بررسی واکنش مقاومت ارقام افتراقی گندم و بیماری‌زایی جدایه‌های قارچ Mycosphaerella graminicola با استفاده از روش گرافیکی GGEbiplot

Septoria tritici blotch (STB), caused by the fungal pathogen, Mycosphaerella graminicola is one of the most devastating wheat diseases, imposing a considerable annual yield loss, worldwide. In order to study resistance reaction of wheat genotypes and virulence of M. graminicola isolates, seedling response of 19 wheat differential cultivars as well as 5 susceptible controls were evaluated to 8 fungal isolates originated from Gorgan and Dezful. Wheat single-leaf seedlings were separately inoculated by spore suspensions of isolates, and the reaction of genotypes was assessed based on the percentage of leaf area covered by pycnidia at 21 days post inoculation (dpi). GGE biplot analysis based on the genotype focused model showed that cv M3 carrying Stb16&Stb17 resistance genes, and cv Veranopolis carrying Stb2&Stb6 genes are the most resistant and susceptible differential cultivars to the pathogen, respectively. GGE biplot analysis based on isolate focused model divided the 8 fungal isolates in 5 distinct groups. Gorgan isolates were classified in two separate groups of 1 and 4, while Dezful isolates were classified in groups 2, 3 and 5. This study indicates diversity in virulence and aggressiveness among the isolates.