Submitted to: National American Phytopathology Meetings
Publication Type: Abstract only
Publication Acceptance Date: 3/10/2004
Publication Date: 7/1/2004
Citation: Chen, X., Moore, M.K., Wood, D.A. 2004. Stripe rust epidemics and races of puccinia striiformis in the united states in 2003. National American Phytopathology Meetings. Phytopathology. 94(6):S18. Interpretive Summary:
Technical Abstract: In the US in 2003, stripe rust of wheat, caused by Puccinia striiformis f. sp. tritici (PST), occurred in 25 states, reduced yield by 88.9 million bushels, and cost multimillion dollars for application of fungicides. Stripe rust of barley, caused by P. striiformis f. sp. hordei (PSH), occurred in California and the Pacific Northwest and reduced yield by 150,000 bushels. Without resistant cultivars, losses of wheat and barley would have been much greater. More than 400 wheat stripe rust samples from the 25 states were tested on 20 wheat genotypes used to differentiate PST races, and 30 barley stripe rust samples from California, Idaho, Oregon, and Washington were tested on 12 barley genotypes used to differentiate PSH races. Of 35 PST races detected, 10 have been identified as new races. Races PST-98 (virulent on Lemhi, Heines VII, Produra, Stephens, Lee, Fielder, Express, Yr8, Yr9, Clement, and Compair) and PST-100 with the same virulences as PST-98 plus virulence on Yamhill were the most common, each with a 30% frequency. Races with common virulences on Lemhi, Lee, Fielder, Express, Yr8, Yr9, Clement, and Compair accounted for more than 90% of the PST samples. Of nine PSH races detected, two were new. PSH-54 (virulent on Topper, Abed Binder 12, Trumpf, and Bancroft), PSH-48 (only virulent on Topper), and PSH-56 (virulent on Topper, Hiproly, Abed Binder 12, Trumpf, and Bancroft) accounted for 26, 22, and 22%, respectively, of the PSH samples. PST races with more virulences were more common, while PSH races with fewer virulences were more common.