Inheritance of Anthracnose Resistance in the Common Bean Differential Cultivar G 2333 and Identification of a New Molecular Marker Linked to the Co‐4 2 gene

The inheritance of anthracnose resistance of the common bean ( Phaseolus vulgaris L.) differential cultivar G 2333 to Colletotrichum lindemuthianum races 73 and 89 was studied in crosses with the susceptible cultivar Rudá. The segregation ratios of 15 : 1 in the F 2 and 3 : 1 in the backcrosses to Rudá indicate that for each of the races tested there are two independent resistance loci in G 2333. A random amplified polymorphic DNA (RAPD) molecular marker (OPH18 1200C ) linked in resistance to race 73 was identified in a BC 3 F 2:3 population derived from crosses between Rudá and G 2333. A RAPD molecular marker OPAS13 950C , previously identified as linked to gene Co‐4 2 , was also amplified in this population. Co‐segregation analyses showed that these two markers are located at 5.6 (OPH18 1200C ) and 11.2 (OPAS13 950C ) cM of the Co‐4 2 gene. These markers were not present in BC 1 F 2:3 plants resistant to race 89 indicating that this population carries a different resistance gene. DNA amplification of BC 1 F 2:3 plants with RAPD molecular marker OPAB 450C , previously identified as linked to gene Co‐5 , indicated that this gene is present in this population.