摘要
本文对生长在我国西北沙漠地区的6种锦鸡儿属(Caragana Fabr.)植物的次生木质部结构进行了比较观察。它们的主要共同点是:导管分布频率和复孔率高,导管的平均直径小,细胞壁较厚,具两种直径的导管;导管分子很短,具单穿孔;管间纹孔为互列的具缘纹孔,并有附物纹孔;导管次生壁上常见螺纹加厚韧型纤维很短,具数目较少的单纹孔,壁较厚。射线的平均高度很低,单列、多列射线都存在,均为异型射线。此外,它们之间在横切面上导管的分布形式、轴向薄壁细胞的分布及数量、射线分布频率、晶体的存在及分布等特征上均有差异,根据这些差异本文提出了对6种沙生锦鸡儿次生木质部结构鉴定的检索表。
The structures of secondary xylem of 6 species of Caragana,which grow in desert re- gions of Northwest of China,are described in details.The main quantitative characters are compared with species.And a key to the identification of wood structures of 6 species is given.The main similarities of secondary xylem of these 6 species are as follows:vessels per mm^2 very numerous,percentage of multiple vessels high;vessel elements very short,perfora- tions simple and in almost horizontal end walls;intervessel bordered pits alternate and vestur- ed,and vessels with spiral thickenings.Libriform fibres are very short,and usually with thick end walls,and with simple pits.Rays are heigh to very low,and with multiseriate and uniseriate,and with heterogeneous type Ⅰ and Ⅱ.In addition,there are differences in other characters,e.g.vessel distribution,amount of axial parenchyma and distribution,ray frequency, crystals present or absent,and crystal distribution,if present.These differences can be used as the anatomical characters to identify the wood structures of the 6 species.In this article we also discuss the relation between the structure of xylem elements and the environmental in- fluences.
基金
国家自然科学基金
关键词
锦鸡儿属
沙生植物
次生木质部
Caragana
Desert plant
Secondary xylem anatomy
Xerophyte
