Study on Virulence Factors of Mycosphaerella Graminicola, the Causal Agent of Septoria Leaf Blotch, and Reactions of Some Iranian Wheat Genotypes to this Pathogen in Iran

Wheat Septoria leaf blotch disease caused by Mycosphaerella graminicola is one of the most important diseases of wheat in Iran and the world .Evaluation the reaction of wheat genotypes and on the other hand identifying pathogen virulence factors are necessary for a successful breeding program. The aim of this study was to assess the adult plant responses of Iranian bread and durum wheat genotypes developed by Iranian seed and plant improvement institute to Septoria tritici leaf blotch and study on virulence factors of this pathogen in harm and humid conditions in the south of Iran. The study was conducted in Khuzestan province of Iran in two years (2013-2014 and 2014-2015) and included 47 commercial verities and 26 differential lines whit a local pathogen isolate that was collected on a bread wheat variety. Taking notes was performed with a modified Saari and Prescott method in double-digit scale 00–99. From Commercial varieties only 5 varieties were resistant .Even the durum varieties like Behrang and Karkhe were susceptible. Results of differential set showed pathogen isolate of this region has virulence reaction for stb2,stb3,stb4,stb6,stb7, stb8,stb9,stb10, stb12,stb13,stb14 and stb18 genes and for stb1, stb5, stb11, stb15, stb16, stb17 genes is Avirulance.