Reaction of Bread Wheat Advanced Genotypes to Mycosphaerella graminicola the Causal Agent of Septoria tritici Leaf Blotch in Greenhouse and Field Conditions

To assess the reaction of bread wheat advanced genotyoes to septoria tritici leaf blotch (Mycosphaerella agraminicola), 33 genotypes with a susceptible cheack cultivar Tajan were evaluated in greenhouse and field during 2009-2010 cropping season. In greenhouse, seedlings were inoculated with spore suspension of Septoria tritici and maintained under plastic covers in saturated humidity at 20ºC. In field, wheat genotypes were inoculated with spore suspension under irrigation system at three growth stages. The reaction of genotypes were evaluated by assessing leaf necrosis area and pycnidial coverage percentage in both experiments. Area under disease progress curve (AUDPC) was also calculated for each genotype used in these experiment. Analysis of variance showed significant differences among genotypes for leaf necrosis area and pycnidial coverage at 1% and 5% probability levels, respectively. Lines N-87-18 and KST10 had the highest and lowest leaf necrosis area in greenhouse, respectively. The highest AUDPC was calculated for line N-87-17 and the lowest for KST10. In field, genotypes differed significantly for leaf necrosis aea at 1% level. Lines N-87-19 and N-85-10 had the highest and the lowest leaf necrosis area, respectively. Line KST9 had the highest and line N-85-10 the lowest AUDPC 0