Project Number: 8042-22000-328-000-D
Project Type: In-House Appropriated
Start Date: May 9, 2023
End Date: May 8, 2028
Objective 1. Conduct research to identify novel disease resistance genes and use them through introgression into existing varieties, to expand the genetic base of common bean. Objective 2. Conduct research to develop and release common bean germplasm and/or cultivars with durable resistance to hyper-virulent pathogens, with emphasis on anthracnose and rust diseases. Objective 3. Conduct research using next generation sequencing to characterize the diversity of common bean pathogens that regularly produce new virulent strains.
For Objective 1, to identify genes conferring resistance to rust, anthracnose, and angular leaf spot diseases, diversity panels of common bean cultivars including accessions from common bean core collection, wild germplasm of the common bean and related species, i.e., tepary bean (Phaseolus acutifolius), as well as common bean control cultivars with known rust resistance genes will be evaluated by inoculation with different races of the pathogens. Molecular markers associated with previously reported resistant genes will be used to determine whether the identified source of resistance is novel or broadly resistant to the pathogen's races. Markers tagging the newly discovered resistance genes will be developed. The new sources of broad resistance will be crossed with desirable susceptible common beans to study the inheritance of resistance based on the resistance segregation patterns in the F1, F2 and F2-derived progeny. For Objective 2, newly identified disease resistance genes from Objective 1will be used to develop new common bean germplasm lines and cultivars with broad resistance to highly virulence variable rust and anthracnose pathogens of common bean. Previous research from this project demonstrated that combining Middle American and Andean rust resistance genes into a single common bean cultivars results in a broad resistance to all known races of the hyper-virulent rust pathogen. Crosses will be made between common bean varieties that contain the newly identified disease resistance genes to develop common bean germplasm lines that contain novel Andean and Mesoamerican multiple disease resistance genes. Molecular markers will be used to accelerate cultivar development in collaboration with breeders. Seeds of broadly resistant germplasm lines and varieties will be distributed to collaborators for evaluation under local field conditions. For Objective 3, isolates and races of rust, anthracnose, and angular leaf pathogens will be collected from infected common bean plants. Genetic diversity of the isolates will be studied using the approach that combines traditional race characterization and next-generation sequencing. Molecular markers that will enable the identification of specific races of the bean pathogens will be developed. These markers will also be used to monitor pathogen race presence in different bean production areas of the US and other countries.