A novel method for the easy and detailed visualization of water pathways (i.e., xylem vessels) involving girdling after staining is proposed. This technique was applied to intact seedlings as well as seedlings whose vessels were intentionally damaged to evaluate the effectiveness of the procedure.
The applicability of the technique to grafted fruit-vegetable seedlings was tested using tomato seedlings (Lycopersicon esculentum Mill. ‘Momotaro’). The vessels were stained with congo red via the roots prior to girdling. This technique is unique in that it allows the visualization of the vessel network by a simple procedure as well as the continuous and unambiguous observation of the vertical and horizontal networks of vessels. Using the technique, we can observe a complex network of vessels, including vessel branching and vessel regeneration after damage.