Evaluation of resistance to powdery mildew in genotypes of Preliminary, Advanced, and Elite Irrigated Barley Yield Trials (PBYT- ABYT-EBYT).

In this study, 678 primary, advanced, and elite barley yield lines (PBYT- ABYTEBYT) were evaluated for resistance to Powdery Mildew in adult plant and seedling stages in 2009-2010 cropping season. The lines were planted in research fields in Karaj and Mashhad (as Cold & Moderate zone), Gorgan and Dezful (as Warm zones). Seedling plants were tested in greenhouse in Karaj. In field , susceptible local cultivars were planted among the lines and also around the nurseries. Data on disease severity and responses of the lines were taken according to Saari & Prescott (1975) modified by Eyal et al.,(1987). Results showed that, at adult plant stage, among of cold zone genotypes in Mashhad, 161 lines were imune and 36 lines were resistant, 23 lines were moderately resistance, 13 lines were suseptible. In seedling stage for this genotypes, 41 lines were moderately resistant, 192 lines were susceptible. Among of moderately genotypes, in Mashhad, 182 lines were imune and 49 lines resistant, 92 lines moderately resistant, and 29 lines were suseptible. in Gorgan, 78 lines were imune, 111 lines resistant, 120 lines moderately resistant , 11 moderately susceptible and 32 lines were susceptible. In seedling stage, among of this genotypes, 6 lines were imune, 4 lines were resistant, 22 lines moderately resistant, 311 susceptible and 9 were without germination. oderately resistant, 159 susceptible, and 3 lines were resistant to susceptible. Among of warm genotypes, in Gorgan , 29 lines were imune, 28 lines were resistant, 30 lines were moderately resistant and 3 lines were moderately susceptible and 3 lines were suceptible. In dezful, 56 lines without any symptom and 7 lines were moderately resistant and 30 lines were susceptible. In seedlig stage, 6 lines were imune, 6 lines resistant, 18 lines moderately resistant and 63 lines were susceptible.