Identification of QTLs of resistance to white mold in common bean from multiple markers by using Bayesian analysis.

Abstract

In this study, we identified simple sequence repeat, ampli-fied fragment length polymorphism, and sequence-related amplified poly-morphism markers linked to quantitative trait loci (QTLs) for resistance to white mold disease in common bean progenies derived from a cross between lines CNFC 9506 and RP-2, evaluated using the oxalic acid test and using Bayesian analysis. DNA was extracted from 186 F₂ plants and their parental lines for molecular analysis. Fifteen experiments were car-ried out for phenotypic analysis, which included 186 F₂:₄ progenies, the F₁ generation, the F₂ generation, and the lines CNFC 9506, RP-2, and G122 as common treatments. A completely randomized experimental design with 3 replications was used in controlled environments. The adjusted means for the F₂:₄ generation were to identify QTLs by Bayesian shrink-age analysis. Significant differences were observed among the progenies for the reaction to white mold. The moving away method under the Bayes-ian approach was effective for identifying QTLs when it was not possible to obtain a genetic map because of low marker density. Using the Wald test, 25 markers identified QTLs for resistance to white mold, as well as 16 simple sequence repeats, 7 amplified fragment length polymorphisms, and 2 sequence-related amplified polymorphisms. The markers BM184, BM211, and PV-gaat001 showed low distances from QTLs related white mold resistance. In addition, these markers showed, signal effects with increasing resistance to white mold and high heritability in the analysis with oxalic acid, and thus, are promising for marker-assisted selection.