Journal article
Wheat Stripe Rust Epidemics and Races of Puccinia striiformis f. sp. tritici in the United States in 2000
Plant disease, Vol.86(1), pp.39-46
01/2002
Handle:
https://hdl.handle.net/2376/105980
PMID: 30822996
Abstract
Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici, is most destructive in the western United States and has become increasingly important in the south-central states. The disease has been monitored by collaborators through field surveys and in disease nurseries throughout the United States. In the year 2000, stripe rust occurred in more than 20 states throughout the country, which was the most widespread occurrence in recorded history. Although fungicide applications in many states reduced yield losses, the disease caused multimillion dollar losses in the United States, especially in Arkansas and California. One of the prevalent cultivars, RSI 5, had a yield loss of about 50% in the Sacramento-San Joaquin Delta region of California. In the Pacific Northwest, wheat losses due to stripe rust were minimal because cultivars with durable resistance were widely grown and the weather in May 2000 was not favorable for the disease. To identify races of the pathogen, stripe rust collections from 20 states across the United States were analyzed on 20 wheat differential cultivars, including Clement (Yr9, YrCle), Compair (Yr8, Yr19), and the Yr8 and Yr9 near-isogenic lines. In 2000, 21 previously identified races and 21 new races were identified. Of the 21 new races, 8 were pathotypes with combinations of virulences previously known to exist in the United States, and 13 had virulences to one or more of the lines Yr8, Yr9, Clement, or Compair. This is the first report of virulence to Yr8 and Yr9 in the United States. Most of the new races were also virulent on Express. Races that are virulent on Express have been identified in California since 1998. The races virulent on Yr8, Yr9, and Express were widely distributed in California and states east of the Rocky Mountains in 2000. The epidemic in 2000 demonstrates that increased efforts to breed for stripe rust resistance are needed in California, the south-central states, and some other states in the Great Plains. Diversification of resistance genes and use of durable resistance should prevent large-scale and severe epidemics.
Wheat stripe rust was widespread in the United States in 2000, and caused multimillion dollar losses, especially in Arkansas and California. The epidemics in the south-central and southwestern states were caused by weather conditions favorable for disease and by a group of new races of the pathogen. Yield losses caused by stripe rust in the Pacific Northwest were minimal because resistant cultivars were grown. Stripe rust samples collected from 20 states throughout the United States were tested on a set of wheat cultivars that are used to differentiate pathotypes (races) of the stripe rust pathogen. In addition to 21 previously existing races, 21 new races were detected in 2000. Thirteen of the new races were able to infect wheat cultivars that have genes for resistance to all races of the pathogen identified prior to 2000 in the United States. This group of races was widespread in California and regions east of the Rocky Mountains. The information on the 2000 epidemic, new races of Puccinia striiformis f. sp. tritici, and the distribution of races should be useful for understanding and preventing stripe rust epidemics.
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Details
- Title
- Wheat Stripe Rust Epidemics and Races of Puccinia striiformis f. sp. tritici in the United States in 2000
- Creators
- Xianming Chen - USDA-ARS, Wheat Genetics, Physiology, Quality, and Disease Research Unit, and Department of Plant Pathology, Washington State University, Pullman 99164-6430Mary Moore - Department of Plant Pathology, Washington State UniversityEugene A Milus - Department of Plant Pathology, University of Arkansas, Fayetteville 72701David L Long - USDA-ARS, Cereal Disease Laboratory, University of Minnesota, St. Paul 55108-1050Roland F Line - Department of Plant Pathology, Washington State UniversityDavid Marshall - Research and Extension Center, Texas A&M University, Dallas 75252-6599Lee Jackson - Department of Agronomy and Range Sciences, University of California, Davis 95616-8515
- Publication Details
- Plant disease, Vol.86(1), pp.39-46
- Academic Unit
- Plant Pathology, Department of
- Identifiers
- 99900547352201842
- Language
- English
- Resource Type
- Journal article