Sources of resistance to two physiolocic races of Colletotrichum lindemuthianum in bean breeding in southern Brazil

Abstract

This paper deals with the research of sources resistant to Colletotrichum lindemuthianum. (Sacc. et Magn.) Serib., the fungus of bean anthracnose, one of the most serious diseases of beans in Brazil. It is necessary to know which varieties are suitable for hybridizing, in the search for resistant varieties which is one of the most important objectives of bean breeding. The investigations were conducted in the greenhouse and the laboratory through immunological tests in which seedlings of varieties and strains were submitted to pathogen infection. The data showed that only Perry Marrow, Asgrow Valentine and Barão Ibiruba-1 were resistant to both physiological races of anthracnose found in Rio Grande do Sul, namely alfa and beta. These varieties are being used in the bean breeding program at the Instituto de Pesquisas e Experimentação Agropecuárias do Sul. The other varieties were resistant to one race and susceptible to the other or showed susceptibility to both races. In some varieties both susceptible and resistant seedlings appeared. The majority of the varieties studied have resistant genes to beta race, a situation which does not occur in relation to alfa race.