Virulence characterization of Puccinia striiformis f. sp. Tritici collections from China, Italy, Mexico, and Ecuador

Puccinia striiformis f. sp. tritici (Pst) causing stripe rust is one of the most important pathogens on wheat worldwide. The fungus evolves into different virulent races to overcome resistance. In 2014-2017, 443 isolates were recovered from collections of China (141), Italy (133), Mexico (123), and...

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Bibliographic Details
Main Authors: Wang, Meinan, Wan, Anmin, Li, Mingju, Maccaferri, Marco, Figueroa López, Pedro, Barnes, Charles W., Campaña Cruz, Diego Fabricio, Chen, Xianming
Format: Congreso
Language:en
Published: Boston, EE.UU: International Congress of Plant Pathology, 2018 2018
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Online Access:http://repositorio.iniap.gob.ec/handle/41000/5110
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Summary:Puccinia striiformis f. sp. tritici (Pst) causing stripe rust is one of the most important pathogens on wheat worldwide. The fungus evolves into different virulent races to overcome resistance. In 2014-2017, 443 isolates were recovered from collections of China (141), Italy (133), Mexico (123), and Ecuador (46). These isolates were tested with 18 wheat Yr single-gene lines that are used to differentiate Pst races in the U.S. A total of 132 Pst races were detected, including 105 new races. The number of unique races in China, Mexico, Italy, and Ecuador were 54, 25, 24, and 18, respectively. None of the races were shared by more than two countries, but 4 races were shared by China and Italy, 3 by China and Mexico, and 4 by Ecuador and Mexico. The top three predominant races, PSTv-37 (40.7%), PSTv-52 (17.1%), and PSTv- 198 (9.8%), were similar to those identified in the US in 2016. Overall, virulences to Yr43, YrExp2, Yr6, Yr7, and Yr44 were most frequent (81.0-90.3%); those to YrTrl, Yr8, Yr76, Yr27, Yrl7, YrSP, and Yrl were moderate (17.8-59.6%); and those to YrlO, Yr24, and Yr32 were low (0.5-1.1%). None of the races were virulent on Yr5 or Yrl5. Significant variations in frequency were detected for virulences to Yrl (10.6% in Mexico to 85.8% in China); Yrl 7(11.3% in China to 71.4% in Italy); Yr27 (3.0% in Italy to 84.6% in Mexico); and Yr76 (6.5% in Ecuador to 83.0% in China). The information is useful for understanding epidemiology and controlling stripe rust.