Occurrence of anthracnose pathogen races and resistance genes in common bean across 30 years in Brazil

Abstract

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 recommending strategies to develop resistant cultivars. As resistant genotypes are the most economical and ecologically safe means of controlling plant diseases, there have been efforts to characterize resistance genes in common bean. Several studies using a system of 12 differential bean cultivars have been carried out to monitor anthracnose since 1991, reporting the constant appearance of new fungal races. C. lindemuthianum shows high virulence diversity. The objective of the present study was to review the relationship between C. lindemuthianum races and the common bean pathogenic processes involved in the risk of developing anthracnose disease. As a result, 89 races occurred in Brazil, wherein 73, 65, and 81 of C. lindemuthianum are the most frequent. Furthermore, we built a map with the anthracnose resistance loci, molecular markers, and their respective physical position. The accessibility to the genomes and sequencing technologies permits molecular markers for marker-assisted selection applied to anthracnose-resistant cultivars. This study could be used as a reference for future resistance mapping studies and as a guide for selecting resistance loci in breeding programs aiming to develop common bean cultivars with durable anthracnose resistance.