title: Genetic mapping of SrCad and SNP marker development for marker-assisted selection of Ug99 stem rust resistance in wheat.
abstract: New SNP markers that can be used for marker-assisted selection and map-based cloning saturate the chromosome region carrying SrCad , a wheat gene that confers resistance to Ug99 stem rust. Wheat stem rust, caused by Puccinia graminis f. sp. tritici, is a devastating disease of wheat worldwide. Development of cultivars with effective resistance has been the primary means to control this disease, but the appearance of new virulent strains such as Ug99 has rendered most wheat varieties vulnerable. The stem rust resistance gene SrCad located on chromosome arm 6DS has provided excellent resistance to various strains of Ug99 in field nurseries conducted in Njoro, Kenya since 2005. Three genetic populations were used to identify SNP markers closely linked to the SrCad locus. Of 220 SNP markers evaluated, 27 were found to be located within a 2 cM region surrounding SrCad. The diagnostic potential of these SNPs was evaluated in a diverse set of 50 wheat lines that were primarily of Canadian origin with known presence or absence of SrCad. Three SNP markers tightly linked proximally to SrCad and one SNP that co-segregated with SrCad were completely predictive of the presence or absence of SrCad. These markers also differentiated SrCad from Sr42 and SrTmp which are also located in the same region of chromosome arm 6DS. These markers should be useful in marker-assisted breeding to develop new wheat varieties containing SrCad-based resistance to Ug99 stem rust.
authors.affiliation: National Research Council, 110 Gymnasium Place, Saskatoon, SK, S7N 0W9, Canada.|Agriculture and Agri-Food Canada, Morden Research and Development Centre, 101 Route 100, Morden, MB, R6M 1Y5, Canada.
authors.forename: Mulualem T
authors.initials: MT
authors.lastname: Kassa
authors.affiliation: Agriculture and Agri-Food Canada, Morden Research and Development Centre, 101 Route 100, Morden, MB, R6M 1Y5, Canada.
authors.forename: Frank M
authors.initials: FM
authors.lastname: You
authors.affiliation: Agriculture and Agri-Food Canada, Brandon Research and Development Centre, Brandon, MB, R7A 5Y3, Canada.
authors.forename: Tom G
authors.initials: TG
authors.lastname: Fetch
authors.affiliation: National Research Council, 110 Gymnasium Place, Saskatoon, SK, S7N 0W9, Canada.
authors.forename: Pierre
authors.initials: P
authors.lastname: Fobert
authors.affiliation: National Research Council, 110 Gymnasium Place, Saskatoon, SK, S7N 0W9, Canada.
authors.forename: Andrew
authors.initials: A
authors.lastname: Sharpe
authors.affiliation: Crop Development Centre, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK, S7N 5A8, Canada.
authors.forename: Curtis J
authors.initials: CJ
authors.lastname: Pozniak
authors.affiliation: Agriculture and Agri-Food Canada, Morden Research and Development Centre, 101 Route 100, Morden, MB, R6M 1Y5, Canada.
authors.forename: James G
authors.initials: JG
authors.lastname: Menzies
authors.affiliation: Agriculture and Agri-Food Canada, Morden Research and Development Centre, 101 Route 100, Morden, MB, R6M 1Y5, Canada.
authors.forename: Mark C
authors.initials: MC
authors.lastname: Jordan
authors.affiliation: Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, 960 Carling Ave., Ottawa, ON, K1A 0C6, Canada.
authors.forename: Gavin
authors.initials: G
authors.lastname: Humphreys
authors.affiliation: Department of Plant Sciences, University of California, 276 Hunt Hall and 3111 PES 1 Shields Ave., Davis, CA, 95616, USA.
authors.forename: Tingting
authors.initials: T
authors.lastname: Zhu
authors.affiliation: Department of Plant Sciences, University of California, 276 Hunt Hall and 3111 PES 1 Shields Ave., Davis, CA, 95616, USA.
authors.forename: Ming-Cheng
authors.initials: MC
authors.lastname: Luo
authors.affiliation: Agriculture and Agri-Food Canada, Morden Research and Development Centre, 101 Route 100, Morden, MB, R6M 1Y5, Canada.
authors.forename: Curt A
authors.initials: CA
authors.lastname: McCartney
authors.affiliation: Agriculture and Agri-Food Canada, Morden Research and Development Centre, 101 Route 100, Morden, MB, R6M 1Y5, Canada. colin.hiebert@agr.gc.ca.
authors.forename: Colin W
authors.initials: CW
authors.lastname: Hiebert
mesh_terms: D001487:Basidiomycota; D002874:Chromosome Mapping; D060467:Disease Resistance / Q000235:genetics*; D008040:Genetic Linkage; D005819:Genetic Markers; D060005:Genotyping Techniques; D006239:Haplotypes; D010641:Phenotype; D000069600:Plant Breeding; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D020641:Polymorphism, Single Nucleotide; D014908:Triticum / Q000235:genetics* / Q000382:microbiology
chemical_list: D005819:Genetic Markers