Fig. 6

Statistical significance and direction of relationships between estimated relative abundances of sequence reads and PCR cycle number (Additional file 18: Figure S9) in dataset 3. The dots represent p values from linear regression models, with green and red representing positive and negative relationships, respectively. The species are ordered according to the GC content on the sequenced fragment (vertical lines). The dotted blue lines signifies the significance threshold of p = 0.05 (left axis), while the dotted black line represents the mean GC percentage (right axis)