| Dioscorea zingiberensis C. H. Wright, which belongs to Sect. Stenophora Uline of Dioscorea in Dioscoreaceae, is a perennial twisted herbal liana. And its main component of medicine is diosgenin. It became an important resource plant of steroid hormone since nineteen forties when diosgenin, can be used to synthesize contraceptive and steroid hormone, was found abundant in rhizome of Dioscorea. And then many researches were made on Dioscorea from many aspects.We have a review of the researches in the first about systematics, distribution and resources, physiology and biochemistry, isolation and identification of chemical component, medical exploitation and comprehensive use.In this dissertation we investigated the structure, the morphogenesis of rhizome of D. zingiberensis and its relationship with medical component by using anatomy, phytochemistry, histochemistry, light and electronic microscopy. And the roles of morphogenesis, storage position and the accumulation trends of diosgenin, and the relationship of ultrastructure of cells accumulate diosgenin with dynamic trends of diosgenin accumulation were discussed.The transverse section structure of rhizome of D. zingiberensis is composed of periderm, ground tissue and vascular bundle scattered among the ground tissue.The protective tissue is composed of periderm, outer remaining epidermis andparenchyma cells.Ground tissue, which is inner of periderm and there is vascular bundle scattered in it, lack of cortex and pith differentiation. Ground tissue on the transverse section can be divided into two regions: outer region and inner region. Outer region is near periderm about 15-18 layers of cells. The cells in this region are small, different in volume, and are in round shape. In the middle of this region, scattered mucous cells with crystal in it and it is arranged in discontinuous circle. In this region it is characterized by no vascular bundle scattered in it. The inner region is in the inner side of the outer region, it covers about 90% of the transverse section area, and the vascular bundle of the rhizome is scattered in. The cells of the ground tissue of this region are parenchyma, and are bigger in volume than that of outer region's cell.Vascular bundle is scattered in the inner region of the rhizome. There are two kinds of vascular bundles: In the outer side of the inner region scattered smaller vascular bundles, which arranged in two irregular circles; and in the center part of inner region scattered bigger vascular bundles, which is 230 v m width, 350 u m long. The vascular bundle belongs to closed vascular bundle and is composed of primary xylem and primary phloem. The vascular bundle is wrapped by vascular bundle sheath whose cells are of thick-walled cell.Wrapped by several lepises vary in size, the apical point of the rhizome protrudes, and is composed of one regular arranged layer of tunica on surface and a mass of corpus under the tunica.Primary meristem that is differentiated under the promeristem is composed of protoderm, ground meristem and procambium.Protoderm is one cell layer, it become protective tissue when it differentiates into epidermis and its cell wall makes corkification.Ground meristem is under protoderm, its center area has cells with thicken cytoplasm where procambium is developed and big vascular bundle is going to be formed there. Ground meristem out side the center, where procambium is notdeveloped, its cell's vacuolization is evident and staining is light. And In the middle of this region, mucous cells with crystal in it are differentiated and it is arranged in discontinuous circle. Also procambiums are initiated as well in this region 570 u m far from apical meristem, and it differentiate into small vascular bundles. At the edge of the ground meristem, the cells are comparatively small and arranged in several lines; it is primary thickening meristem. The primary thickening meristem is active in periclinal division and gives rise to many parenchyma cells, which can also proceed division, and this makes th...
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