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ARS Home » Midwest Area » St. Paul, Minnesota » Cereal Disease Lab » Research » Research Project #440272

Research Project: Detailed Molecular Characterization of Oat Crown Rust Resistance

Location: Cereal Disease Lab

Project Number: 5062-21220-025-015-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Aug 31, 2022
End Date: Aug 30, 2026

The specific objectives of this project are: 1) Detailed characterization of oat genomic regions harboring important crown rust resistance loci; 2) Develop molecular markers for introgression of effective genes into modern cultivars; 3) Develop genetic populations and tools to further dissect critical crown rust resistance genes; and 4) Identify and characterize effector genes from P. coronata.

Oat crown rust fungi (Puccinia coronata) is a highly variable pathogen spread throughout the U.S. This variability leads to constant erosion of effective resistance in the oat crop. This loss of resistance leads to significant losses by the farmers and necessitates development of cultivars with effective resistance. Additionally, successful management strategies for this disease depend on monitoring, collection, virulence phenotyping, and genotypic characterization of the pathogen populations. Rust resistant oat germplasm (wild species and cultivars) are being systematically selected and screened in the buckthorn nursery, where a large and variable source of pathogen is maintained, for new and effective plant resistance genes. Testing with selected isolates of the crown rust pathogen and or mixture of variable population collected from buckthorn, and host genetics studies will identify the rust resistance genes in these germplasm. These genes will then be introgressed into modern cultivars and lines with combinations of rust resistance genes will be selected and released for further use in cultivar development. Additionally, we have initiated studies to further characterize identified resistance genes with molecular markers for introgression and cloning. Rust fungi produce a large arsenal of effector proteins in order to infect and colonize the plant host. Genetic and genomic approaches will be used to identify and characterize effector genes from P. coronata.