地黄叶和茎的解剖学及组织化学研究

Anatomy and Histochemistry of the Leaf of Rehmannia glutinosa Libosch.ex Fisch(Scrophulariaceae)

采用解剖学和组织化学方法对地黄叶和茎的显微结构以及梓醇、多糖的分布进行观察研究,以明确梓醇和多糖在地黄叶和茎中的分布特征。结果显示:(1)地黄叶的上、下表皮均分布有腺毛和非腺毛,腺毛都属于头状腺毛,包括长柄和短柄的头状腺毛,两类腺毛的分泌物化学成分主要是黄酮和多糖;叶的上、下表皮上都分布有无规则型气孔,下表皮的气孔密度比上表皮的大,但气孔指数相差不大;栅栏组织由2～3层薄壁细胞构成,排列紧密,海绵组织薄壁细胞形状无规则,细胞间隙大。(2)组织化学研究表明,海绵组织中黄斑样的薄壁细胞是梓醇和多糖的贮存场所,这类薄壁细胞在叶片边缘的齿末端处最为集中,茎的皮层、韧皮部和木质部的薄壁细胞也都是梓醇和多糖的贮存场所。

Anatomical and histochemical methods were used to investigate micromorphological characters and locality of catalpol and polysaccharide in Rehrnannia glutinosa leaves. （1）Both adaxial and abaxial leaf surface of R. glutinosa possess glandular and non-glandular trichomes. Glandular trichomes can be classi- fied into short-stalked and long-stalked. The secretion of these glandular trichomes is mainly compounds of {lavnoids and polysaccharide. Anomocytic stomata are distributed on both leaf surfaces. Although stomatal density of abaxial surface is well above than that of adaxial surface, but stomatal index difference is mod- est. Palisade parenchyma cells are arranged densely in two to three layers. Irregular spongy parenchyma ceils have irregular-shaped cells with large intercellular spaces. （B）Histochemical tests indicated that yellow-speckled spongy parenchyma cells which concentrate at the end of the teeth near the leaf margin contain a combination of catalpol and polysaccharide. Parenchyma cells in cortex,phloem and xylem are lo- cality of catalpol and polvsaccharide.