e 149 FURRS, which were crossed with inbred lines more productive fiber of the breeding program of Embrapa Algodao, making a total of nine types of crosses. The generations were defined by pedigree method, always using selection between and within progenies for higher oil content. The analyzes were determined from F-3 seeds, which were conducted until the F-5 generation with line 22, these evaluated in a completely randomized trial with 4 replications; for each replication, three oil content analysis were made. For the analysis of variance, it was used the mean of these three valuation. The estimated data of the oil content of the studied generations enables the estimation of: phenotypic, genotypic and environmental variance; heritability through parent-progeny regression, being F-3 (parent) and F-5 (progeny); and the achievement of genetic gain. It was determined that there was genetic variation among genotypes, indicating the possibility of obtaining gains through between and within selection of progenies, and that F-5 generation is more appropriate to maximize genetic gain from selection for seed oil content in cotton. The estimated genetic gain in F-5 generation corresponded to 4.98%, which is higher than in F-3 generation, denoting that selection for the character is far more efficient when performing direct selection in F-5. CNPA 2011/12 line presents the potential to be used as a parent in breeding programs which aim at improving the oil content of cotton. (C) 2013 Elsevier B.V. All rights reserved.