Location: Tropical Crops and Germplasm ResearchTitle: Testing the model for a dominant resistance gene expresed on leaves of Phaseolus vulgaris F2 (0313-58 X Rosada Nativa) to the common bacterial blight pathogen, Xanthomonas axonopodis pv. Phaseoli) Author
|Porch, Timothy - Tim|
Submitted to: Bean Improvement Cooperative Annual Report
Publication Type: Research Notes
Publication Acceptance Date: 4/2/2009
Publication Date: 4/15/2009
Citation: Zapata, M., Beaver, J., Porch, T.G. 2009. Testing the model for a dominant resistance gene expresed on leaves of Phaseolus vulgaris F2 (0313-58 X Rosada Nativa) to the common bacterial blight pathogen, Xanthomonas axonopodis pv. Phaseoli. Bean Improvement Cooperative Annual Report. 52:72-73. Interpretive Summary: Common bacterial blight (CBB), an important bacterial disease of common bean, Phaseolus vulgaris, causes signficant disease and reductions in yield in common bean worldwide. Commercial cultivars have inadequate resistance to the bacteria, Xanthomonas axonopodis pv. phaseoli, that causes CBB in bean. In order to improve and breed for resistance to CBB, the genetics of resistance to this important disease need to be better understood. A common bean population was created and inoculated with the two strains of the bacteria to determine the presence of specific genes for resistance. The results with one strain indicate that a single dominant gene conditions resistance to bacterial blight strain 3353 in common bean line 0313-58. This study is the first to show the presence of a specific gene for resistance to Xanthomonas axonopodis in common bean. The selection of common bean cultivars with this gene will provide resistance to CBB strain 3353.
Technical Abstract: The common bean bacterial blight pathogen, Xanthomonas axonopodis pv. phaseoli, is a limiting factor for bean, Phaseolus vulgaris, production worldwide and resistance to the pathogen in commercial varieties is inadequate. To test the hypothesis of the presence of strain specific genes for resistance to common bacterial blight in Phaseolus vulgaris, a population was created between the line 0313-58 and cultivar Rosada Nativa. The bean line, 0313-58, was selected because it shows a differential reaction to Xap strains 3353 and 1934. The reactions of the F2 using Xap 3353 fit a 3R:1S model indicating a dominant gene for bacterial blight resistance. These results represent the first evidence for specific genes for resistance to Xanthomonas axonopodis in common bean. Selection for this gene in breeding programs will provide strain specific resistance to Xap.