ADAPTATION OF WHEAT RUSTS TO THE WHEAT CULTIVARS IN FORMER CZECHOSLOVAKIA

In former Czechoslovakia virulence of rusts attacking wheat was studie d since the sixties. Since the same time genes for resistance in the r egistered cultivars were identified. The role of Berberis and Thalictr um as alternate hosts for stem rust and leaf rust, respectively, was i nvestigated as well. Determined changes of virulence in rust populatio ns could only partially be ascribed to changes of resistance genes in the grown cultivars. Unnecessary genes for virulence had no negative e ffect on the fitness of the pathogen. All tested samples of aeciospore s from barberries attacked rye, not wheat. None of Thalictrum species occurring in the Czech and Slovak Republics was found to host wheat le af rust. However, the sexual stage of wheat stem rust and wheat leaf r ust could be induced on Berberis vulgaris and Thalictrum speciosissimu m, respectively. General epidemiological conclusions are drawn from th e results and experience of the last 35 years.