title: Application of a library of near isogenic lines to understand context dependent expression of QTL for grain yield and adaptive traits in bread wheat.
abstract: Previous quantitative trait loci (QTLs) studies using the Avalon × Cadenza doubled haploid (DH) population identified eleven QTLs determining plant height, heading date and grain yield. The objectives of this study were: (i) to provide insight into the effects of these QTLs using reciprocal multiple near isogenic lines (NILs) with each pair of alleles compared in both parental backgrounds (Avalon or Cadenza), (ii) quantifying epistasis by looking at the background effects and (iii) predict favourable allelic combinations to develop superior genotypes adapted to a target environment.
  
  
  
  To this aim, a library of 553 BC2 NILs and their recurrent parents were tested over two growing seasons (2012/2013 and 2013/2014). The results obtained in the present study validated the plant height, heading date and grain yield QTLs previously identified. Epistatic interactions were detected for the 6B QTL for plant height and heading date, 3A QTL for heading date and grain yield and 2A QTL for grain yield.
  
  
  
  The marker assisted backcrossing strategy used provided an efficient method of resolving QTL for key agronomic traits in wheat as Mendelian factors determining possible epistatic interactions. The study shows that these QTLs are amenable to marker assisted selection, fine mapping, future positional cloning, and physiological trait dissection.
authors.affiliation: Department of Crop Genetics, John Innes Centre, Norwich, NR4 7UH, UK.
authors.forename: Alba
authors.initials: A
authors.lastname: Farré
authors.affiliation: Department of Crop Genetics, John Innes Centre, Norwich, NR4 7UH, UK.
authors.forename: Liz
authors.initials: L
authors.lastname: Sayers
authors.affiliation: Department of Crop Genetics, John Innes Centre, Norwich, NR4 7UH, UK.
authors.forename: Michelle
authors.initials: M
authors.lastname: Leverington-Waite
authors.affiliation: Department of Crop Genetics, John Innes Centre, Norwich, NR4 7UH, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Goram
authors.affiliation: Department of Crop Genetics, John Innes Centre, Norwich, NR4 7UH, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Orford
authors.affiliation: Department of Crop Genetics, John Innes Centre, Norwich, NR4 7UH, UK.
authors.forename: Luzie
authors.initials: L
authors.lastname: Wingen
authors.affiliation: Department of Crop Genetics, John Innes Centre, Norwich, NR4 7UH, UK.
authors.forename: Cathy
authors.initials: C
authors.lastname: Mumford
authors.affiliation: Department of Crop Genetics, John Innes Centre, Norwich, NR4 7UH, UK. Simon.griffiths@jic.ac.uk.
authors.forename: Simon
authors.identifier: 0000-0003-2435-7963
authors.initials: S
authors.lastname: Griffiths
mesh_terms: D032461:Chromosomes, Plant / Q000235:genetics; D006238:Haploidy; D040641:Quantitative Trait Loci / Q000235:genetics*; D014908:Triticum / Q000235:genetics*
keywords: Near isogenic lines; QTL; Wheat; Yield