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ARS Home » Pacific West Area » Aberdeen, Idaho » Small Grains and Potato Germplasm Research » Research » Publications at this Location » Publication #246425
Title: Identification and Validation of Quantitative Trait Loci for Partial Resistance to Crown Rust in Oat.

Author
item Acevedo, Maricelis
item Jackson, Eric
item CHONG, J - Agriculture And Agri-Food Canada
item Rines, Howard
item HARRISON, S - Louisiana State University
item Bonman, John

Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/21/2010
Publication Date: 5/1/2010
Citation: Acevedo, M., Jackson, E.W., Chong, J., Rines, H.W., Harrison, S., Bonman, J.M. 2010. Identification and Validation of Quantitative Trait Loci for Partial Resistance to Crown Rust in Oat. Phytopathology. 100(5):511-521.

Interpretive Summary: Crown rust is the most important disease of oat worldwide and developing resistant varieties is the best way to control crown rust. Molecular markers associated with resistance allow rapid and convenient selection for resistance. To develop useful markers, we must first ‘validate’ resistance loci through by testing in various environments. The objective of this study was to validate and discover quantitative trait loci (QTL) affecting crown rust resistance in the partially resistant oat line MN841801-1 using conventional and molecular assessments of disease produced in single-race greenhouse inoculations, single-race polycyclic field tests, and under natural infection in disease-conducive environments. We validated the crown rust resistance found at several loci in the oat genome using multi-location trials and new methods to measure the disease resistance. These loci could be valuable in controlling crown rust and we plan to develop genetic markers that can be used to easily introduce them into improved oat cultivars. Controlling crown rust with natural disease resistance will help to boost the competitiveness of the US oat crop.

Technical Abstract: Management of oat crown rust disease with host resistance is challenging because major gene resistance is generally short-lived. Partial resistance in productive oat cultivars could benefit oat growers by providing more durable resistance. The objective of this study was to validate and discover quantitative trait loci (QTL) affecting crown rust resistance in the partially resistant oat line MN841801-1 using conventional and molecular assessments of disease produced in single-race greenhouse inoculations, single-race polycyclic field tests, and under natural infection in disease-conducive environments. Crown rust was assessed on 150 F 6:8 MN841801-1/‘Noble-2’ recombinant inbred lines (RIL). A total of eight QTL associated with MN841801-1 alleles were detected. Of these, seven matched QTL previously identified while a new QTL (Prq8) was detected on linkage group MN13. Four QTL (Prq1a, Prq2, Prq7 and Prq8) were consistently detected and predicative genetic assays for these QTL should be developed for future validation in additional genetic backgrounds.