title: Genetic Basis for Variation in Wheat Grain Yield in Response to Varying Nitrogen Application.
abstract: Nitrogen (N) is a major nutrient needed to attain optimal grain yield (GY) in all environments. Nitrogen fertilisers represent a significant production cost, in both monetary and environmental terms. Developing genotypes capable of taking up N early during development while limiting biomass production after establishment and showing high N-use efficiency (NUE) would be economically beneficial. Genetic variation in NUE has been shown previously. Here we describe the genetic characterisation of NUE and identify genetic loci underlying N response under different N fertiliser regimes in a bread wheat population of doubled-haploid lines derived from a cross between two Australian genotypes (RAC875 × Kukri) bred for a similar production environment. NUE field trials were carried out at four sites in South Australia and two in Western Australia across three seasons. There was genotype-by-environment-by-treatment interaction across the sites and also good transgressive segregation for yield under different N supply in the population. We detected some significant Quantitative Trait Loci (QTL) associated with NUE and N response at different rates of N application across the sites and years. It was also possible to identify lines showing positive N response based on the rankings of their Best Linear Unbiased Predictions (BLUPs) within a trial. Dissecting the complexity of the N effect on yield through QTL analysis is a key step towards elucidating the molecular and physiological basis of NUE in wheat.
authors.affiliation: Australian Centre for Plant Functional Genomics (ACPFG), The University of Adelaide, PMB1, Glen Osmond, SA, 5064, Australia.
authors.forename: Saba
authors.initials: S
authors.lastname: Mahjourimajd
authors.affiliation: School of Agriculture, Food and Wine, Waite Research Institute, The University of Adelaide, PMB 1, Glen Osmond, SA, 5064, Australia.
authors.forename: Julian
authors.initials: J
authors.lastname: Taylor
authors.affiliation: Australian Centre for Plant Functional Genomics (ACPFG), The University of Adelaide, PMB1, Glen Osmond, SA, 5064, Australia.
authors.forename: Beata
authors.initials: B
authors.lastname: Sznajder
authors.affiliation: Australian Centre for Plant Functional Genomics (ACPFG), The University of Adelaide, PMB1, Glen Osmond, SA, 5064, Australia.
authors.forename: Andy
authors.initials: A
authors.lastname: Timmins
authors.affiliation: Australian Centre for Plant Functional Genomics (ACPFG), The University of Adelaide, PMB1, Glen Osmond, SA, 5064, Australia.
authors.forename: Fahimeh
authors.initials: F
authors.lastname: Shahinnia
authors.affiliation: Soil Science and Plant Nutrition M087, School of Earth and Environment, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.
authors.forename: Zed
authors.initials: Z
authors.lastname: Rengel
authors.affiliation: Soil Science and Plant Nutrition M087, School of Earth and Environment, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.
authors.forename: Hossein
authors.initials: H
authors.lastname: Khabaz-Saberi
authors.affiliation: Australian Grain Technologies, PMB1, Glen Osmond, SA, 5064, Australia.|School of Agriculture, Food and Wine, Waite Research Institute, The University of Adelaide, PMB 1, Glen Osmond, SA, 5064, Australia.
authors.forename: Haydn
authors.initials: H
authors.lastname: Kuchel
authors.affiliation: Australian Centre for Plant Functional Genomics (ACPFG), The University of Adelaide, PMB1, Glen Osmond, SA, 5064, Australia.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Okamoto
authors.affiliation: School of Agriculture, Food and Wine, Waite Research Institute, The University of Adelaide, PMB 1, Glen Osmond, SA, 5064, Australia.
authors.forename: Peter
authors.identifier: http://orcid.org/0000-0001-9494-400X
authors.initials: P
authors.lastname: Langridge
mesh_terms: D018533:Biomass; D001947:Breeding; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D002523:Edible Grain; D004777:Environment; D005308:Fertilizers; D056726:Genetic Association Studies; D008040:Genetic Linkage; D005838:Genotype; D009584:Nitrogen / Q000378:metabolism*; D040641:Quantitative Trait Loci; D019655:Quantitative Trait, Heritable; D014908:Triticum / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*
chemical_list: D005308:Fertilizers; D009584:Nitrogen