Fig. 2

QTL anchored to the genome of Populus trichocarpa (V3 assembly, Kelleher et al., 2007). a: linkage groups I, II, VI, b: linkage groups XII, XIII, XVII. The actual map has a high marker density (average marker spacing: 5 markers per 4 cM). For illustration purposes, for each linkage group an evenly spaced selection of scaffolds is shown (1 marker per 20 cM). The yellow regions on LGs represent LOD score maxima across years and environments. QTL for bark texture (BT), diameter (D), and bark thickness (BTh) are shown in red, green, and blue for Oregon and in pink, light green, and turquois for West Virginia and named according to Additional file 4: Table S2. LOD score maxima, genome-wide intervals (solid bars) and chromosome-wide intervals are shown for QTL that were identified in different years and environments (see Additional file 4: Table S2). The outer lines of bars are CW thresholds and middle lines are QTL LOD maxima. The exact map and physical locations of QTL are shown in Additional file 4: Table S2. Scaffold intervals are represented in Mb. Black vertical lines represent the physical location of LBD genes in the P. trichocarpa genome, orthologues are notes by a, b or c