Identification of sources of resistance to race 63-63 of Pseudocercospora griseola in common bean lines

Angular leaf spot (ALS), caused by the fungus Pseudocercospora griseola, is one of the most important foliar fungal diseases in common bean (Phaseolus vulgaris L.). The search for new sources of resistance to ALS is a promising activity in common bean breeding programs. In this study, the reaction of 416 germplasm accessions from the Universidade Federal de Lavras (UFLA) to P. griseola (race 63-63, the most important and most aggressive race) was assessed under greenhouse conditions (plants in the V2 stage, fully developed unifoliolate leaves). We identified 102 (24.5%) resistant and 314 (75.5%) susceptible accessions. Among the resistant lines, more than half are Carioca grain type lines. This study characterizes the resistance of a wide collection of common bean genotypes. The identification of new accessions resistant to P. griseola is an important step in common bean breeding programs. These lines can continually be incorporated in backcrosses to obtain cultivars resistant to ALS.

Automated summary

This study evaluated the reaction of 416 germplasm accessions to Pseudocercospora griseola and identified 102 resistant and 314 susceptible accessions. The research showed that Carioca grain type lines have higher resistance to ALS. The discovery of new accessions resistant to P. griseola is crucial for common bean breeding programs.