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ARS Home » Pacific West Area » Aberdeen, Idaho » Small Grains and Potato Germplasm Research » Research » Publications at this Location » Publication #432092
Research Project: Enhancing Barley and Oat Productivity, Quality, and Stress Resistance

Location: Small Grains and Potato Germplasm Research

Title: Uncovering the genetic basis of crown rust resistance in a northern-by-southern oat biparental population

Author
item SAPKOTA, SURAJ - Oak Ridge Institute For Science And Education (ORISE)
item FURLAN, FLAVIA - Louisiana State University
item HARRISON, STEPHEN - Louisiana State University
item DEWITT, NOAH - Louisiana State University
item BABAR, MD ALI - University Of Florida
item Yimer, Belayneh
item Chowdhury, Rawnaq
item Esvelt Klos, Kathy

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/28/2026
Publication Date: 6/24/2026
Citation: Sapkota, S., Furlan, F., Harrison, S.A., Dewitt, N., Babar, M., Yimer, B.A., Chowdhury, R.N., Esvelt Klos, K.L. 2026. Uncovering the genetic basis of crown rust resistance in a northern-by-southern oat biparental population . PLOS ONE. https://doi.org/10.1371/journal.pone.0351420.
DOI: https://doi.org/10.1371/journal.pone.0351420

Interpretive Summary: Oat holds an important position in global cereal production, ranking seventh among cereals. Its versatile applications as forage, in the cosmetic industry, and as a valuable component of a healthy diet have contributed to its popularity. Oat production has been impacted by many diseases and crown rust is one of the most important diseases capable of reducing oat yield and quality. Oat breeding programs at the Southeastern USA have selected many crown rust resistant oat breeding lines but the genetic factors governing the resistance remain unknown. To dissect the genetic control of crown rust resistance in a southern oat breeding line LA07065_SBSBSB_32-2, a bi-parental mapping population was developed through a cross between LA07065_SBSBSB_32-2 and CDC Dancer. The parental lines and the population were evaluated for adult plant crown rust resistance under four field environments. Genomic loci influencing crown rust resistance were detected based on the genotype information from 6000 sites across the oat genome. The highly resistant oat lines and genomic loci associated with crown rust resistance in this study may be useful as a tool to develop crown rust resistant oat germplasm.

Technical Abstract: Crown rust, caused by the fungal pathogen Puccinia coronata f. sp. avenae (Pca), is a destructive foliar disease of oat. Use of host resistance is the preferred method of disease management. However, frequent emergence of new Pca races has hindered crown rust management in oat. Identification and deployment of non-race-specific genetic resistance will aid oat breeding efforts to develop germplasm with durable crown rust resistance. To map and characterize crown rust resistance, a recombinant inbred line (RIL) population was developed from a cross between LA07065_SBSBSB_32-2 and CDC Dancer and evaluated for crown rust reaction in four field environments across two years. The RIL population was genotyped using the oat 6K Infinium iSelect single nucleotide polymorphism (SNP) array and a total of 956 polymorphic SNP markers were used to construct the linkage map. Quantitative trait loci (QTL) mapping detected a total of six QTL on chromosomes 2D, 4A, 7A, 7C, and 7D influencing crown rust resistance. Two of these QTL were validated using genotype-phenotype association analysis in an independent set of oat lines. The identified QTL demonstrated additive effects on crown rust resistance within the RIL population. A major QTL on chromosome 7C, QPca-ars-7C, was detected consistently across environments and explained up to 16.54% of the phenotypic variation. Markers linked to QPca-ars-7C, and other QTL detected in this study have the potential to be used in marker-assisted selection for crown rust resistance.