Authors
D.
Sharma-Poudyal
,
Department of Plant Pathology, Washington State University, Pullman, WA, USA 99164-6430
;
X. M.
Chen
,
United States Department of Agriculture–Agricultural Research Service, Wheat Genetics, Quality, Physiology, and Disease Research Unit and Department of Plant Pathology, Washington State University, Pullman
;
A. M.
Wan
,
Department of Plant Pathology, Washington State University, Pullman
;
G. M.
Zhan
and
Z. S.
Kang
,
State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
;
S. Q.
Cao
and
S. L.
Jin
,
Institute of Plant Protection, Gansu Academy of Agricultural Sciences, Lanzhou, Gansu, China
;
A.
Morgounov
and
B.
Akin
,
International Winter Wheat Improvement Program, (ICARDA-CIMMYT) Wheat Improvement Program, Ankara, Turkey
;
Z.
Mert
,
Central Research Institute for Field Crops, Ankara, Turkey
;
S. J. A.
Shah
,
Nuclear Institute for Food and Agriculture, Peshawar, Pakistan
;
H.
Bux
,
Institute of Plant Sciences, University of Sindh Jamshoro, Pakistan
;
M.
Ashraf
,
NUST Centre of Virology and Immunology, National University of Science and Technology (NUST), Islamabad, Pakistan
;
R. C.
Sharma
,
ICARDA-Central Asia and the Caucasus Regional Program, 4564, Tashkent, Uzbekistan
;
R.
Madariaga
,
National Institute of Agricultural Research, Chillan, Chile
;
K. D.
Puri
,
Department of Plant Pathology, North Dakota State University, Fargo 58108-6050
;
C.
Wellings
,
Plant Breeding Institute, University of Sydney, Camden, NSW, Australia
;
K. Q.
Xi
,
Field Crop Development Centre, Alberta Agriculture and Food, Lacombe, Canada
;
R.
Wanyera
,
Kenyan Agricultural Research Institute, Njoro, Kenya
;
K.
Manninger
,
Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest
;
M. I.
Ganzález
,
Limagrain Ibérica, Marchena, Spain
;
M.
Koyda
and
S.
Sanin
,
All-Russian Research Institute of Phytopathology, Bolshie Vyazemy, Russia
; and
L. J.
Patzek
,
Department of Crop and Soil Sciences, Washington State University, NWREC, Mount Vernon
Abstract
Wheat stripe rust (yellow rust [Yr]), caused by Puccinia striiformis f. sp. tritici, is an economically important disease of wheat worldwide. Virulence information on P. striiformis f. sp. tritici populations is important to implement effective disease control with resistant cultivars. In total, 235 P. striiformis f. sp. tritici isolates from Algeria, Australia, Canada, Chile, China, Hungary, Kenya, Nepal, Pakistan, Russia, Spain, Turkey, and Uzbekistan were tested on 20 single Yr-gene lines and the 20 wheat genotypes that are used to differentiate P. striiformis f. sp. tritici races in the United States. The 235 isolates were identified as 129 virulence patterns on the single-gene lines and 169 virulence patterns on the U.S. differentials. Virulences to YrA, Yr2, Yr6, Yr7, Yr8, Yr9, Yr17, Yr25, YrUkn, Yr28, Yr31, YrExp2, Lemhi (Yr21), Paha (YrPa1, YrPa2, YrPa3), Druchamp (Yr3a, YrD, YrDru), Produra (YrPr1, YrPr2), Stephens (Yr3a, YrS, YrSte), Lee (Yr7, Yr22, Yr23), Fielder (Yr6, Yr20), Tyee (YrTye), Tres (YrTr1, YrTr2), Express (YrExp1, YrExp2), Clement (Yr9, YrCle), and Compair (Yr8, Yr19) were detected in all countries. At least 80% of the isolates were virulent on YrA, Yr2, Yr6, Yr7, Yr8, Yr17, YrUkn, Yr31, YrExp2, Yr21, Stephens (Yr3a, YrS, YrSte), Lee (Yr7, Yr22, Yr23), and Fielder (Yr6, Yr20). Virulences to Yr1, Yr9, Yr25, Yr27, Yr28, Heines VII (Yr2, YrHVII), Paha (YrPa1, YrPa2, YrPa3), Druchamp (Yr3a, YrD, YrDru), Produra (YrPr1, YrPr2), Yamhill (Yr2, Yr4a, YrYam), Tyee (YrTye), Tres (YrTr1, YrTr2), Hyak (Yr17, YrTye), Express (YrExp1, YrExp2), Clement (Yr9, YrCle), and Compair (Yr8, Yr19) were moderately frequent (>20 to <80%). Virulence to Yr10, Yr24, Yr32, YrSP, and Moro (Yr10, YrMor) was low (≤20%). Virulence to Moro was absent in Algeria, Australia, Canada, Kenya, Russia, Spain, Turkey, and China, but 5% of the Chinese isolates were virulent to Yr10. None of the isolates from Algeria, Canada, China, Kenya, Russia, and Spain was virulent to Yr24; none of the isolates from Algeria, Australia, Canada, Nepal, Russia, and Spain was virulent to Yr32; none of the isolates from Australia, Canada, Chile, Hungary, Kenya, Kenya, Nepal, Pakistan, Russia, and Spain was virulent to YrSP; and none of the isolates from any country was virulent to Yr5 and Yr15. Although the frequencies of virulence factors were different, most of the P. striiformis f. sp. tritici isolates from these countries shared common virulence factors. The virulences and their frequencies and distributions should be useful in breeding stripe-rust-resistant wheat cultivars and understanding the pathogen migration and evolution.
