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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Cereal Crops Research » Research » Publications at this Location » Publication #324874
Title: Genome-wide association mapping of leaf rust response in a durum wheat worldwide germplasm collection

Author
item AOUN, MERIEM - North Dakota State University
item BREILAND, MATTHEW - North Dakota State University
item TURNER, M - University Of Minnesota
item LOLADZE, ALEXANDER - International Maize & Wheat Improvement Center (CIMMYT)
item Chao, Shiaoman
item Xu, Steven
item AMMAR, KARIM - International Maize & Wheat Improvement Center (CIMMYT)
item ANDERSON, JAMES - University Of Minnesota
item Kolmer, James
item ACEVEDO, MARICELIS - North Dakota State University

Submitted to: The Plant Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/23/2016
Publication Date: 10/6/2016
Publication URL: https://handle.nal.usda.gov/10113/63342
Citation: Aoun, M., Breiland, M., Turner, M.K., Loladze, A., Chao, S., Xu, S.S., Ammar, K., Anderson, J.A., Kolmer, J.A., Acevedo, M. 2016. Genome-wide association mapping of leaf rust response in a durum wheat worldwide germplasm collection. The Plant Genome. 9(3). doi:10.3835/plantgenome2016.01.0008.

Interpretive Summary: Leaf rust caused by a fungal pathogen is increasingly impacting durum wheat production with the recent appearance of races with virulence to widely grown cultivars in many durum producing areas worldwide. A highly virulent race on durum wheat was recently collected in Kansas. This race may spread to the Northern Great Plains region where most of the U.S. durum wheat is produced. The objective of this study was to evaluate a set of 496 worldwide durum germplasm deposited at USDA National Small Grain Collection in Aberdeen, Idaho, and to identify sources of resistance to several races from the U.S. and Mexico. Genetic analysis was performed and ten germplasm were found to be resistant under all the growth conditions investigated. The current study also identified a total of 20 previously uncharacterized gene regions on the chromosomes associated with resistant response to the pathogens in durum wheat. The discovery of these gene regions is a significant step in identifying useful sources of resistance that can be used to broaden relatively narrow leaf rust resistance spectrum in durum wheat germplasm.

Technical Abstract: Leaf rust (caused by Puccinia triticina Eriks.) is increasingly impacting durum wheat production with the recent appearance of races with virulence to widely grown cultivars in many durum producing areas worldwide. A highly virulent P. triticina race on durum wheat was recently collected in Kansas. This race may spread to Northern Great Plains, where most of the U.S. durum wheat is produced. The objective of this study was to identify sources of resistance to several races from USA and Mexico at seedling stage in the greenhouse and at adult stage in field experiments. Genome wide association analysis was used to identify SNP markers associated with leaf rust response in a worldwide durum wheat collection of 496 accessions. Ten accessions comprised of six landraces, two breeding lines, and two cultivars were resistant across all experiments. Association mapping revealed 88 significant SNPs, associated with leaf rust response. Of these 88 SNPs, 33 were located on chromosomes 2A and 2B, and 55 were distributed across all other chromosomes except for 1B and 7B. Twenty markers were associated with leaf rust response at seedling stage, while 68 markers were associated with leaf rust response at adult plant stage. The current study identified a total of 20 previously uncharacterized loci associated with leaf rust response in durum wheat. The discovery of these loci through association mapping is a significant step in identifying useful sources of resistance that can be used to broaden relatively narrow leaf rust resistance spectrum in durum wheat germplasm.