Investigating the mode distribution of Septoria leaf blotch and evaluating the resistance of wheat cultivars in Golestan province

In this research, examineation of the disease distribution, the physiological relationship between disease agent and its sites and evaluation of cultivars resistance were done. The disease agent identified as Zymoseptoria tritici, by morphological and molecular identification based on the ITS-rDNA. Distribution map prepared by ArcGIS v.10.2 software. Five isolates selected from different regions. The isolates growth tested in different temperature and its relation to their region climatic conditions evaluated. 26 cultivars planted in the greenhouse by completely randomized design, inoculated and evaluated. As a result, the isolates growth average at different temperatures was statistically significant in P=0.01. Isolate growth average had correlation with region climatic conditions. In terms of growth, the Nokandeh isolate was the most and the Ramian isolate was lowest. The highest isolates growth was at 15°C and the lowest growth rates were at 10°C. The disease observed in 9 eparchies. Ramians and Kurdkoy identified as disease contaminated sites. Of the examined cultivars, 4 cultivars such as Falat, Mehrgan, Ghabos, and Roshan were resistant, 14 cultivars such as Shirodi, Morvarid, Moghan, Kohdasht, Gaspar, Aftab, Shahriar, Gonbad, Alamoot, Aflak, Zarin, Karaj-1, Tous, and Azar-2 were moderately resistant and 7 cultivars such as Karim, Dez, Khazar-1, Star, Hamoon, Ofogh, Eram and Tajan were evaluated as susceptible. Between isolates, the most disease severity belongs to Ramian. Considering to width distributions of STB, the existence of favorable conditions and identification of disease region center, it is possible to monitor the appearance of infection at February and March and make abroadcast of the disease prevalence. Also, by evaluating of wheat genotypes, introducing and planting the resistant cultivars, it could reduce the disease in later years.