GENETIC DIVERSITY IN PHAEOISARIOPSIS GRISEOLA BASED ON ISSR MOLECULAR MARKERS

摘要

Angular leaf spot is a disease of bean (Phaseolus vulgaris) caused by the fungus Phaeoisariopsis griseola (Sacc.) Ferraris which occurs in tropical and subtropical cultivated areas around the word, causing important economic losses in Latin America where 20% of the world beans are produced. In Argentina, beans are mainly grown in the northwestern provinces of Salta, Tucuman and Jujuy, where the disease can provoke losses as high as 80%. Pastor-Corrales and Jara (1995) defined within the pathogen twomajor groups: Andean and Mesoamerican. According to these authors, these two groups might have co-evolved with Andean and Mesoamerican beans, respectively. Pastor Corrales et al. (1998), Busogoro et al. (1999), Stenglein and Balatti (2006) identified variability between isolates of P. griseola not only at DNA level but also in the interaction with bean cultivars. Genetic diversity of the pathogen, P. griseola is crucial to develop a breeding program aimed at obtaining common bean cultivars tolerant to angular leaf spot.