Inheritance of Anthracnose Resistance in the Common Bean Differential Cultivar G 2333 and Identification of a New Molecular Marker Linked to the Co-42 gene

The inheritance of anthracnose resistance of the com- mon bean (Phaseolus vulgaris L.) di€erential cultivar G 2333 to Colletotrichum lindemuthianum races 73 and 89 was studied in crosses with the susceptible cultivar Ruda . The segregation ratios of 15 : 1 in the F2 and 3 : 1 in the backcrosses to Ruda indicate that for each of the races tested there are two independent resistance loci in G 2333. A random ampli®ed polymorphic DNA (RAPD) molecular marker (OPH181200C) linked in resistance to race 73 was identi®ed in a BC3F2:3 population derived from crosses between Ruda and G 2333. A RAPD molecular marker OPAS13950C, previ- ously identi®ed as linked to gene Co-42, was also ampli®ed in this population. Co-segregation analyses showed that these two markers are located at 5.6 (OPH181200C) and 11.2 (OPAS13950C) cM of the Co-42 gene. These markers were not present in BC1F2:3 plants resistant to race 89 indicating that this population carries a di€erent resistance gene. DNA ampli®cation of BC1F2:3 plants with RAPD molecular marker OPAB450C, previously identi®ed as linked to gene Co-5, indicated that this gene is present in this populatio