Adaptation of tree growth to elevated CO2: quantitative trait loci for biomass in Populus


Author for correspondence: Gail Taylor Tel: +44 (0)23 80592335 Fax: +44 (0)23 80594459 Email:


  • • Information on the genetic variation of plant response to elevated CO2 (e[CO2]) is needed to understand plant adaptation and to pinpoint likely evolutionary response to future high atmospheric CO2 concentrations.
  • • Here, quantitative trait loci (QTL) for above- and below-ground tree growth were determined in a pedigree – an F2 hybrid of poplar (Populus trichocarpa and Populus deltoides), following season-long exposure to either current day ambient CO2 (a[CO2]) or e[CO2] at 600 µl l−1, and genotype by environment interactions investigated.
  • • In the F2 generation, both above- and below-ground growth showed a significant increase in e[CO2]. Three areas of the genome on linkage groups I, IX and XII were identified as important in determining above-ground growth response to e[CO2], while an additional three areas of the genome on linkage groups IV, XVI and XIX appeared important in determining root growth response to e[CO2].
  • • These results quantify and identify genetic variation in response to e[CO2] and provide an insight into genomic response to the changing environment.