Skip to main content
ARS Home » Pacific West Area » Pullman, Washington » WHGQ » Research » Publications at this Location » Publication #373302
Research Project: Improving Control of Stripe Rusts of Wheat and Barley through Characterization of Pathogen Populations and Enhancement of Host Resistance

Location: Wheat Health, Genetics, and Quality Research

Title: Stripe rust epidemics of wheat and barley and races of Puccinia striiformis identified in the United States in 2019

Author
item WANG, M - Washington State University
item Chen, Xianming

Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2020
Publication Date: N/A
Citation: N/A

Interpretive Summary: In 2019, stripe rust of barley occurred in Idaho, Oregon, and Washington, and stripe rust of wheat occurred in 15 states. To monitor virulence changes of the pathogens, stripe rust samples were tested on 18 wheat and 12 barley differentials to identify races. From 30 isolates obtained from barley stripe rust samples, 9 races were detected including one new race (PSH-116). Races PSH-33 (33.3%) and PSH-116 (26.7%) were the predominant races. From 244 isolates obtained from wheat stripe rust samples, 27 races were identified, including 3 new races (PSTv-323, PSTv-324, and PSTv-325). The top five predominant races were PSTv-37 (43.9%), PSTv-47 (9.4%), PSTv-41 (8.2%), PSTv-322 (6.1%), and PSTv-4 (3.3%). PSTv-37 was detected throughout the country, while PSTv-4, PSTv-41, PSTv-47, and PSTv-322 were mostly in the western U.S. Virulence frequencies were high (70.5 - 90.2%) to resistance genes Yr6, Yr7, Yr8, Yr9, Yr17, Yr27, Yr43, Yr44, YrTr1, and YrExp2; but low to Yr1, Yr10, Yr24, Yr32, YrSP, and Yr76 (7.4% - 36.9%). No virulence was detected to either resistance gene Yr5 or Yr15. The results are useful for breeding resistant varieties and control of stripe rust.

Technical Abstract: In 2019, stripe rust of barley, caused by Puccinia striiformis f. sp. hordei (Psh), occurred in Idaho, Oregon, and Washington, and stripe rust of wheat, caused by P. striiformis f. sp. tritici (Pst), occurred in 15 states. To monitor virulence changes of the pathogens, stripe rust samples were tested on 18 wheat and 12 barley differentials to identify Pst and Psh races, respectively. From 30 Psh isolates, 9 races were detected including one new race, PSH-116 (virulent on differentials Topper, Hiproly, Abed Binder 12, Trumpf, and Bigo). PSH-33 (virulent on Topper and Abed Binder 12) and PSH-116 were the predominant races with frequencies of 33.3% and 26.7%, respectively. From 244 Pst isolates, 27 races were identified, including 3 new races (PSTv-323 virulent to Yr6, Yr7, Yr8, Yr9, Yr17, Yr27, Yr43, Yr44, YrSP, and YrExp2; PSTv-324 virulent to Yr1, Yr6, Yr7, Yr9, Yr27, Yr43, Yr44, YrTr1, YrExp2, and Yr76; and PSTv-325 virulent to Yr1, Yr7, Yr8, Yr9, Yr27, Yr44, YrTr1, YrExp2, and Yr76 among 18 Yr single-gene differentials). The top five predominant races were PSTv-37 (43.9%), PSTv-47 (9.4%), PSTv-41 (8.2%), PSTv-322 (6.1%), and PSTv-4 (3.3%). PSTv-37 was detected throughout the country, while PSTv-4, PSTv-41, PSTv-47, and PSTv-322 were mostly in the western U.S. Virulence frequencies were high (70.5 - 90.2%) to Yr6, Yr7, Yr8, Yr9, Yr17, Yr27, Yr43, Yr44, YrTr1, and YrExp2; but low to Yr1, Yr10, Yr24, Yr32, YrSP, and Yr76 (7.4% - 36.9%). No virulence was detected to either Yr5 or Yr15. The results are useful for breeding resistant cultivars and control of stripe rust.