Submitted to: International Congress of Plant Pathology Abstracts and Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: February 16, 2008
Publication Date: August 24, 2008
Citation: Chen, X. 2008. Evolution and dynamics of Puccinia striiformis f. sp. tritici races in the U.S. from 2000 to 2006. J. Plant Pathol. 90(S2):83. Technical Abstract: Virulences of the stripe rust pathogen (Puccinia striiformis f. sp. tritici) to resistance genes Yr8 and Yr9 were first detected in the south-central states and California in 2000. This new group of races were represented by races PST-78 with virulence to Lemhi (Yr21), Heines VII (Yr2 and YrHVII), Lee (Yr7, Yr22 and Yr23), Fielder (Yr6 and Yr20), Express (YrExp1 and YrExp2), AVS/6*Yr8 (Yr8), AVS/6*Yr9 (Yr9), Clement (Yr9 and YrCle) and Compair (Yr8 and Yr19) and PST-80 with the virulences of PST-78 plus virulence to Produra (YrPr1 and YrPr2). Since then these races have evolved into more virulent races by combining their virulences with previously existing virulences. The virulences present in new races with combination of the virulences of PST-78 and PST-80 include those to Tres (YrTr1 and YrTr2), Stephens (Yr3a, YrSte and YrSte2), Yamhill (Yr2, Yr4a and YrYam), Chinese 166 (Yr1), Paha (YrPa1, YrPa2 and YrPa3), Moro (Yr10 and YrMor) and Duchamp (Yr3a, YrDru and YrDru2). These new races have become more and more predominant. Race PST-100 with virulences of PST-80 plus virulences to Stephens and Yamhill has replaced PST-78 and PST-80 as the most predominant race throughout the United States since 2003. Races with the Yr1 virulence and those of PST-100 have become predominant in California and races with virulences to Moro and/or Paha in combination of the PST-100 virulences have become predominant in the US Pacific Northwest, which are associated to genes for race-specific resistance deployed in these regions. The race dynamics warrants the use of non-races-specific resistance.