Relationship of Colletotrichum lindemuthianum races and resistance loci in the Phaseolus vulgaris L. genome

Anthracnose caused by Colletotrichum lindemuthianum is one of the most critical diseases in the common bean (Phaseolus vulgaris L.). The characterization and localization of pathogenic fungal races are essential for understanding pathogen population dynamics and developing resistant cultivars. Here, we discussed the relationship between the diversity of C. lindemuthianum and common bean resistance genes against anthracnose disease. Indeed, several studies using a system of 12 differential bean cultivars have been carried out since 1991 to monitor anthracnose, reporting the constant appearance of new races. Colletotrichum lindemuthianum shows high virulence diversity, with 298 races distributed across 29 countries. In Brazil, we identified 89 races, with races 73, 65, and 81 as the most frequent. Moreover, we highlighted the common bean gene clusters, their unique location on chromosomes, and their relationship with races and resistance genes. The genetic mapping studies, molecular markers linked to anthracnose resistance alleles, and the specific races were integrated on the seven-chromosome map using the reference genome of common bean. Recently, the ease of use of genome sequences and the development of molecular technologies have allowed molecular markers for marker-assisted selection applied to anthracnose-resistant cultivars. As a result, it is feasible that Mesoamerican genes Co-5, Co-4(2), Co-6, Co-16, and Co-17, and the Andean genes Co-1(2), Co-1(4), Co-Bf, Co-15, Co-AC, and CoPv01(CDRK) are well known to confer resistance to most races reported in Brazil and around the world. Thus, pyramiding these genes through molecular markers can help reduce the time and cost of introducing resistance genes in commercial common bean cultivars.