Fig. 5

PtFT2 expression affects short-day induced growth cessation and bud set in P. tremula. a Bud set phenotype under 19-h day-length conditions. Two southern clones (marked with a red box, SwAsp 018, Ronneby, latitude 56.2 °N; SwAsp 023, Vårgårda, latitudes 58 °N) and two northern clones (marked with a blue box, SwAsp 100, Umeå, latitude 63.9 °N; SwAsp 112, Luleå, latitudes 65.7 °N) were chosen to be analyzed. Trees were grown under 23-h day length for one month and then shifted to 19-h day length. Photos were taken one month after the shift to 19-h day length. b Dynamic expression analysis of PtFT2 in two southern clones (red, SwAsp018 and SwAsp023) and two northern clones (blue, SwAsp100 and SwAsp112) from the greenhouse experiment. The genotypes of these trees at the most strongly associated PtFT2 SNP are SwAsp018: T/T, SwAsp023: T/T, SwAsp100: not available and SwAsp 112: G/G. Samples for RT-PCR were taken two weeks after the trees were shifted to 19-h day length. Error bars, ±standard deviation. ZT zeitgeber time. c Dynamic expression analysis of PtFT2 in two southern clones (red, SwAsp005 and SwAsp023) and two northern clones (blue, SwAsp100 and SwAsp116) from common garden experiment. The genotypes of these trees at the most strongly associated PtFT2 SNP are SwAsp005: T/T, SwAsp023: T/T, SwAsp100: not available and SwAsp 112: G/G. Samples were collected in the Sävar common garden in early July 2014