title: Reduced Height (Rht) Alleles Affect Wheat Grain Quality.
abstract: The effects of dwarfing alleles (reduced height, Rht) in near isogenic lines on wheat grain quality are characterised in field experiments and related to effects on crop height, grain yield and GA-sensitivity. Alleles included those that conferred GA-insensitivity (Rht-B1b, Rht-B1c, Rht-D1b, Rht-D1c) as well as those that retained GA-sensitivity (rht(tall), Rht8, Rht8 + Ppd-D1a, Rht12). Full characterisation was facilitated by including factors with which the effects of Rht alleles are known to interact for grain yield (i.e. system, [conventional or organic]; tillage intensity [plough-based, minimum or zero]; nitrogen fertilizer level [0-450 kg N/ha]; and genetic backgrounds varying in height [cvs Maris Huntsman, Maris Widgeon, and Mercia]. Allele effects on mean grain weight and grain specific weight were positively associated with final crop height: dwarfing reduced these quality criteria irrespective of crop management or GA-sensitivity. In all but two experiments the effects of dwarfing alleles on grain nitrogen and sulphur concentrations were closely and negatively related to effects on grain yield, e.g. a quadratic relationship between grain yield and crop height manipulated by the GA-insensitive alleles was mirrored by quadratic relationships for nitrogen and sulphur concentrations: the highest yields and most dilute concentrations occurred around 80cm. In one of the two exceptional experiments the GA-insensitive Rht-B1b and Rht-B1c significantly (P<0.05) reduced grain nitrogen concentration in the absence of an effect on yield, and in the remaining experiment the GA-sensitive Rht8 significantly reduced both grain yield and grain nitrogen concentration simultaneously. When Rht alleles diluted grain nitrogen concentration, N:S ratios and SDS-sedimentation volumes were often improved. Hagberg falling number (HFN) was negatively related to crop height but benefits from dwarfing were only seen for GA-insensitive alleles. For HFN, therefore, there was the strongest evidence for a direct pleiotropic effect of GA-insensitivity, rather than an effect consequential to yield and/or height.
authors.affiliation: School of Agriculture, Policy and Development, University of Reading, Reading, Berkshire, United Kingdom.
authors.forename: Richard
authors.initials: R
authors.lastname: Casebow
authors.affiliation: School of Agriculture, Policy and Development, University of Reading, Reading, Berkshire, United Kingdom.
authors.forename: Caroline
authors.initials: C
authors.lastname: Hadley
authors.affiliation: School of Agriculture, Policy and Development, University of Reading, Reading, Berkshire, United Kingdom.
authors.forename: Rajneet
authors.initials: R
authors.lastname: Uppal
authors.affiliation: School of Agriculture, Policy and Development, University of Reading, Reading, Berkshire, United Kingdom.
authors.forename: Molla
authors.initials: M
authors.lastname: Addisu
authors.affiliation: Department of Environmental Agronomy and Crop Sciences, University of Padova, Legnaro, Padova, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Loddo
authors.affiliation: John Innes Centre, Norwich, Norfolk, United Kingdom.
authors.forename: Ania
authors.initials: A
authors.lastname: Kowalski
authors.affiliation: John Innes Centre, Norwich, Norfolk, United Kingdom.
authors.forename: Simon
authors.initials: S
authors.lastname: Griffiths
authors.affiliation: Institute of Biological, Environmental and Rural Sciences, University of Aberystwyth, Aberystwyth, Ceredigion, United Kingdom.
authors.forename: Mike
authors.initials: M
authors.lastname: Gooding
mesh_terms: D000483:Alleles; D002523:Edible Grain / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000592:standards; D005308:Fertilizers; D017343:Genes, Plant; D010937:Plant Growth Regulators / Q000494:pharmacology; D014908:Triticum / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development
chemical_list: D005308:Fertilizers; D010937:Plant Growth Regulators