偏光顕微鏡法による広葉樹材道管二次壁の層構成

Abstract

日本産広葉樹材33種, 南洋材9種について, 道管二次壁の層構成を2 - 3μm厚の木口切片と傾斜切片を用いて偏光顕微鏡十字ニコル間で観察した。その結果, 認められた層構成は (1) 典型的な3層を示すもの (Fig. 2), (2) 均一な複屈折を示し3層の区別が明確でないもの (Fig. 3), (3) 多層を示すもの (Fig. 4, 5) である。樹種別の層構成をTable1, 2に示したが, 日本産広葉樹材において, 散孔材で (1) と (2), 環孔材で (1), (2) および (3), 放射孔材では (3) の層構成をもっていることがわかる。また, 南洋材では散孔材のみであるが, (1) と (3) の層構成をもっている。

In 33 species of Japanese hardwoods and 9 species of tropical hardwoods, the layered structure in the secondary wall of vessels was observed using thin transverse and oblique sections between crossed nicols. As a result of examinations the layered structure was classified into the three types; (1) the typical three-layered structure (Fig. 2), (2) the structure showing the uniform birefrigence, so that the layered structure is not detected (Fig. 3), (3) the multi-layered structure (Figs. 4 and 5) The layered structure for each species is shown in Table 1 and 2. It is shown that in Japanese hardwoods, the diffuse-porous woods have the types of (1) and (2), ring-porous woods have the types of (1), (2) and (3), and radial-porous woods have the type of (3), and that tropical hardwoods all of which belong to diffuse-porous wood, have the types of (1) and (3).