title: Genetic control of protein content and sedimentation volume in European winter wheat cultivars.
abstract: Breeding of bread wheat in the last decades has maintained a high baking quality despite the intensive selection for grain yield. The quality trait sedimentation volume but not protein content is mainly controlled by the Glu - A1, Glu - B1, Glu - D1, Gli - B1 , and Pinb - D1 loci which are differentially used in varieties from different European origins. Protein content and sedimentation volume are two important quality traits in wheat breeding. In this study, we used a panel of 407 European winter wheat cultivars to dissect the genetic architecture of both traits and to assess the potential of genomics-assisted breeding. All lines were phenotyped in multi-location field trials, genotyped by a genotyping-by-sequencing approach, and assessed for the alleles at the Glu-A1, Glu-B1, Glu-D1, Gli-B1, and Pinb-D1 candidate loci. Our analyses revealed no effect of the candidate loci on protein content, but a strong effect on sedimentation volume, with Glu-B1 and Gli-B1 explaining 24.6 and 19.5 % of the genotypic variance, respectively. The genome-wide scan identified three quantitative trait loci (QTL) for protein content which jointly explained only 18.5 % of the genotypic variance. In contrast, four QTL were detected for sedimentation volume most likely identifying the Glu-B1 and Gli-B1 candidate loci and explaining approximately 60 % of the genotypic variance. We observed differences for both traits between countries of origin of the cultivars, accompanied by corresponding geographic differences in QTL allele frequencies. Furthermore, a genome-wide prediction approach resulted in a higher predictive ability for both traits as compared to marker-assisted selection based on the identified QTL. Taken together, our results illustrate a different genetic architecture of the two quality traits and show the potential of their genomics-assisted improvement.
authors.affiliation: State Plant Breeding Institute, University of Hohenheim, 70593, Stuttgart, Germany. tobias.wuerschum@uni-hohenheim.de.
authors.forename: Tobias
authors.initials: T
authors.lastname: Würschum
authors.affiliation: State Plant Breeding Institute, University of Hohenheim, 70593, Stuttgart, Germany.
authors.forename: Willmar L
authors.initials: WL
authors.lastname: Leiser
authors.affiliation: Syngenta Seeds, 39387, Hadmersleben, Germany.
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Kazman
authors.affiliation: State Plant Breeding Institute, University of Hohenheim, 70593, Stuttgart, Germany.
authors.forename: C Friedrich H
authors.initials: CF
authors.lastname: Longin
mesh_terms: D002874:Chromosome Mapping; D002523:Edible Grain / Q000235:genetics*; D005787:Gene Frequency; D005838:Genotype; D005903:Gliadin / Q000235:genetics; D005983:Glutens / Q000235:genetics*; D010641:Phenotype; D000069600:Plant Breeding; D040641:Quantitative Trait Loci; D014908:Triticum / Q000235:genetics*
chemical_list: D005983:Glutens; D005903:Gliadin