Seleção fenotípica e assistida por marcadores moleculares de famílias de feijoeiro-comum com alta produtividade

Abstract

The objective of this work was to select common bean families with high grain yield, using phenotypic and marker-assisted selections (MAS). Evaluations were made for 394 families of four populations and their six parents, in Lavras county, Minas Gerais, Brazil. Two field experiments were conducted: one in the F3:4 generation, in the rainy season of 2005/2006, using a 20x20 simple lattice design; and other in the F3:5 generation, in the dry season of 2006, using a 20x20 triple lattice design. Genetic and phenotypic parameters were estimated, and the families were genotyped with microsatellite markers for grain yield quantitative trait loci (QTL), that had been identified previously. Simple marker association analysis was performed between markers and grain yield, and an index was estimated for MAS. The high variability between families and the heritability estimates made high genetic gains possible through phenotypic selection. The markers explained a small percentage of phenotypic variation, and presented high QTL x environment and QTL x population interactions. The MAS achieved small gains, with low coincidence of families selected by both methodologies, showing, in this case, that the MAS inefficiency was mainly due to the low number of available markers. © 2009 Embrapa Informação Tecnológica.