ارزیابی لاین‌های دابل هاپلوئید گندم (.Tritircum aestivum L) نسبت به بیماری سفیدک پودری

Powdery mildew disease is one of the most important wheat diseases in humid and semi-humid regions of the world. Also, powdery mildew disease has been important in Iran, and its epidemic has caused considerable damage in the northern regions of Iran in the past years. The Caspian Sea region is prone to the emergence of this disease due to high relative humidity. The use of resistant cultivars is the most economical and environmentally way to reduce the application of chemical fungicides. Doubled haploid (DH) technique reduces the time required for the development of new varieties by up to almost five years. In this study 361 doubled haploid wheat lines were evaluated as observational approach for yellow rust disease in Gorgan agricultural research station in the 2020-2021 cropping season, produced from the F2 generation. The lines were evaluated for powdery mildew disease at the adult plant stage and full emergence of flag leaf, after complete establishment of the disease on susceptible cultivar, Kalateh. Powdery mildew was recorded by Saari and Prescott methods with a scale of 00-99. Due to the favorable climatic conditions for the pathogen, in March and April, powdery mildew disease was well established and spread. The results showed that the majority of investigated lines were immune (264 lines, 73%) and no signs of infection were observed in them. Also, 13 lines (4%) were resistant and 2 lines (1%) were moderately resistant, 31 lines were moderately susceptible (9%), 36 were susceptible (10%) and 15 line (4%) were extremely susceptible to powdery mildew. Of the top 10 lines in terms of grain yield, seven and three lines were immune and susceptible, respectively.