evaluation of some iranian wheat landraces resistance against stem rust disease at seedling stage in the green house

wheat is the most important crop of iran and black or stem rust disease is one of the most severe diseases threatning the wheat production. in order to identify new resistant sources against the new race of stem rust virulent on plant with sr 31gene, the selected iranian landraces accessions of national plant gene bank of iran wheat collection were evaluated. the most virulent isolate of puccinia graminis f.sp. tritici (pgt) that was from dasht-azadegan was used. isolate purity was tested by propagation of single pustule on seven days seedling of boulani susceptible cultivar in the green house. pathotype identification was carried out by 45 differential lines of wheat stem rust received from icarda. the pathotype used was pathogenic against sr31, sr36, sr38 and sr13 but it was not pathogenic against sr24. during this study, 62 iranian landrace accessions were evaluated for resistance against pgt at seedling stage in the greenhouse. seven days seedlings were inoculated by spore suspension. 14 days after inoculation based on stackman et al. method, infection type was recorded. according to the results, the landrace accessions were divided into susceptible and resistant groups. the resistant group included 39 landrace accessions. complementary analysis for identification of resistance genes by molecular markers is in progress.