title: Mutations in wheat exhibiting growth-stage-specific resistance to biotrophic fungal pathogens.
abstract: Two mutants were isolated in wheat that showed enhanced resistance towards Puccinia striiformis f. sp. tritici, the fungal causal agent of yellow rust. The altered phenotype of I3-48 is due to a minimum of two mutation events, each showing a partial, additive effect, with one mutation segregating with a deletion on the long arm of chromosome 4D. In the case of I3-54, the enhanced resistance is due to a single, dominant mutation. In both mutants, the expression of the enhanced resistance is growth-stage specific. With I3-54, the full resistance phenotype is apparent from the third seedling leaf onwards, while with I3-48, a full resistance phenotype is only seen on the tenth and subsequent leaves. In addition to the enhanced resistance towards yellow rust, I3-48 also shows enhanced resistance towards brown rust, and I3-54 shows enhanced resistance to powdery mildew.
authors.affiliation: Department of Disease and Stress Biology, John Innes Centre, Colney Lane, Norwich Research Park, Norwich, NR4 7UH, UK.
authors.forename: Phil H
authors.initials: PH
authors.lastname: Smith
authors.forename: John A
authors.initials: JA
authors.lastname: Howie
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Worland
authors.forename: Rebecca
authors.initials: R
authors.lastname: Stratford
authors.forename: Lesley A
authors.initials: LA
authors.lastname: Boyd
mesh_terms: D001487:Basidiomycota / Q000472:pathogenicity*; D002874:Chromosome Mapping; D004198:Disease Susceptibility; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D009154:Mutation; D010641:Phenotype; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D018515:Plant Leaves / Q000382:microbiology; D011123:Polyploidy; D014908:Triticum / Q000235:genetics* / Q000382:microbiology*