title: Detection of QTLs for Stagonospora glume blotch resistance in Swiss winter wheat.
abstract: Stagonospora nodorum is the causal agent of the Stagonospora glume blotch disease in hexaploid wheat. The Swiss winter bread wheat cv. 'Arina' has a highly effective, durable and quantitative glume blotch resistance. We studied 240 single seed descent (SSD)-derived lines of an 'Arina x Forno' F(5:7) population to identify and map quantitative trait loci (QTLs) for glume blotch resistance under natural infestation. Using composite interval mapping (CIM) and LOD>4.5, we detected two chromosomal regions on chromosome arms 3BS and 4BL which were specifically associated with glume blotch resistance. These identified QTLs were designated QSng.sfr-3BS and QSng.sfr-4BL, respectively. QSng.sfr-3BS peaked at the locus Xgwm389 in the telomeric region of the short arm of chromosome 3B and explained 31.2% of the observed phenotypic variance for the resistance within the population. The responsible QSng.sfr-3BS allele originated from the resistant parent 'Arina'. The QTL QSng.sfr-4BL (19.1%) mapped to chromosome arm 4BL ('Forno' allele) very close to two known genes, TaMlo and a catalase ( Cat). Both QTL alleles combined could enhance the resistance level by about 50%. Additionally, they showed significant epistatic effects (4.4%). We found PCR-based microsatellite markers closely linked to QSng.sfr-3BS (gwm389) and QSng.sfr-4BL (gwm251) which make marker-assisted selection (MAS) for Stagonospora glume blotch resistance feasible. We also found one resistance QTL, QSng.sfr-5BL, on the long arm of chromosome 5B which overlapped with QTLs for plant height as well as heading time.
authors.affiliation: Institute of Plant Biology, University of Zürich, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Schnurbusch
authors.forename: S
authors.initials: S
authors.lastname: Paillard
authors.forename: D
authors.initials: D
authors.lastname: Fossati
authors.forename: M
authors.initials: M
authors.lastname: Messmer
authors.forename: G
authors.initials: G
authors.lastname: Schachermayr
authors.forename: M
authors.initials: M
authors.lastname: Winzeler
authors.forename: B
authors.initials: B
authors.lastname: Keller
mesh_terms: D000483:Alleles; D002374:Catalase; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics; D005658:Fungi / Q000254:growth & development / Q000472:pathogenicity*; D017343:Genes, Plant / Q000235:genetics; D007113:Immunity, Innate / Q000235:genetics*; D018895:Microsatellite Repeats; D010641:Phenotype; D010935:Plant Diseases / Q000382:microbiology*; D040641:Quantitative Trait Loci; D014908:Triticum / Q000235:genetics* / Q000382:microbiology
chemical_list: D002374:Catalase