Sources of Resistance to Anthracnose in Traditional Common Bean Cultivars from Paraná, Brazil

AbstractPathogenicity of physiologically distinct races of Colletotrichum lindemuthianum originating from Andean (races 7, 19 and 55) and Mesoamerican (races 9, 31, 65, 69, 73, 81, 89, 95 and 453) locations of the new world were evaluated on 26 landrace genotypes of common bean (Phaseolus vulgaris L.) from Paraná State, Brazil. Races 7 (Andean), 65, 73 and 89 (Mesoamerican) were the most pathogenic, while race 31 (Mesoamerican) was the least pathogenic. Most of the landrace genotypes evaluated (88%) were resistant to race 31, except Carioca 3, Preto 1 and Preto 2. In addition, about 50% of the landrace genotypes had resistance to races 9, 19, 55 and 453; and about 30% to races 7, 65, 69, 73, 81, 89 and 95. The resistance index, which measured the pathogenicity response averaged across all the physiologically distinct Andean and Mesoamerican races of C. lindemuthianum, of the landrace genotypes ranged from 8% to 83%. The most resistant cultivars were Carioca Pintado 1, Carioca Pintado 2, Jalo Vermelho and Jalo de Listras Pretas. In contrast, the most susceptible cultivars were Jalo Pardo, Jalo Pintado 1 and Bolinha that showed resistance only to the least pathogenic race 31. These results indicated that many of the common bean landrace cultivars evaluated have genes that could be useful in breeding programmes to enhance resistance to Andean and Mesoamerican races of C. lindemuthianum.