Evaluation of Resistance of some Wheat Advanced Lines to Pathotypes of Wheat Powdery Mildew at Seedling and Adult Plant Stages

Resistance of 60 advanced lines of wheat to three pathotypes of powdery mildew fungus collected from Gorgan, Moghan and Varamin was evaluated in greenhouse conditions. Infected samples of wheat were collected from different provinces in 2005 and transferred to the greenhouse. After purification and multiplication of spores on susceptible cultivar Bolani, pathotypes of the pathogen were determined by inoculating pure spores of each isolate separately on the first leaves of 17 near isogenic lines(differentials) in the greenhouse. Pure spores of each pathotype were then inoculated separately on the first leaves of advanced lines. Infection types were assessed based on 0 to 9 scale, 12 and 16 days after inoculation. All lines were susceptible at seedling stage. In field experiment, in Gorgan Agricultural Research Station, line N-83-13 was highly resistant,33 lines were resistant and the remainings were moderately susceptible. Susceptible reactions of those lines at seedling stage and resistance reactions at adult plant stage indicated that they may carry adult plant resistance.