DEVELOP STRESS-RESISTANT DRY BEAN GERMPLASM AND SUSTAINABLE PEST MANAGEMENT STRATEGIES FOR EDIBLE LEGUMES
Location: Vegetable and Forage Crops Production Research
Title: Genetic characterization and molecular mapping pse-2 gene for resistance to halo blight in common bean
| Fourie, Deidre - |
| Wagner, Jennifer |
| Larsen, Richard |
| Chavarro, Carolina - |
| Blair, Matthew - |
| Gepts, Paul - |
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 15, 2011
Publication Date: November 1, 2011
Citation: Miklas, P.N., Fourie, D., Wagner, J.J., Larsen, R.C., Chavarro, C., Blair, M., Gepts, P. 2011. Genetic characterization and molecular mapping pse-2 gene for resistance to halo blight in common bean. Crop Science. 51:2439-2448.
Interpretive Summary: Halo bacterial blight is a serious disease limiting bean production worldwide. Genetic resistance in the host is effective for controlling the disease but is not fully understood. We identified a robust gene Pse-2 with broad effect against 7 races of the pathogen. Pse-2 appears to be the most useful gene identified to date for global deployment by breeders to combat this pathogen. This gene was tagged with a molecular marker to simplify breeding for halo blight resistance via marker-assisted selection. It is expected that breeders worldwide will use the marker and gene to breed resistant culitvars for control of this problematic disease.
Pseudomonas syringae pv. phaseolicola (Psp) causes ‘Halo Blight’, which is a serious bacterial disease of common bean (Phaseolus vulgaris L.). Several R genes have been discovered in host differential cultivar ZAA 12. Our objectives were to further characterize and enable marker-assisted selection (MAS) of the Pse-2 gene in ZAA 12 purported to have broad effect against multiple Psp races. – A recombinant inbred population, ZAA 12/Canadian Wonder, was challenged by the halo blight pathogen differential set consisting of nine Psp races. The resistance conferred by Pse-2 to Races 2, 3, 4, 5, 7, 8, and 9 expanded the effect known for this gene from three to seven races. Segregation in F2 populations confirmed dominant inheritance for Pse-2 against all races except Race 8. Resistance to Race 8 was recessively inherited and most closely fit a 7 resistant to 9 susceptible segregation ratio in the F2 generation. Perhaps other genes are segregating which modify the effect of Pse-2 against Race 8. A SCAR marker tightly linked with Pse-2 was