白芷叶中分泌道显微和超微结构的研究

本文对白芷叶中分泌道的显微和超微结构进行了研究。白芷叶中分泌道是由一层上皮细胞围绕一圆形腔道而成,分布于叶片、叶鞘和叶柄的薄壁组织及较大叶脉或维管组织的次生韧皮部中,分泌道的发生方式为裂生型,其腔隙的扩大主要依靠上皮细胞本身的分裂生长以及周围细胞插入到上皮细胞之间。电镜观察结果表明分泌道原始细胞之间裂开形成腔隙可能与高尔基体分泌果胶酶进入到相邻细胞壁间而导致中层溶解有关,成熟分泌道上皮细胞中含有丰富的质体和内质网,其中大多数质体被内质网鞘所围绕,分泌道发育过程中上皮细胞超微结构最显著变化是质体、内质网和嗜锇滴数量的改变,它们随着分泌道的成熟而增加,随着分泌道的衰老而减少,嗜锇物质主要由质体、鞘内质网和细胞质内质网合成,而线粒体、液泡和细胞质也可参与分泌物的合成和运输过程

STUDIES ON THE STRUCTURE AND ULTRASTRUCTURE OF THE SECRETORY DUCTS IN THE LEAF OF ANGELICA DAHURICA DEILS

This peper deals with the structure and ultrastructure of the secretory ducts in the leaf of Angelicadahurica Deils. The secretory ducts in the leaf of Angelica dahrica Deils consist of a layer of epithelialcells encircling a round canal, and they distribute in the parenchyma tissues surrounding the vascularboundles and in the secondary phleom of large leaf veins. Those secretory ducts are schizogenous in ori-gin. The enlargement of the canals mainly depends on the surrounding intervening cells and anticlinaldivisions of the epithelial cells. The electron microscope observations suggest that Golgi bodies may beinvolved in dissolution of the middle lamella in the region of thg future canal cavities by secretion oflytic enzymes into the cell walls in development of the canals. Secretory cells in mature canals containmany plastids and endoplasmic reticulum, most of the plastids are sheathed by endoplasmic reticulum.The changes occuring in ultrastructure of the secretory cells in development of the canals are mainlydue to the changes of palstids, endoplasmic reticulum and osmiophilic droplets in quantity. They in-crease with the maturity of the canals, and decreasa with the senility of them. The osmiophilic sub-stances are produced mainly in plastids, periplastidal and cytoplasmic may be also participate in theprocess of synthesis and transportation of the secretions.