A GENETIC-MAP OF COMMON BEAN TO LOCALIZE SPECIFIC RESISTANCE GENES AGAINST ANTHRACNOSE

A bean genetic map was developed to locate resistance genes against an thracnose and genes involved in plant defense mechanisms. One hundred and fifty-seven markers (51 restriction fragment length polymorphism, 100 random amplified polymorphic DNA, 2 sequence characterized amplifi ed regions, and 4 morphological markers) were used to construct a gene tic map covering 567.5 cM of the bean genome. Morphological markers co nsisted in two resistance genes towards anthracnose (Are and RVI), a d ominant gene for nuclear male sterility (Ms8) and a pod-shape characte r (SGou). This map was established by using a backcross population (BC 1) of 128 individuals, derived from a cross between two European bean genotypes: Ms8EO(2) and Corel. Nine percent of the markers showed segr egation distortions and mapped to three regions. Clusters of 2-10 mark ers were observed in every linkage group. The possible origin of these clusters is discussed. Nineteen markers shared with a previously publ ished bean linkage map allowed us to establish a preliminary correspon dence between the two maps. Finally, seven genes involved in plant def ense mechanisms were located on this map.