ARS | Publication request: Races of Puccinia striiformis f. sp. hordei in the United States from 2004 to 2007

Submitted to: Barley Newsletter
Publication Type: Research Notes
Publication Acceptance Date: October 1, 2008
Publication Date: December 1, 2008
Repository URL: http://wheat.pw.usda.gov/ggpages/BarleyNewsletter/51/WABNL51.htm
Citation: Chen, X. 2008. Races of Puccinia striiformis f. sp. hordei in the United States from 2004 to 2007. Barley Newsletter 51:WABNL51.

Interpretive Summary: Virulences of the barley stripe rust pathogen have been studied since the pathogen was first detected in southern Texas in 1991. Races of the pathogen are determined based on virulence and avirulence patterns of stripe rust samples on a set of barley differential genotypes. Races and their frequencies in the U.S. were previously reported up to 2003. This newsletter reports races and their frequencies and distributions from 2004 to 2007. So far, a total of 81 barley stripe rust races have been identified in the U.S since 1991. From 2004-2007, a total of 128 isolates were tested and 30 races were detected. The results indicate a great diversity of races in the stripe rust population. The most predominant race was PSH-71, accounting for 22% of the isolates. The race is virulent on 9 of the 12 barley differential genotypes. This information is useful for selecting effective resistance genes to use in developing resistant barley cultivars.

Technical Abstract: Virulences of Puccinia striiformis Westend. f. sp. hordei (PSH) Eriks., the causal agent of stripe rust of barley, have been studied since the pathogen was first detected in southern Texas in 1991. Races of the pathogen are determined based on virulence and avirulence patterns of stripe rust samples on a set of barley differential genotypes (Chen et al. 1995; Chen 2004, 2007). Chen (2007) reported a total of 74 races that was identified from 1992 to 2005. Data on frequency and distribution of PSH races were reported up to 2004 (Chen et al. 1995; Line and Chen 1996, 1999; Chen 2004). This newsletter reports PSH races and their frequencies and distributions from 2004 to 2007.