Responses of some Promising Dryland Barley Lines to Leaf Stripe Disease Caused by Pyrenophora graminea Ito & Kurib

Forty-four barley (Hordeum vulgare) dryland promising lines, were tested for their reactions to four isolates of barley leaf stripe disease caused by Pyrenophora graminea in the greenhouse using seed inoculation method, and also in field conditions in four locations, Karaj, Gorgan, Marogheh and Miandoab, using infected seeds of susceptible cultivars as disease spreader. Because of non-conformity of flowering date between spreader and the experimental lines and/ or non-desirable environmental conditions, the disease did not develop uniformly and sufficiently on the materials in field, but in the greenhouse, lef stripe developed up to 100% on emerged seedlings. The lines were grouped into four reaction categories, based on percentage of infected seedlings. Analysis of variance of the data showed that the experimental lines differed in their reactions to the pathogen isolates, as 38% of lines were resistant, 51% moderately susceptible, 9% susceptible and 2% highly susceptible. The most susceptible lines were Pirat 1//Aljer/ceres 362-1-1 IC, T-2 (2R)//Lignee131/Arabia Abiad, Alpha//Gumhuriyet/ Ligkee 131 and Yesevi-93 and the most resistant ones 4697/105//Yea 132 TH/3/ Tipper followed by ICB-100974/Action, Alpha//Sul/Nacta/3/80-5001 and 132TH/Tokak Yia 147. Frequency of resistance reaction among lines with facultative spring and spring growth habit was higher than that of winter type lines. P. graminea isolates differed in pathogenicity at P>1% level based on the mean of percent infection of lines. This indicating physiologic specialization in population of P. graminea.