Recent occurrence of Puccinia graminis f. sp. tritici in Italy: Pathogen virulence composition and seedling resistance of durum and common wheat

Regular disease monitoring is currently carried out in the most important Italian wheat growing areas. In 2007–08 stem rust was absent in all locations tested except Montelibretti (Rome, Central Italy), where two common wheat varieties “Arsenal” and “Compair” had stem rust infections. Two stem rust pathotypes were identified by testing in the greenhouse a set of differential lines/varieties carrying known genes for resistance to Puccinia graminis. These pathotypes corresponded to races MSK and PTK on the basis of the North American classification system. Genes Sr24 and Sr25 (both derived from Thinopyrum ponticum) and Sr31 (from Secale cereale), were resistant to the Italian pathotypes, and the lines carrying Sr38 (from Triticum ventricosum) were susceptible.