Mapping of the stem rust resistance gene Pg13 in cultivated oat

Authors: KEBEDE, AIDA - Agriculture And Agri-Food Canada; YIMER, BELAYNEH - Orise Fellow; BEKELE, WUBISHET - Agriculture And Agri-Food Canada; Gordon, Tyler; Bonman, John; Babiker, Ebrahiem; Jin, Yue; Gale, Sam; WIGHT, CHARLENE - Agriculture And Agri-Food Canada; TINKER, NICHOLAS - Agriculture And Agri-Food Canada; MENZIES, JIM - Agriculture And Agri-Food Canada; BEATTIE, AARON - University Of Saskatoon; MITCHELL-FETCH, JENNIFER - Agriculture And Agri-Food Canada; FETCH, THOMAS - Agriculture And Agri-Food Canada; Esvelt Klos, Kathy; MCCARTNEY, CURT - Agriculture And Agri-Food Canada

Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/9/2019
Publication Date: 10/21/2019
Citation: Kebede, A.Z., Yimer, B.A., Bekele, W., Gordon, T.C., Bonman, J.M., Babiker, E.M., Jin, Y., Gale, S.W., Wight, C.P., Tinker, N., Menzies, J., Beattie, A., Mitchell-Fetch, J., Fetch, T., Esvelt Klos, K.L., McCartney, C. 2019. Mapping of the stem rust resistance gene Pg13 in cultivated oat. Journal of Theoretical and Applied Genetics. 133:259-270. https://doi.org/10.1007/s00122-019-03455-5.
DOI: https://doi.org/10.1007/s00122-019-03455-5

Interpretive Summary: Stem rust disease can negatively affect oat yields in the production areas of the United States and Canada. Disease resistance in modern oat varieties is almost entirely due to two genes (Pg2 and Pg13) deployed alone or in combination. Breeding new varieties to have a three-gene combination of stem rust resistance would provide growers with an extra layer of protection against changes to this disease that may happen through chance. In order for such varieties to be developed efficiently and in a timely manner, breeders need to know where each gene lies on the oat genome. They also need reliable molecular genetic markers to identify lines carrying the desired trait without the need for expensive and lengthy testing. This study placed the Pg13 gene onto the oat genome linkage map. Molecular markers were identified that accurately predict which oat lines carry the Pg13 gene. This will enable oat breeders to use marker-assisted selection for Pg13 in their breeding programs.

Technical Abstract: Key message The widely deployed, oat stem rust resistance gene Pg13 was mapped by linkage analysis and association mapping, and KASP markers were developed for marker-assisted selection in breeding programs. Abstract Pg13 is one of the most extensively deployed stem rust resistance genes in North American oat cultivars. Identification of markers tightly linked to this gene will be useful for routine marker-assisted selection, identification of gene pyramids, and retention of the gene in backcrosses and three-way crosses. To this end, high-density linkage maps were constructed in four bi-parental mapping populations using SNP markers identified from 6K oat Infinium iSelect and genotyping-bysequencing platforms. Additionally, genome-wide associations were identified using two sets of association panels consisting of diverse elite oat lines in one set and landrace accessions in the other. The results showed that Pg13 was located at approximately 67.7 cM on linkage group Mrg18 of the consensus genetic map. The gene co-segregated with the 7C-17A translocation breakpoint and with crown rust resistance gene Pc91. Co-segregating markers with the best prediction accuracy were identified at 67.7–68.5 cM on Mrg18. KASP assays were developed for linked SNP loci for use in oat breeding.