|DUNCKEL, SANDRA - Kansas State University
|OLSON, ERIC - Michigan State University
|Rouse, Matthew - Matt
|POLAND, JESSE - Kansas State University
Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/14/2015
Publication Date: 5/13/2015
Publication URL: http://handle.nal.usda.gov/10113/5493340
Citation: Dunckel, S.M., Olson, E.L., Rouse, M.N., Bowden, R.L., Poland, J.A. 2015. Genetic mapping of race-specific stem rust resistance in the synthetic hexaploid W7984 x Opata M85 mapping population. Theoretical and Applied Genetics. 55:1–9. doi: 10.2135/cropsci2014.11.0755.
Interpretive Summary: Stem rust is one of the most potentially destructive diseases of wheat and barley worldwide. Geneticists are constantly looking for new sources of resistance genes to control this disease. Mapping populations are an important genetic resource in wheat for locating genes on chromosomes. One of the well-studied mapping populations is the Synthetic x Opata reference population. Segregating lines from the reference population were screened at the seedling stage and four stem rust resistance genes were identified on chromosome arms 1AS, 2BS, 6AS, and 6AL. Some of the genes appear to be novel and need to be studied further to determine their usefulness for crop improvement.
Technical Abstract: Stem rust (caused by Puccinia graminis f. sp. tritici) has historically caused severe yield losses of wheat (Triticum aestivum) worldwide and has been one of the most feared diseases of wheat and barley (Hordeum vulgare). Stem rust has been controlled successfully through the use of resistant varieties. However, stem rust race Ug99 and its derivatives are virulent to many widely deployed stem rust resistance genes including Sr31. Doubled haploid lines from the Synthetic W7984 x Opata M85 wheat reference population were screened for seedling resistance to P. graminis f. sp. tritici races TRTTF and QTHJC. Infection types were scored 14 days after inoculation according to the Stakman scale. The phenotypic data were adjusted to a 1 to 5 scale and genes for resistance to races TRTTF and QTHJC were localized using Composite Interval Mapping. Major effect QTLs for resistance to stem rust races TRTTF and QTHJC were identified on chromosome arms 1AS, 2BS, 6AS and 6AL. The gene for resistance to both races on 2BS could potentially be a new stem rust resistance gene. The resistance genes on 1AS and 6AL might be other new genes or alleles while the gene on 6AS is likely an Sr8 allele. Future work will determine if the resistance loci on 1AS, 2BS and 6AL are novel. As shown here, the well studied Synthetic x Opata reference population is a valuable source of potentially novel resistance genes for stem rust.