Evaluation of Resistance of some Wheat Cultivars and Lines to Septoria Leaf Blotch at Seedling and Adult Plant Stages

In this study، resistance of 230 wheat elite lines and commercial cultivars was evaluated to Mycosphaerella graminicola، the fungal pathogen of septoria leaf blotch، at seedling and adult plant stages (in greenhouse at Cereal Pathology Unit، Seed and Plant Improvement Institute، Karaj، and in experimental fields of Gorgan Research Station، respectively). The first leaves of seedlings of wheat genotypes were separately inoculated with three high virulent isolates of the pathogen. Seedling resistance was visually assessed based on percentages of leaf necrotic area and pycnidial coverage at 21 days post inoculation. Results showed that 49، 25 and 34% of genotypes were resistant to the pathotypes 87001، 87051 and 88005، respectively، whereas the rest showed various levels of susceptibility. The wheat cultivar Darya and the lines S-87-1، S-87-10، S-87-15، S-87-16، S-87-17، S-87-18، S-87-20، S-87-22، C-86-1، C-86-5، C-85-4، C-85-6، C-85-9، C-81-10، C-80-4، N-86-12، N-83-3 and M-85-16 were resistant to all three isolates. Evaluation of adult plant resistance scored by 00-99 modified scale، showed the resistance reaction for 39% of the genotypes. Over 50% of plant materials were susceptible to the pathogen isolates at seedling and adult plant stages. Wheat genotypes with acceptable levels of resistance could be used as sources of resistance in wheat breeding programs.