title: Genome-wide association mapping for seedling and field resistance to Puccinia striiformis f. sp. tritici in elite durum wheat.
abstract: Genome-wide association analysis in tetraploid wheat revealed novel and diverse loci for seedling and field resistance to stripe rust in elite spring durum wheat accessions from worldwide. Improving resistance to stripe rust, caused by Puccinia striiformis f. sp. tritici, is a major objective for wheat breeding. To identify effective stripe rust resistance loci, a genome-wide association study (GWAS) was conducted using 232 elite durum wheat (Triticum turgidum ssp. durum) lines from worldwide breeding programs. Genotyping with the 90 K iSelect wheat single nucleotide polymorphism (SNP) array resulted in 11,635 markers distributed across the genome. Response to stripe rust infection at the seedling stage revealed resistant and susceptible accessions present in rather balanced frequencies for the six tested races, with a higher frequency of susceptible responses to United States races as compared to Italian races (61.1 vs. 43.1% of susceptible accessions). Resistance at the seedling stage only partially explained adult plant resistance, which was found to be more frequent with 67.7% of accessions resistant across six nurseries in the United States. GWAS identified 82 loci associated with seedling stripe rust resistance, five of which were significant at the false discovery rate adjusted P value <0.1 and 11 loci were detected for the field response at the adult plant stages in at least two environments. Notably, Yrdurum-1BS.1 showed the largest effect for both seedling and field resistance, and is therefore considered as a major locus for resistance in tetraploid wheat. Our GWAS study is the first of its kind for stripe rust resistance in tetraploid wheat and provides an overview of resistance in elite germplasm and reports new loci that can be used in breeding resistant cultivars.
authors.affiliation: Department of Crop and Soil Sciences, Washington State University, Pullman, WA, 99164-6420, USA. weizhen.liu@wsu.edu.
authors.forename: Weizhen
authors.identifier: http://orcid.org/0000-0002-0780-0284
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Agricultural Sciences, University of Bologna, 40127, Bologna, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Maccaferri
authors.affiliation: Department of Crop and Soil Sciences, Washington State University, Pullman, WA, 99164-6420, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Bulli
authors.affiliation: Department of Crop and Soil Sciences, Washington State University, Pullman, WA, 99164-6420, USA.
authors.forename: Sheri
authors.initials: S
authors.lastname: Rynearson
authors.affiliation: Department of Agricultural Sciences, University of Bologna, 40127, Bologna, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Tuberosa
authors.affiliation: Wheat Health, Genetics, and Quality Research Unit, USDA-ARS, Pullman, WA, 99164-6430, USA.|Department of Plant Pathology, Washington State University, Pullman, WA, 99164-6430, USA.
authors.forename: Xianming
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Crop and Soil Sciences, Washington State University, Pullman, WA, 99164-6420, USA. m.pumphrey@wsu.edu.
authors.forename: Michael
authors.initials: M
authors.lastname: Pumphrey
mesh_terms: D001487:Basidiomycota; D001499:Bayes Theorem; D002874:Chromosome Mapping; D016000:Cluster Analysis; D018744:DNA, Plant / Q000235:genetics; D060467:Disease Resistance / Q000235:genetics*; D056726:Genetic Association Studies; D005819:Genetic Markers; D005838:Genotype; D015810:Linkage Disequilibrium; D010641:Phenotype; D000069600:Plant Breeding; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D036226:Seedlings / Q000235:genetics / Q000382:microbiology; D057891:Tetraploidy; D014908:Triticum / Q000235:genetics* / Q000382:microbiology
chemical_list: D018744:DNA, Plant; D005819:Genetic Markers