|Pastor Corrales, Marcial - Talo|
Submitted to: Bean Improvement Cooperative Annual Report
Publication Type: Trade Journal
Publication Acceptance Date: 4/1/2011
Publication Date: 6/1/2011
Citation: Pastor Corrales, M.A., Osorno, J., Markell, S., Goswani, R. 2011. Identifying Plants of Stampede Pinto Bean with Resistance to New races of Rust Pathogen. Bean Improvement Cooperative Annual Report. p.126-127. Interpretive Summary:
Technical Abstract: The rust disease of dry beans is caused by a hyper-variable fungus that continually produces new virulent strains. Two new strains, known as races, emerged in Michigan and North Dakota in 2007 and 2008, respectively, which surmounted the resistance of a widely used rust-resistance gene known as Ur-3. This gene is present in many dry bean varieties that previously had been rust resistant. Among the susceptible varieties was the recently released pinto bean Stampede. The ARS-Beltsville bean known as BelDakMi-RMR-14, which is one of the parents of Stampede, was resistant to the two new races. This bean has three rust-resistant genes (Ur-3, Ur-6, and Ur-11). In the process of evaluating dozens of Stampede plants, we discovered some Stampede plants with resistance to both new races. To determine their rust resistance genes, we inoculated these plants with eight races of the rust pathogen that are used to reliably identify the Ur-3, Ur-6, and Ur-11 rust resistance genes alone or in combination. Many of the resistant Stampede plants had two genes (Ur-3 and Ur-11) while a few had three genes (Ur-3, Ur-6, and Ur-11). These results permitted the rapid identification of rust resistant Stampede plants with two and three rust resistance genes. Seed of them had been increased for distribution to bean growers for the control of the new races of the bean rust pathogen, particularly in North Dakota, where most pinto dry beans are produced in the U.S.