|Penman, L - WASHINGTON STATE UNIV|
Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: June 1, 2006
Publication Date: July 1, 2006
Citation: Chen, X., Penman, L. 2006. Stripe rust epidemic and races of puccinia striiformis in the united states in 2005. APS Abstracts 96:S23. July 29-Aug 2, 2006, Quebec City, Quebec, Canada. Technical Abstract: Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (PST), occurred in 34 states and caused yield losses of more than 73 million bushels in the U.S. in 2005. Barley stripe rust, caused by P. striiformis f. sp. hordei (PSH), occurred in five states and caused yield losses of 248,600 bushels. A total of 27 PST races and 15 PSH races were identified by testing the isolates on 20 wheat differential genotypes and 12 barley differential genotypes, respectively. Six PST races and two PSH races were first identified in 2005. More than 96% of the PST isolates belonged to the group of races (e.g. PST-78, PST-98, and PST-100) with virulences to Yr8, Yr9, and other resistance genes, which caused widespread stripe rust epidemics in the U.S. from 2000 to 2005. PST-100 (virulent on Lemhi, Heines VII, Produra, Yamhill, Stephens, Lee, Fielder, Express, Yr8-AVS, Yr9-AVS, Clement, and Compair), PST-102 (the same as PST-100 plus virulence on Tres), and PST-115 (the same as PST-102 plus virulence on Paha) were the most predominant races, accounting for 33.4%, 27.0%, and 14.4% of the total PST isolates, respectively. PST-116 (a new race with the same virulence of PST-115 plus virulence on Moro) increased rapidly in the late growing season in the Pacific Northwest. Race PSH-56 (virulent to Topper, Hiproly, Abed Binder 12, and Bancroft) was the most predominant, accounting for 26.7% of the PSH isolates.