Pathogenic diversity of Phaeoisariopsis griseola in Costa Rica

摘要

In Costa Rica, the common bean (Phaseolus vulgaris L.) is one of the most important components of diet, and the principal source of protein for human population. This crop is attacked by a large number of diseases. Angular leaf spot (ALS), caused by the fungus Phaeoisariopsis griseola (Sacc.) Ferraris, is widespread, and its incidence and severity, has increased in the last ten years in Costa Rica (Araya & Araya, 2000). The reaction of bean varieties to natural population of the pathogen vary considerably from one location to another, because of the presence of multiple races, that infect determined varieties of bean, with a different range of severity. A major part of bean production comes from medium, small and subsistence farmers, who have significant yield reduction and therefore economical looses due to the presence of P. griseola and other pathogens. The development and use of resistant cultivars offer the only economical means for disease control (Sartorato et al., 2000), With that intention since the middle of the ninetieth decade, different sources of resistance and potential gene donator have been evaluated in Costa Rica (Araya & Araya, 2000).