摘要
利用光镜和扫描电镜对伯乐树（Ｂｒｅｔｓｃｈｎｅｉｄｅｒａ ｓｉｎｅｎｓｉｓＨｅｍ ｓｌ．）茎次生木质部的结构进行了研究。其主要特征为：（１）散孔材，有较明显的生长轮；（２）导管分子多为单穿孔板，少数为梯形复穿孔板，具螺纹加厚；（３）管胞、纤维－管胞和韧型木纤维同时存在，后两者有的具分隔；（４）木薄壁组织以轮界分布为主；（５）木射线多为大型异形射线，属异形ＩＩＢ型；（６）缺乏侵填体、树脂道及分泌细胞。对伯乐树科（Ｂｒｅｔｓｃｈｎｅｉｄｅｒａｃｅａｅ）的系统位置作了探讨。
The anatomical structure of the wood of Bretschneidera sinensis Hemsl. was studied with both light and scanning electron microscopy. The main characters of the secondary xylem are as follows: (1) The wood is diffuse porous with distinct growth ring. (2) Most vessel elements possess simple perforation plates, only a few are with scalariform perforation plates; but both of them have spiral thickenings on their secondary walls. (3) Tracheids, fiber tracheids and libriform fibers all exist and the libriform fibers may or may not have septa. (4) Wood parenchyma is mainly of terminal distribution type. (5) Wood ray is heterogenous belonging to the Krib′s heterogenous IIB type. (6) Tylosis, resin canal and secretory cell are absent. Based on the present study and other data derived from external morphology, bark anatomy, chromosome study, palynology and embryogenetic study, the systematic position of Bretschneidera sinensis was analysed and discussed. The authors agree that the genus should be elevated to the level of a monotypic family——Bretschneideraceae, belonging to the order of Sapindales; also it is closely related to other primitive families of the same order such as Staphyleaceae, Sabiaceae and Connaraceae.
基金
国家自然科学基金
关键词
伯乐树
次生木质部
系统位置
结构
Bretschneidera sinensis
Secondary xylem
Systematic position
