New Pathogenic Variability in Uromyces appendiculatus in North America

Publisher Website
Google Scholar
Abstract
From 43 field collections of urediniospores of Uromyces appendiculatus obtained from nine states, Puerto Rico [USA] and the Dominican Republic from 1983 to 1987, new virulence combinations were identified in 13 single-uredinium isolates, described here as races 58-70. Isolates of 11 previously described races were obtained. Two of the new races have broader virulence on the cultivars used to differentiate races than the previously described North American races. Race 67 is the first to produce moderate-size uredinia on a previously resistant selection of the bean cultivar Compuesto Negro Chimaltenango. Others of these newly described races are the first to contain certain important combinations of virulence on some of the more resistant differential cultivars. The implications of these results are discussed in relation to the development of comprehensive and stable rust resistance in the common bean.