Figure 1.

Interspecific comparison of hybridization intensities in secondary xylem.A-F: Pair-wise comparison of white spruce and six other species based on the number of shared positive probes indicated in the plots. The squared correlation coefficients (r²) are as follows 0.86 (A), 0.85 (B), 0.89 (C), 0.29 (D), 0.22 (E) and 0.27 (F). G: Analysis of signal intensity variation between species; the fold change (FC) was determined from the average normalized signal intensities (log2 scale). An FC of 1 or −1 represents a two-fold signal increase or decrease, respectively. For phelloderm results, see Additional file 4: Figure S3.