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ARS Home » Pacific West Area » Pullman, Washington » WHGQ » Research » Publications at this Location » Publication #333840
Title: Barley stripe rust resistance QTL identified in facultative winter 6-rowed malt barley breeding programs by genome-wide association studies

Author
item BELCHER, ARABY - Oregon State University
item CUESTA-MARCOS, ALFONSO - Seminis Vegetable Seeds, Inc
item SMITH, KEVIN - University Of Minnesota
item MUNDT, CHRISTOPHER - Oregon State University
item Chen, Xianming
item HAYES, PATRICK - Oregon State University

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/30/2017
Publication Date: 1/15/2018
Citation: Belcher, A.R., Cuesta-Marcos, A., Smith, K.P., Mundt, C.C., Chen, X., Hayes, P.M. 2018. Barley stripe rust resistance QTL identified in facultative winter 6-rowed malt barley breeding programs by genome-wide association studies. Crop Science. 58(1):103-119.

Interpretive Summary: Malt barley is a valuable crop. Barley stripe rust (BSR) can drastically reduce grain yield and quality, and climate change is expected to exacerbate our ability to predict and manage BSR epidemics. Resistant varieties are the most sustainable defense against BSR, especially varieties with pyramids of quantitative disease resistance genes. The Oregon State University (OSU) barley breeding program has been selecting for BSR resistance for decades. We wanted to determine the number and effects of the loci underlying that resistance, as well as whether they were quantitative disease resistance or race-specific qualitative resistance, with the former presumably more durable. To test this, we used BSR resistance quantitative trait locus (QTL) mapping via genome-wide association studies in adult-plant field trials (three years, one location) and race-specific seedling greenhouse trials (five races) with a panel composed of 300 lines that represent the OSU and University of Minnesota facultative winter 6-rowed malt barley breeding programs. The panel was developed as part of the Triticeae Coordinated Agricultural Project but was not developed specifically for BSR resistance. In total, we detected three race-specific QTL, one also effective in the field, and fourteen additional adult-plant field QTL. At least five QTL are novel. The resistance QTL, associated markers, and barley lines with the QTL and markers identified in this study are useful for developing stripe rust resistant barley varieties.

Technical Abstract: Malt barley is a valuable crop. Barley stripe rust (BSR, incited by Puccinia striiformis f. sp. hordei) can drastically reduce grain yield and quality, and climate change is expected to exacerbate our ability to predict and manage BSR epidemics. Resistant varieties are the most sustainable defense against BSR, especially varieties with pyramids of quantitative disease resistance (QDR) genes. The Oregon State University (OSU) barley breeding program has been selecting for BSR resistance for decades. We wanted to determine the number and effects of the loci underlying that resistance, as well as whether they were QDR or race-specific qualitative loci, with the former presumably more durable. To test this, we used BSR resistance QTL mapping via genome-wide association studies (GWAS) in adult-plant field trials (three years, one location) and race-specific seedling greenhouse trials (five races) with the FAC-WIN6: a GWAS panel composed of 300 lines that represent the OSU and University of Minnesota facultative winter 6-rowed malt barley breeding programs. The FACWIN-6 was developed as part of the Triticeae Coordinated Agricultural Project but was not developed specifically for BSR resistance. We suspected its BSR resistance distributions might align with the major population structure patterns in ways that would be difficult to account for with a GWAS model alone. Therefore, based on post-analysis diagnostics, we report a qualitative confidence level for each QTL. In total, we detected three race-specific QTL, one also effective in the field, and fourteen additional adult-plant field QTL. At least five QTL are novel.