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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Soybean Genomics & Improvement Laboratory » Research » Research Project #434691

Research Project: Combining Phenotype, Genetics, and Genomics to Develop Common Beans with Resistance to Highly Variable Pathogens

Location: Soybean Genomics & Improvement Laboratory

Project Number: 8042-22000-310-00-D
Project Type: In-House Appropriated

Start Date: May 9, 2018
End Date: May 8, 2023

Objective:
Objective 1: Evaluate diverse common bean accessions, especially in the Andean gene pool, to discover genes and markers linked to these genes that confer resistance to the hyper-variable pathogens that cause rust, anthracnose, angular leaf spot, and other diseases of common bean. [NP301, C1, PS1A and PS1B] Objective 2: Use phenotypic approaches and molecular markers to develop common beans combining Andean and Mesoamerican gene pools to confer broad resistance to highly variable pathogens of common bean. [NP301, C1, PS1A and PS1B] Objective 3: Improve knowledge of virulence, genetic, and genomic diversity of the hyper-variable pathogens that cause common bean diseases. [NP301, C1, PS1A and PS1B; C3, PS3A]

Approach:
The major objective of this project is to concurrently broaden the genetic base of common bean to decrease the vulnerability of this crop to the highly variable pathogens that cause the rust, anthracnose, and angular leaf spot diseases. This project is based on genetic solutions that use conventional (phenotype and genetics) and new (genomics) technologies to develop common bean cultivars with broad and durable resistance to these three pathogens. In objective 1, to discover new disease resistance genes, Andean and Mesoamerican common bean accessions will be inoculated under greenhouse conditions with numerous races of the three pathogens. Races known for their virulence will be used in these inoculations. Bean accessions with resistance to most races of three pathogens will be crossed with susceptible cultivars to characterize the new disease resistance genes. To develop DNA markers tagging the newly discovered resistance genes, DNA from the parents used in crosses and from segregating populations will genotyped with the BARCBEAD6K BeadChip. To validate the usefulness of the newly developed molecular markers, phenotypic and molecular approaches will be used. In objective 2, molecular methodologies will be used to accelerate the development of cultivars from various common bean market classes that combine sets of Andean and Mesoamerican genes and broad resistance. Multiple crosses will be performed and multiple races of these pathogens will be used to confirm the spectrum of resistance of the cultivars. In objective 3, to broaden the existing knowledge of the virulence, genetic, and genomic diversity of three mentioned pathogens, DNA from Mesoamerican and Andean strains with known virulence profiles will be used for sequencing and to obtain draft genomes of these pathogens. The sequences will be used to identify DNA markers that may tag specific strains of these pathogens. These markers can be used in genetic diversity studies, and can also be used to improve our understanding of the mechanisms that drive virulence changes in these pathogens.