|Penman, L - WASHINGTON STATE UNIV|
Submitted to: National American Phytopathology Meetings
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 2005
Publication Date: June 1, 2005
Citation: Chen, X., Penman, L. 2005. Stripe rust epidemic and races of puccinia striiformis in the united states in 2004. National American Phytopathology Meetings. Phytopathology 95:S19. Technical Abstract: Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (PST), occurred in 27 states and caused a yield loss of 12,229,500 bushels in the U.S. in 2004. Barley stripe rust, caused by P. striiformis f. sp. hordei (PSH), occurred in four states and caused a yield loss of 63,000 bushels. From 313 stripe rust samples, 28 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 three PSH races were new. More than 90% 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 2004. Five of the six new races belonged to this group. Some of the new races had additional virulence to Moro (Yr10 and YrMor) or Paha (YrPa1, YrPa2, and YrPa3), rendering the resistance genes no longer effective against the race group. Race PST-100 (virulent on Lemhi, Heines VII, Produra, Yamhill, Stephens, Lee, Fielder, Express, Yr8-AVS, Yr9-AVS, Clement, and Compair) was the most predominant, accounting for 50% of the PST isolates. Race PSH-71 (virulent to Topper, Emir, Hiproly, Varunda, Abed Binder 12, Trumpf, Mazurk, Bigo, and Bancroft) was the most predominant, accounting for 33% of the PSH isolates.