QTL mapping for angular leaf spot in common bean using microsatellite markers.

QTL identification is the first step in the application of molecular-marker-assisted selection in breeding. Common bean molecular maps are already available and QTL and, recently, SSR markers have been identified. The objective of this study was to identify QTL for reaction to angular leaf spot using segregating families from cross Jalo EEP 558 x Small White using SSR. These families presented significant differences for the trait. High heritability estimates were obtained. Environment effects and the interaction genotypes x environments influenced the trait expression. A map with 400.1 cM was established with 24 markers arranged in eight linkage groups with a mean length of 50.01 cM, and mean distance between adjacent markers of 25.01 cM. It was possible to identify steady QTL and associate them to a high percentage of phenotypic variance for reaction to angular leaf spot. BM210 and BM146 were the most outstanding markers.