title: Impact of transgene genome location on gene migration from herbicide-resistant wheat (Triticum aestivum L.) to jointed goatgrass (Aegilops cylindrica Host).
abstract: BACKGROUND
  Wheat (Triticum aestivum) (ABD) and jointed goatgrass (Aegilops cylindrica) (CD) can cross and produce hybrids that can backcross to either parent. Such backcrosses can result in progeny with chromosomes and/or chromosome segments retained from wheat. Thus, a herbicide resistance gene could migrate from wheat to jointed goatgrass. In theory, the risk of gene migration from herbicide-resistant wheat to jointed goatgrass is more likely if the gene is located on the D genome and less likely if the gene is located on the A or B genome of wheat.
  
  
  RESULTS
  BC1populations (jointed goatgrass as a recurrent parent) were analyzed for chromosome numbers and transgene transmission rates under sprayed and non-sprayed conditions. Transgene retention in the non-sprayed BC1generation for the A, B and D genomes was 84, 60 and 64% respectively. In the sprayed populations, the retention was 81, 59 and 74% respectively.
  
  
  CONCLUSIONS
  The gene transmission rates were higher than the expected 50% or less under sprayed and non-sprayed conditions, possibly owing to meiotic chromosome restitution and/or chromosome non-disjunction. Such high transmission rates in the BC1generation negates the benefits of gene placement for reducing the potential of gene migration from wheat to jointed goatgrass. © 2016 Society of Chemical Industry.
authors.affiliation: Department of Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID, USA.
authors.forename: Maqsood
authors.initials: M
authors.lastname: Rehman
authors.affiliation: Department of Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID, USA.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Hansen
authors.affiliation: Department of Crop and Soil Science, Oregon State University, Corvallis, OR, USA.
authors.forename: Carol A
authors.initials: CA
authors.lastname: Mallory-Smith
authors.affiliation: Department of Crop and Soil Science, Oregon State University, Corvallis, OR, USA.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Zemetra
mesh_terms: D032461:Chromosomes, Plant / Q000235:genetics; D017343:Genes, Plant / Q000235:genetics*; D053209:Herbicide Resistance / Q000235:genetics*; D006824:Hybridization, Genetic; D006109:Poaceae / Q000235:genetics*; D019076:Transgenes / Q000235:genetics*; D014908:Triticum / Q000235:genetics* / Q000502:physiology*
keywords: gene flow; glyphosate resistance; jointed goatgrass; wheat