Molecular and Phenotypic Mapping of Genes Controlling Seed Coat Pattern and Color in Common Bean (Phaseolus vulgaris L.)

Common bean (Phaseolus vulgaris L.) exhibits a wide variety of seed coat patterns and colors. From a historical perspective, extensive genetic analyses have identified specific genes that control seed coat pattern (T, Z, L, J, Bip, and Ana) and color (P, C, R, J, D, G, B, V, and Rk). Many of these genes exhibit epistatic interactions with other genes, interactions that define the many seed coat patterns and colors observed within the species. To better understand these complex interactions, we began a molecular marker discovery program that previously identified random amplified polymorphic DNA (RAPD) markers linked to many of these genes. We report here the discovery of RAPD markers linked to three additional genes-C, G, and V. These markers, and five RAPD markers we previously discovered linked to other seed coat pattern and color genes, were converted into easily scorable sequence tagged site (STS) markers. We next placed these markers onto a common molecular map shared by the Phaseolus research community and demonstrated a generally wide distribution of the genes throughout the common bean genome. A few previously unrecognized linkages were discovered. The probable existence of multiple genes controlling growth habit in common bean is discussed. Our approach demonstrates the usefulness and feasibility of marker discovery in one population followed by accurate mapping of that marker onto a core, community-wide map.