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 vul garis L.) differential cultivar G 2333 to Colletotrichum lindemuthianum rac es 73 and 89 was studied in crosses with the susceptible cultivar Ruda. The segregation ratios of 15:1 in the F-2 and 3 : 1 in the backcrosses to Ruda indicate that for each of the races tested there are two independent resis tance loci in G 2333. A random amplified polymorphic DNA (RAPD) molecular m arker (OPH18(1200C)) linked in resistance to race 73 was identified in a BC 3F2:3 population derived from crosses between Ruda and G 2333. A RAPD molec ular marker OPAS13(950C), previously identified as linked to gene Co-4(2), was also amplified in this population. Go-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 BC1F2:3 plants r esistant to race 89 indicating that this population carries a different res istance gene. DNA amplification of BC1F2:3 plants with RAPD molecular marke r OPAB(450C), previously identified as linked to gene Co-5, indicated that this gene is present in this population.