Sources of powdery mildew resistance in a wild barley collection

A total of 1,383 accessions of wild barley (Hordeum vulgare ssp. spontaneum) held in the USDA-National Small Grains Collection, Aberdeen were screened for resistance to powdery mildew (Blumeria graminis f. sp. hordei) in the Czech Republic. They were subsequently tested at the seedling stage for reaction to selected powdery mildew pathotypes and simultaneously for their adult plant resistance in the field. One hundred and twenty-three accessions exhibited resistance to 22 pathotypes in the greenhouse tests (reaction type 2–3 or lower) as well as resistance to the natural population of this pathogen in the field in the Czech Republic during at least 2-year testing. These accessions represent large amount of promising sources in breeding barley for resistance to powdery mildew.