| Polygonum ciliinerve (Nakai) Ohwi was a folk commonly used Chinese herbal medicine, belonging to Polygonum of Polygonaceae. By recordation, its root tuber have been used as medicinal material. The most effective chemical constituent of P. ciliinerve was the total anthraquinones which mainly includes chrysophanol, physcion, emodin and rhein etc. In this study, we investigated the developmental anatomy and structures of different vegetative organs, the localization and accumulation of main chemical component in different vegetative organsa in P. ciliinerve, using paraffin sectioning, histochemistry and phytochemistry methods. Otherwise the systematic position of Ploygonum ciliinerve was analyzed.In this paper, some important results were listed hereinafter:The root tip of Polygonum ciliinerve was composed of root cap, meristematic zone, elongation zone and maturation zone. The primary structures of the root consisted of epidermis, cortex and vascular cylinder. Some cells in epidermis and pericyclic parenchyma cells showed red brown, and indicate that these cells contained a lot of inclusions. The secondary structure of root was composed of periderm, pericyclic parenchyma cells, secondary vascular tissue and primary xylem from the outside to the inside. The periderm included 3-6 layers of cork cells whose walls had been suberized and protoplasts had been disaggregated, cork cambium and phelloderm. Inside the periderm there were several layers of pericyclic parenchyma cells that were nearly oblong in shape and arranged loosely with intercellular spaces. The secondary vascular tissues consisted of secondary phloem, vascular cambium and secondary xylem. The secondary phloem contained fibers, sieve tubes, companion cells, phloem rays and many phloem parenchyma cells, most fibers aggregated into bundles which arranged as a cycle in the periphery of phloem. The type of phloem ray was uniseriate ray. The vascular cambium was ring like. The secondary xylem occupied 1/3 area of the root, the vessels were dispersed among parenchyma cells, and the xylem ray was uniseriate or multiseriate and connected together with phloem ray. The primary xylem of pentarch located in the center of root.The primary structure of stem of Polygonum ciliinerve consisted of epidermis, cortex and vascular cylinder from the outside to the inside. Because the pith developed earlier, its cells were gradually destroyed and developed into an empty cavity as the stem growing. The secondary structure of stem was composed of periderm, cortex, secondary phloem, vascular cambium, secondary xylem, primary xylem and pith. The central pith was destroyed mostly now.The vegetative and reproductive organs of Ploygonum ciliinerve were stem tuber, which was originated from an axillary bud or top bud on the creeping stem, and there were many roots and buds on stem tuber. The primary structures of stem tuber consisted of epidermis, cortex, primary vascular tissue and pith from outside to inside. The mature stem tuber was composed of periderm, cortex, secondary vascular tissue, anomalous vascular bundle, primary xylem and pith from the outside to the inside. The outside of periderm was several layers of deep brown cork cells, the phelloderm was only one layer cells. The cortex consisted of several layers of parenchyma cells that contained lots of calcium oxalate cluster crystals and inclusions. The secondary vascular included secondary phloem, intrafascicular cambium and secondary xylem. In addition, anomalous vascular cambium cells were found to develop in the secondary xylem formed early. The pith area was small in the cross section of stem tuber and its cells contained numerous inclusions.The leaf of Polygonum ciliinerve belonged to typical bifacial leaf and included ocrea, leaf stalk and leaf blade. The cross section of leaf blade was composed of epiderms, mesophyll and leaf vein. A lot of glandular hairs were dispursed on leaf epidermis of both sides and numerous papillose present on both sides of the leaf veins. The transverse sections of main leaf veins and petioles showed 5 and 10 vascular bundles respectively.The flower was bisexual and composed of 8 stamens and 1 pistil. The style was very short and its stigma were three and extended peltate stigma. The fruit was very small and ovate-triangular achene with wings. The pericarp micromorphology of fruit belonged to fovea surface ornamentation. The transverse section of its seed was nearly triangular. Histochemical studies about the total anthraquinones in P. ciliinerve showed that the total anthraquinones in the stem tuber mainly located in cortex, phloem parenchyma, xylem parenchyma, pith and vascular rays. In the root, it was mainly distributed in pericycle and phloem parenchyma. In the stem, it mainly located in cortex and pith that adjacent to xylem. That is to say, the total anthraquinones were mainly distributed in parenchyma cells.Histochemical studies for polysaccharide showed that mounts of starch grains were located in cortex, phloem, cambium, xylem and pith parenchyma cells of stem tuber, providing abundant nutritive material for the bud and adventitious root's germination. There were also mounts of starch grains in root and stem; they located in pericyclic parenchyma cells of root and in cortex and pith of stem.The content of total anthraquinones in P. ciliinerve was determined by spectrophotometric method. From this result we could see that the content of total anthraquinones in the stem tuber was obviously higher than that in the root, stem and leaf. In traditional use of P. ciliinerve in China, the medicinal part was its stem tuber with adventitious roots cut off. According to our experiment, its stem tuber born many downward adventitious roots, furthermore, the content of total anthraquinones in root was 0.31%, which is far higher than that in stem and leaf, therefore, we suggested that the stem tuber with numerous adventitious roots should be used for no waste of resources. On the other hand, the content of total anthraquinones in stem tuber increased as the diameter thickening.The content of emodin determined by HPLC in the stem tuber was also increased as the diameter thickening. While, compared with the stem tuber of diameter of 8 cm, the content of total anthraquinones and emodin in the one of 14 cm showed respectively no obvious increasing. So we suggested that it would be most appropriate to collect the stem tuber as a medicinal material when its diameter was 8-14 cm.Differences regarding the systematic position of Polygonum ciliinerve in Flora of China and the other province Floras were remained. The vegetative and reproductive organs of Ploygonum ciliinerve were observed and the systematic position of Ploygonum ciliinerve was analyzed. The results showed that the main medicinal part of Ploygonum ciliinerve was stem tuber, which was originated from an axillary bud on the creeping stem, but not root tuber. The upper epidermal cells were about oblong; the lower epidermal cells were superficial wavy. Numerous papillose present on both sides of the leaf veins, and a few of glandular hairs were dispursed on leaf epidermis of both sides. The transverse sections of main leaf veins and petioles showed 5 and 10 vascular bundles respectively. Its pericarp micromorphology belonged to fovea surface ornamentation. The transverse section of its seed was nearly triangular. These characteristics of Polygonum ciliinerve were obviously different from those of Polygonum multiflorum. As a result, we suggested that Ploygonum ciliinerve should be treated as a species rather than a variant of Polygonum multiflorum.
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