Location: Small Grains and Potato Germplasm Research
Project Number: 2050-21000-038-032-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2026
End Date: Aug 31, 2027
Objective:
This project will identify, map, and characterize novel genes and QTL conferring resistance to crown rust in oat by integrating phenotypic and genotypic data from bi parental and multi parent mapping populations
Approach:
This project builds on previous work that identified new sources of crown rust resistance in oat germplasm and developed multiple mapping populations to localize the underlying resistance genes and QTL. The mapping resources include two bi-parental populations derived from crosses between the resistant accession PI 177867 and two susceptible cultivars, as well as selected early generation lines from the multi-parent HXS population.
Field-based phenotyping for crown rust resistance will be conducted by the University Cooperator. Disease reactions will be scored under natural infection conditions, and single panicles from a few selected accessions exhibiting resistant to moderately resistant responses will be collected for further analysis. The ARS Principal Investigator will perform genotyping of all mapping populations using appropriate molecular marker platforms.
Phenotypic and genotypic datasets will be integrated to map QTL associated with crown rust resistance and to determine whether the effective genes represent novel resistance sources. Identified resistance loci from PI 177867 and other resistant parents may subsequently be introgressed into elite oat breeding lines to enhance their resistance to Puccinia coronata f. sp. avenae (Pca).
The ARS PI and University Cooperator will jointly evaluate derived populations for both disease resistance and agronomic performance under fall planted and spring planted environments. Collaborative efforts will focus on characterizing and mapping resistance genes to ensure that the resistance deployed in future germplasm releases remains effective against prevailing Pca races. This integrated approach will support the development of oat cultivars with durable, field relevant crown rust resistance.