Aggressiveness of Septoria Tritici Isolates on Detached and Intact Leaves of Wheat Cultivars

Abstract

Septoria tritici blotch (STB) of wheat caused by Septoria tritici Roberge in Desmaz. (teleomorph: Mycosphaerella graminicola [Fuckel] J.Schrot in Cohn) is an important disease of wheat. Recently, STB has become one of the most common foliar diseases of the crop worldwide. Aggressiveness of isolates and isolate mixtures of S. tritici was compared on detached seedling leaves mounted on water agar (0.5%) and on intact seedlings of four wheat cultivars under laboratory and glasshouse conditions, respectively. The results obtained showed that there were significant differences between isolates/isolate mixtures of S. tritici/Stagonospora nodorum in all the parameters tested. Similar significant differences were observed betweenthe isolates/isolate mixtures of the pathogen in their aggressiveness on the four cultivars tested in the two experiments. The Pearson's correlation coefficients (r values) between the parameters tested on detached and intact seedling leaves were positive and significant (p<0.05). The high positive correlations
observed between the parameters studied in the laboratory and glasshouse experiments suggest that the use of detached leaves of seedlings has considerable promise for quick screening of cultivars against the disease