中华芦荟叶的解剖学、组织化学和植物化学研究

用解剖学，组织化学和植物化学方法研究了中华芦荟（Aloe vera L.var.chinensis(Haw.)Berg.)叶的结构，芦荟素的含量及其可能的储藏和合成场所，解剖学研究结果表明，中华芦荟叶的结构由表皮，同化薄壁组织，维管束和储水组织组成，其旱生结构特征比较明显，表皮具厚的角质层，外切向壁次生加厚，气孔下陷，中央储水组织发达，绿色组织没有明显的分化，其中，5个细胞环绕的气孔器和叶基出现的第二轮维管束在芦荟属中首次报道，具有种的特征，中华芦荟叶中所含的蒽醌类次生代谢物主要是芦荟素（barbaloin or aloin)，其含量和叶位及同一叶的不同部位有关，植株上剖嫩叶及每一叶的上部含量高于下部老叶和叶的中部，叶基部含量最低，比较被测的解剖学指标和植物化学分析的结果发现，叶中维管束的密度和芦荟素的含量呈明显的正相关，用5％Pb(CH3COOH)2沉淀处理及5％NaOHR颜色反应检测芦荟素的储藏物合成部位，初步结果表明，位于韧皮部端的数个发达大型薄壁细胞是芦荟素的储藏场所，而绿色组织和维管束鞘是可能的合成场所。

Anatomy, Histochemistry and Phytochemistry of Leaves in Aloe vera var. chinensis

A multidisciplinary approach-anatomy, histochemistry and phytochemistry-was used to investigate the leaf structure, the content and the storage location of barbaloin in the leaves of Aloe vera L. var. chinensis (Haw.) Berg. Xeromorphic characteristics including secondary thickened epidermal cell walls, thicker cuticle, ambiguous differentiation of spongy and palisade tissues in the chlorenchyma, and well_developed aquiferous tissue could be seen in the leaves. Several large parenchymatous cells were observed at the phloem pole of the first ring of vascular bundles. The secondary ring of vascular bundles in the leaf base and the stomata, which are surrounded by five cells, have some classification significance in this species. The density of vascular bundles, the content of barbaloin and the intensity of histochemical reaction differed among leaf numbers L1 (annual leaf), L2 (biennial leaf), L3 (triennial leaf) and L4 (quadrennial leaf), and in different parts of the leaf. These three factors were highest in the youngest leaf, L1, and top parts of all the leaves and lowest in the basal parts and the oldest leaf, L4. The density of vascular bundles had a positive correlation to the content of barbaloin. The histochemical results revealed that the small sheath cells that surrounded the bundles might be the location of barbaloin synthesis and the large parenchymatous cells beneath the sheath might be the storage places of this metabolite.