SCAR, RAPD AND RFLP MARKERS LINKED TO A DOMINANT GENE (ARE) CONFERRING RESISTANCE TO ANTHRACNOSE IN COMMON BEAN

Anthracnose, caused by the fungus Colletotrichum lindemuthianum, is a severe disease of common bean (Phaseolus vulgaris L.) controlled, in Europe, by a single dominant gene, Are. Four pairs of near-isogenic lines (NILs) were constructed, in which the Are gene was introgressed into different genetic backgrounds. These pairs of NILs were used to search for DNA markers linked to the resistance gene. Nine molecular markers, five RAPDs and four RFLPs, were found to discriminate between the resistant and the susceptible members of these NILs. A backcross progeny of 120 individuals was analysed to map these markers in relation to the Are locus. Five out of the nine markers were shown to be linked to the Are gene within a distance of 12.0 cM. The most tightly linked, a RAPD marker, was used to generate a pair of primers that specifically amplify this RAPD (sequence characterized amplified region, SCAR).