INHERITANCE OF ANTHRACNOSE RESISTANCE IN COMMON BEAN ACCESSION G-2333

Common bean (Phaseolus vulgaris) germ plasm accession G 2333 (Colorado de Teopisca) from Mexico was resistant to 380 isolates of the anthrac nose pathogen (Colletotrichum lindemuthianum) from 11 Latin American c ountries. Six frequently used sources of resistance were susceptible t o many isolates. Inheritance of resistance was studied in a cross of r esistant G 2333 X susceptible ICA Pijao. The two parents and the F1, F 2, and backcross generations were inoculated with race 521 in both the seedling and adult-plant stages in controlled greenhouse environments at CIAT. Two independent dominant genes controlled resistance in the seedling and adult-plant stages, giving a segregation ratio of 15 resi stant to 1 susceptible in the F2, all resistant in the backcross to G 2333, and 3 resistant to 1 susceptible in the backcross to ICA Pijao.