Figure 1.

Illustration of some characters that can be measured on a transverse section of Prunus domestica. (A) The original image, (B) the same image modified for image-analysis. Diameter (D) and perimeter (P) are easily measured on transverse sections. For calculating the vessel grouping index (V_G), the number of vessel groups and the total number of vessels has to be determined. Light blue, solitary vessels (one vessel per group); dark blue, vessel multiples (two or more vessels per group). Pink lines, (inter) vessel contact length (L_VW). Green polygon, AOI (area of interest), covering earlywood and latewood. All vessels outside the AOI were excluded. Scale bar = 100 μm.