Studies On The Anatomy Of Vegetative Organts And The Accumulation Of Medical Component In Polygonum Cuspidatum

The plant Polygonum cuspidatum Sieb. et Zucc. belongs to Polygonaceae, its root and rhizome have been used in traditional Chinese medicine. In this study, the developmental anatomy of rhizome and the structure of vegetative organs in Polygonum cuspidatum were done with the paraffin method. The content of the seasonal change of anthraquinone in vegetative organs of Polygonum cuspidatum and the content of polydatin in different vegetative organs and in different season of Polygonum cuspidatum were determined.The result showed that the primordial meristem at the tip of rhizome was surrounded by 4~7 bud scale. The differentiation of the cells derived from the primordial meristem formed protoderm, ground meristem and procambium strand. Afterwards, the primary structure of the rhizome was formed after the formation of epidermis, ground tissue and vascular bundle differentiated from primary meristems respectively. The interfascicular cambium was inconspicuous and the pellogen derived from the parenchyma of cortex, which formed pellem outward and phelloderm inward.The biennial rhizome of Polygonum cuspidatum was composed of there parts: The periderm, the cortical layer and the vascular cylinder. The periderm was the secondary protective tissue of the rhizome, and was composed of pellem, pellogen and phelloderm. The cortical layer was composed of parenchyma cells, in which there are fiber bundles. The vascular cylinder was composed of the vascular bundle,the rayand the pith. The vascular bundle was collateral vascular bundle with conspicuous fascicular cambium, narrower phloem and wider xylem. The vascular bundle had no vascular bundle sheath and there were the ray parenchyma 2~9 tiers between two vascular bundles.The stem of Polygonum cuspidatum was composed of there parts: the epidermis, the ground tissue and the vascular bundle. Its pith was empty.The leaf of Polygonum cuspidatum was dorsiventral and stomata was usually confined to the hypoderm.The hairs were stiff peg-like non- glandular hairs, which were scare. Calcium oxalate cluster crystal was numerous in sclerenchyma in leaf and petiole. There were four vascular bundles in midrib .Vascular bundles of the veins accompanied by sclerenchyma towards outward surface. There were several vascular bundles in transverse section through the petiole, a large one and seven small ones.The content of free anthraquinone and total anthraquinone of the rhizome, leaf and stem in Polygonum cuspidatum were determined by differential spectrophotometric method. In a whole growth season, the seasonal change of total anthraquinones was inconspicuous. The anthraquinone cumulated maximally in the perennial rhizome and the followed was successively annual rhizome, young leaf, mature leaf, young stem and old stem. The content of free anthraquinone in perennial rhizome was the highest in July and September and the lowest in August, the content of free anthraquinone in annual rhizome, young leaf, young stem and old stem were higher in July than ever. It was suggested that the young leaf of Polygonum cuspidatum is in further exploitation because of the higher content of the anthraquinone.The content of polydatin of the rhizome, leaf and stem in Polygonum cuspidatum were determined using HPLC. The polydatin cumulated maximally in the perennial rhizome and the followed was successively annual rhizome, young leaf and bud, then mature leaf, young stem, old stem and flower. The content of polydatin in perennial rhizome and annual rhizome were the highest in October and November, the content of polydatin in young leaf and bud were the highest in April and May, old leaf, young stem, old stem and flower were low in a whole growth season. It was suggested thatthe young leaf and nud oi Polygonum cuspidatum were in further exploitation.