Figure 1

Cq distributions for each candidate reference gene. Expression data for reference genes where each graphed point represents the mean of the technical replicates. Each graph shows the quantification cycle (Cq) distribution for candidate reference genes in shoot tips/buds, young leaves, mature leaves and bark of both genotypes (P. trichocarpa and P. tremula x P. alba). LD, long day photoperiod; SD, short day photoperiod.