Resistance Sources to Septoria Leaf Blotch in Selected Wheat Genotypes

Septoria tritici blotch (STB) caused by Mycosphaerella graminicola is one of the most important diseases theating wheat crop worldwide. Use of resistant cultivars is the most effective and economically way to control the disease. To evaluate and identify sources of resistance to STB among wheat genotypes at seedling stage، infected leaf samples were collected from different ares of Khuzestan province during 2010-2011 cropping season. After purification and preparation of several isolates of the pathogen، four most virulent isolates were selected and inoculated on primary leaves of seedlings of 219 wheat cultivars and advance lines together with four check cultivars selected from breeding materials of Seed and Plant Improvement Institute، Karaj، Iran. Resistance of genotypes were evaluated based on reaction types of seedlings on day 21 after inoculation، pecentage of necrotic areas and pycnidial coverage. Based on the results، eight cultivars Arina، Riband، M3، Arya، Shotordandan، Karkheh، Soison and Chamran were resistant to all four isolates. Line Sep-49 was resistant to two isolates 90014 and 90018 but susceptible to isolates 91001 and 91002. Lines Sep-58 and Sep-59 were also susceptible to isolate 91002 but resistant to other three isolates. The remaining genotypes were susceptible to all four isolates.