title: Discovery and characterization of two new stem rust resistance genes in Aegilops sharonensis.
abstract: We identified two novel wheat stem rust resistance genes, Sr-1644-1Sh and Sr-1644-5Sh in Aegilops sharonensis that are effective against widely virulent African races of the wheat stem rust pathogen. Stem rust is one of the most important diseases of wheat in the world. When single stem rust resistance (Sr) genes are deployed in wheat, they are often rapidly overcome by the pathogen. To this end, we initiated a search for novel sources of resistance in diverse wheat relatives and identified the wild goatgrass species Aegilops sharonesis (Sharon goatgrass) as a rich reservoir of resistance to wheat stem rust. The objectives of this study were to discover and map novel Sr genes in Ae. sharonensis and to explore the possibility of identifying new Sr genes by genome-wide association study (GWAS). We developed two biparental populations between resistant and susceptible accessions of Ae. sharonensis and performed QTL and linkage analysis. In an F6recombinant inbred line and an F2population, two genes were identified that mapped to the short arm of chromosome 1Ssh, designated as Sr-1644-1Sh, and the long arm of chromosome 5Ssh, designated as Sr-1644-5Sh. The gene Sr-1644-1Sh confers a high level of resistance to race TTKSK (a member of the Ug99 race group), while the gene Sr-1644-5Sh conditions strong resistance to TRTTF, another widely virulent race found in Yemen. Additionally, GWAS was conducted on 125 diverse Ae. sharonensis accessions for stem rust resistance. The gene Sr-1644-1Sh was detected by GWAS, while Sr-1644-5Sh was not detected, indicating that the effectiveness of GWAS might be affected by marker density, population structure, low allele frequency and other factors.
authors.affiliation: John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.|2Blades Foundation, 1630 Chicago Avenue, Suite 1901, Evanston, IL, 60201, USA.
authors.forename: Guotai
authors.initials: G
authors.lastname: Yu
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK.|J.R. Simplot Company, 5369 West Irving Street, Boise, ID, 83706, USA.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Champouret
authors.affiliation: John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
authors.forename: Burkhard
authors.initials: B
authors.lastname: Steuernagel
authors.affiliation: Department of Plant Pathology, University of Minnesota, Saint Paul, MN, 55108, USA.
authors.forename: Pablo D
authors.initials: PD
authors.lastname: Olivera
authors.affiliation: Department of Plant Pathology, University of Minnesota, Saint Paul, MN, 55108, USA.
authors.forename: Jamie
authors.initials: J
authors.lastname: Simmons
authors.affiliation: Department of Plant Pathology, University of Minnesota, Saint Paul, MN, 55108, USA.
authors.forename: Cole
authors.initials: C
authors.lastname: Williams
authors.affiliation: Department of Plant Pathology, University of Minnesota, Saint Paul, MN, 55108, USA.
authors.forename: Ryan
authors.initials: R
authors.lastname: Johnson
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Moscou
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Hernández-Pinzón
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK.
authors.forename: Phon
authors.initials: P
authors.lastname: Green
authors.affiliation: Institute for Cereal Crops Improvement, Tel Aviv University, Tel Aviv, 69978, Israel.
authors.forename: Hanan
authors.initials: H
authors.lastname: Sela
authors.affiliation: Institute for Cereal Crops Improvement, Tel Aviv University, Tel Aviv, 69978, Israel.
authors.forename: Eitan
authors.initials: E
authors.lastname: Millet
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK.
authors.forename: Jonathan D G
authors.initials: JDG
authors.lastname: Jones
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK.|2Blades Foundation, 1630 Chicago Avenue, Suite 1901, Evanston, IL, 60201, USA.|AgBiome Inc, 104 T. W. Alexander Drive, Building 1, Research Triangle Park, NC, 27709, USA.
authors.forename: Eric R
authors.initials: ER
authors.lastname: Ward
authors.affiliation: Department of Plant Pathology, University of Minnesota, Saint Paul, MN, 55108, USA.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Steffenson
authors.affiliation: John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK. Brande.wulff@jic.ac.uk.|The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK. Brande.wulff@jic.ac.uk.
authors.forename: Brande B H
authors.initials: BBH
authors.lastname: Wulff
mesh_terms: D001487:Basidiomycota; D002874:Chromosome Mapping; D060467:Disease Resistance / Q000235:genetics*; D017343:Genes, Plant; D056726:Genetic Association Studies; D008040:Genetic Linkage; D016014:Linear Models; D015810:Linkage Disequilibrium; D008957:Models, Genetic; D010641:Phenotype; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D006109:Poaceae / Q000235:genetics* / Q000382:microbiology; D040641:Quantitative Trait Loci