The causal agent of anthracnose (Colletotrichum lindemuthianum) of common bean and its host, are classified as Andean and Mesoamerican. Response to infection depends on the genetic origin of both plant and fungus. The objective this study was to evaluate 220 accessions from Common Bean Germplasm Collection of Instituto Agronômico, IAC, us to infection by three physiological races of the pathogen (31, 65 and 89), and to investigate a possible co-evolution between the origin of the accessions and the pathogen. One hundred and twenty accessions of Mesoamerican origin, 57 Andean and 43 genetically improved cultivars were used in the study. Besides infection data, 23 morpho-agronomic descriptors were evaluated to characterize the plants. Statistical analyses were based on principal components as a way of showing in graphics the variability related to origin of pathogen and accessions. Fifty percent of the Mesoamerican accessions were susceptible to the three races, while only 33% of the Andean were susceptible. Also, of the genetically improved cultivars 79% were resistant to at least one physiological race, probably due to previous selections for resistance to C. lindemuthianum. Diagrams of the analysis of the principal components, showed that most of the resistant accessions clustered in the dispersion region of the Andean accessions. The results allowed the association between the origin of Phaseolus vulgaris and the anthracnose pathogen, increasing the biological understanding of the reaction defense to C. lindemuthianum infection, and orienting the choice of parents to be used in crossings aiming at resistance to C. lindemuthianum.
Phaseolus vulgaris; bean; anthracnose; principal components; resistance
