Abstract:

The occurrence and morphology of tyloses and gums in vessels of 102 Chinese hardwood were investigated using SEM. Tyloses were present in 49 species and gums in 12 species. Morphological types of tyloses are: foamed, ladder-, collasped-shaped, globular. Morphological types of gums are: vessels occlusied, thin layer, small droplet. The mean values of length and width pit aperture of vessel to parenchyma pit were greater than 3 and 2μm, respectively, in species having tyloses and were less than these values in species having gums. The obeservation of ultrathin section of Robinia pseudoacacia wood by TEM showed: the tyloses walls has a compound middle lamella and primary walls with simple pits. There are more tyloses and gums in vessele of pith of 3 species. The content of tyloses and gums decreased in vessels of each growth ring from pith to bark.

Key words: Tyloses, Gums, Vessels, Pit aperture of vessel to parenchyma pit, Hardwood