QTL analysis of adult plant resistance to stripe rust in a winter wheat recombinant inbred population

Authors: BRANDT, KALI - University Of Oregon; Chen, Xianming; TABIMA, J - University Of Oregon; See, Deven; ZEMETRA, R - University Of Oregon

Submitted to: Plants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/15/2021
Publication Date: 3/18/2021
Citation: Brandt, K.M., Chen, X., Tabima, J.F., See, D.R., Zemetra, R.S. 2021. QTL analysis of adult plant resistance to stripe rust in a winter wheat recombinant inbred population. Plants. 10(3). Article 572. https://doi.org/10.3390/plants10030572.
DOI: https://doi.org/10.3390/plants10030572

Interpretive Summary: Stripe rust is a worldwide disease of wheat that causes devastating crop losses. Resistant cultivars have been developed over the last 40 years that have significantly reduced the economic impact of the disease on growers, but in heavy infection years it is mostly controlled through the intensive application of fungicides. The Pacific Northwest (PNW) of the United States has an ideal climate for stripe rust and also has one of the most diverse race compositions in the country. This has resulted in many waves of epidemics that have overcome most of the resistance genes traditionally used in elite germplasm. The best way to prevent high yield losses, reduce production costs to growers, and reduce the heavy application of fungicides is to pyramid multiple stripe rust resistance genes into new cultivars. Using genotyping by sequencing, we identified 458,150 high quality variant positions in a recombinant inbred line population of 196 individuals derived from a wheat cross between Skiles, an extremely resistant winter wheat variety, and Goetze, a moderately to highly susceptible winter wheat variety. A subsequent genome wide association study identified two quantitative trait loci (QTL) on chromosomes 3B and 3D within the predicted locations of stripe rust resistance genes. Resistance QTL, when combined together, conferred extremely high levels of stripe rust resistance above the level of Skiles in some locations, indicating that these QTL would be important additions to any future breeding efforts of PNW winter wheat varieties.

Technical Abstract: Background. Stripe rust, caused by the basidiomycete fungus Puccinia striiformis f. sp. tritici, is a worldwide disease of wheat that causes devastating crop losses. Resistant cultivars have been developed over the last 40 years that have significantly reduced the economic impact of the disease on growers, but in heavy infection years it is mostly controlled through the intensive application of fungicides. The Pacific Northwest of the United States has an ideal climate for stripe rust and also has one of the most diverse race compositions in the country. This has resulted in many waves of epidemics that have overcome most of the resistance genes traditionally used in elite germplasm. The best way to prevent high yield losses, reduce production costs to growers, and reduce the heavy application of fungicides is to pyramid multiple stripe rust resistance genes into new cultivars. Results. Using genotyping by sequencing, we identified 458,150 high quality variant positions in a recombinant inbred line population of 196 individuals derived from a cross between Skiles, an extremely resistant winter wheat variety, and Goetze, a moderately to highly susceptible winter wheat variety, both developed at Oregon State University. A subsequent genome wide association study identified two quantitative trait loci (QTL) on chromosomes 3B and 3D within the predicted locations of stripe rust resistance genes. Conclusions. Resistance QTL, when combined together, conferred extremely high levels of stripe rust resistance above the level of Skiles in some locations, indicating that these QTL would be important additions to any future breeding efforts of Pacific Northwest winter wheat varieties.