Abstract: The size, form and connection mode of vessel displayed an important role in water transportation and stress support of the plant. Based on resin casting method, the three-dimensional structure characteristics of the vessels of four plant species, i.e. Populus tomentosa Carr, Salix matsudana, Ulmus pumila L. and Wisteria sinensis were comparatively studied. The relationship between the vessel structure characteristics and water transportation was analyzed. The vessel wall structure was printed in molded surface, which can be examined with SEM. The results showed that: the structure characteristics of the vessel element of P.tomentosa Carr are similar to those of S.matsudana. However, they are significant different from U.pumila L. and W.sinensis, and more primitive than U.pumila L. and W.sinensis. The vessel elements of P.tomentosa Carr and S.matsudana are long, and the pits are less, which is beneficial to water transport. The vessel elements of U.pumila L. and W.sinensis are relatively wide and straight of the end wall, which are helpful for water transport. There is spiral thickening for U.pumila L. and W.sinensis, which increase the mechanical strength of vessel and decrease the risk of cavitations, consequently improve the efficiency of water transport.

Key words: resin casting method, scanning electron microscope(SEM), vessel element, water transportation, vessel structure