Abstract:

In the paper the results of wood tissue microt-dissection of four Casuarina strains are reported, the physical ciharacteristics of wood vessels, lignified cells between vessels and rays are reported, and the mechanism of insect resistance is carified. The wood vessel number of the high-resistant strain C₄₄ is few and the unit area (1mm²) contains only 20.25 vessels which account for merely 9.72% of the wood area; the lignified cells between vessles are relatively evident and the ratio of wall thickness to lumen diameter is maximal (56.59%); the indexs of the beam number, length and width of rays within the unit area and the area proportion are minimal. The above-mentioned show that the xylem water content of the strain is low, its wood is hard and compact and the nutrients provided by the xylem are few, which are unfavourable to the survival and development of the larvae of Anoplophora chinensis (a stem-boring pest).

Key words: Casuarina, Cell Structure, Vessel, Lignified Cell, Ray, Resistance