SEEDLING RESISTANCE IN HORDEUM TO BARLEY STRIPE RUST FROM TEXAS

Stripe rust of barley was recently found in Texas, and the pathogen has been reported to be virulent to U.S. barley cultivars. The stripe rust isolate collected in Texas was used to evaluate the resistance of barley cultivars, germ plasm, and other Hordeum species. Limited sources of resistance were found; most were from two of the five primary barley-growing areas. The resistance traces to Czechoslovakia and Ethiopia land cultivars and to the cultivar Derr Winter of unknown origin. The U.S. cultivars with seedling resistance were Barsoy, Betzes, Boxer, Clayton, Compana, Custer, Hazen, Hudson, Kamiak, Kenate, Keowee, Maury, Norbert, and Vanguard. These cultivars represent a range of types that could be a starting point in breeding for resistance. No resistance was found in the economically valuable six-row spring malting type of the north central states. The two most common wild barleys of the Great Plains, H. jubatum and H. pusillum, were both susceptible to the stripe rust culture used; neither is likely to be a host during the non-crop-growing season.