Phaeoisariopsis griseola is the causal agent of common bean (Phaseolus vulgaris L.) angular leaf spot, considered one of the most important bean diseases in the State of Minas Gerais, Brazil. Aiming at identifying RAPD markers closely linked to the angular leaf spot resistance genes (race 63.39 - mesoamerican origin), a previous study of their inheritance was carried out. Populations derived from the cross Rudá (susceptible) x MAR-2 (resistant) both mesoamerican genetic materials, were evaluated as to disease behaviour. F2 generation presented segregation of 3:1 (resistant: susceptible); 1:1 for the backcross to the susceptible parent (Rudá) and 1:0, for the backcross to the resistant one (MAR-2). These results strongly suggested that one dominant gene is in charge of the patogen resistance. Resistant and susceptible DNA bulks, extracted from the F2 population, were set up and amplified with 400 primers. Bulks amplified with primer OPE-04 gave rise to a 500 bp fragment, which co-segregated with the resistance gene. Co-segregation analysis revealed that this marker is linked to the pathogen resistance gene, at a distance of 5.8 cM.
RAPD markers; resistance gene; common bean; Phaseolus vulgaris; Phaeoisariopsis griseola
