Virulence of Puccinia triticina on Lr28 in wheat and its evolutionary relation to prevalent pathotypes in India.

摘要

Two new pathotypes of Puccinia triticina, 121R60-1 and 377R60-1 the latter virulent on Lr28, are described for the first time. Both the pathotypes are designated as MHTTS as per North American system of pathotype identification. Pathotype 377R60-1 appears to be the result of a single step mutation for virulence to Lr28 in pathotype 121R60-1. Both pathotypes appear closely related to the most prevalent virulent pathotype 121R63-1(THTTS). The avirulence/virulence profile, resistance sources and their possible relationship with other pathotypes are discussed. Lr28 is now included as one of the differentials for the identification of leaf rust pathotypes.