WASHINGTON, June 8 (UPI) — The U.S. Department of Agriculture says new cultivars of a common bean might defend the legume against the fungal disease common bean rust.
The new cultivars were developed by the USDA’s Agricultural Research Service and university scientists. Talo Pastor-Corrales, an ARS plant pathologist in Beltsville, Md., said the new cultivars possess two or more genes for resistance to the rust fungi. Most of the cultivars also harbor Ur-11, which is considered the most effective rust-resistance gene in the world.
Pastor-Corrales and his colleagues at the University of Nebraska and Colorado State University said they used the multi-gene strategy in response to the high diversity of strains of the bean rust pathogen.
The researchers said virulent new races of rust have recently overcome the Ur-3 resistance gene in Michigan and North Dakota. Until that occurred, the Ur-3 gene had been very effective in controlling rust in the United States. Now scientists fear Ur-3-protected varieties are succumbing to the disease and there’s concern the new races will spread to other Northern Plains states where common beans are grown, such as Colorado and Nebraska.
The research, along with similar efforts to protect other legume crops, are reported in the May/June issue of Agricultural Research magazine, which is also available online at http://www.ars.usda.gov/is/AR/archive/may10/bean0510.htm.
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