【作者】 刘世彪；

【导师】 胡正海；

【作者基本信息】 西北大学 ， 植物学， 2005， 博士

【摘要】 绞股蓝[Gynostemma pentaphyllum(Thunb.)Makino]隶属于葫芦科绞股蓝属绞股蓝亚属,为多年生草质藤本植物,主产于热带亚洲、中国、朝鲜和日本。全草均具有药用价值,主要的药用成分为绞股蓝皂甙。本文在对绞股蓝的分类系统和资源分布、形态结构、生长发育和生理生态特性、化学成分、药理作用、综合开发利用,以及繁殖和栽培技术等绞股蓝研究报道进行综述的基础上,采用植物解剖学、组织化学和植物化学等技术相结合的方法研究了绞股蓝根、茎、叶的结构和发育及其与皂甙类物质积累部位和含量变化的关系,进行了绞股蓝属6个种的结构与皂甙含量的比较。应用植物生理、生态学方法,研究了遮荫对绞股蓝叶形态结构、光合特性和皂甙含量的影响,完成了湖南省西北部两个样地野生绞股蓝属的群落学调查,研究结果如下。 绞股蓝的叶为异面叶,有栅栏组织和海绵组织的分化,叶中脉具1个维管束,叶柄5个维管束。茎由表皮、皮层和维管柱构成,双韧维管束9个,在基本组织中排成2轮,周维管纤维连续成1圈,但在根状茎中断裂,根状茎具次生结构。幼根木质部2～4原型,老根由维管组织和周皮构成。超微结构中发现筛管细胞中有囊泡进行物质转运,但与同化组织和韧皮薄壁细胞一样,其中未见与皂甙类物质有关的特殊电子致密物或嗜锇颗粒。 绞股蓝营养器官的组织化学定位表明,人参皂甙遇特定的显色剂能出现从浅红到紫色的颜色变化,可以此来确定人参皂甙的积累位置和含量多少。试验表明其叶肉的栅栏组织和海绵组织中含有皂甙,组织分化不明显的幼叶比分化成熟的叶积累皂甙多,衰老的叶片不积累皂甙。茎的同化组织、外生韧皮部含皂甙较多,表皮、厚角组织含皂甙较少,而木质部和髓薄壁组织无皂甙积累,幼嫩组织也比成熟组织积累多。皂甙还存在于根状茎的次生韧皮部和栓内层中。叶和茎的表皮毛和腺毛中更多还原

【Abstract】 Jiao-Gu-Lan [Gynostemma pentaphyllum (Thunb.) Makino], which belongs to Subgen. Gynostemma, Gynostemma, under Cucurbitaceae, is a perennial climbing herbal liana growing wild throughout tropical Asian, China, Korea and Japan. Gypenosides are the major medicinal components that are extracted from the leaf, stem, rhizome and root of this herb.After reviewing systematics, distribution, morphorlogy and structure, growth and development, physiology and ecology, chemical component, pharmacology, medical exploitation and comprehensive use, the technique of propagation and cultivation, we investigated the structure of the vegetative organs of G pentaphyllum and its correlation with medical components by using anatomy, histochemistry and phytochemistry. The structure and content of total gypenosides among 6 species of Gynostemma were also compared. By using physiological and ecological methods, the changes of leaf morphology, structure and photosynthetic characteristics, and gypenosides content under different shading treatment were described, and the coenology features of wild Gynostemma in two plots in Northwest Hunan province were investigated.The leaf of G pentaphyllum was bifacial, with distinct differentiation of palisade tissue and spongy tissue, and there was a single vascular bundle in mid rib, 5 vascular bundles in leaf stalk. The transverse section structure of stem was composed of epidermis, cortex and vascular cylinder. 9 bicollateral vascular bundles arranged in 2 rings were separated from one another by broad strips of ground tissue. There was a continuous ring of perivascular fibrous cells in the pericycle of stems, but this may become discontinuous in rhizomes. The rhizome had secondary structure. Primary xylem in young rootwas diarch, triarch or tetrarch, then second structure existed in old root.Ultrastructures were studied by transmission electron microscope. There was substance translocation in the sieve elements by some bubbles, but no evidence confirmed whether these substances in bubbles were gypenosides or not, for no special electron density bodies or osmiophilis granules related to gypenosides were seen in sieve elements, as did in assimilating tissue and phloem parenchyma.Histochemistry test in the vegetative organs showed that vanillin-acetic acid and perchlorid acid (1:1) reacted with ginsenosides-like substance to produce characteristic colors, from light red to purple. We used it as a test reagent to locate gypenosides and deduce its contents. Gypenosides were stored in palisade tissue and spongy tissue in leaf, the undifferentiated assimilating tissues appeared redder than the mature ones, and the effete leaf accumulated no gypenosides. The assimilating tissue, external phloem contained more gypenosides than epidermis and collenchyma, while the xylem and pith parenchyma contained no gypenosides. Epidermal hair and glandular hair had gypenosides also. The younger the organs were, the redder they developed. In rhizome and old root, gypenosides accumulated in secondary phloem and phelloderm.The contents of total gypenosides changed with seasons in a growth period. It showed a changing trend from low to high, then to low, during the period from vegetative growth, florescence and fructescence to withering. It was lowest in June, increased from July to September, reached the highest value in October, and dropped in November to the value of July to August. The content of total gypenosides in rhizome was significant higher than that in leaf and stem, leaf was higher than stem, younger organs were higher than older ones, male was higher than female. The total yield of gypenosides of tetraploid was higher than that of diploid. It was suggested that cultivating tetraploid G pentaphyllum and male plants more, harvesting the aerial parts only, and remaining the rhizome and root in florescence and fructescence (Sept. to Oct.) was of benefit to improving both herbal quality and quantity, and accelerating the sustainable utilization of wild resources.The structure features of stem and leaf of 6 species of Gynostemma were similar, with quantity difference in anatomic index, but no specific propertyto species. There was no significant correlation between the contents of total gypenosides and the structure index including the ratio of thickness of epidermis and cortex to stem diameter, palisade tissue to spongy tissue, vascular bundle area to stem area, external phloem area to stem area. G guangxiense, G. pentaphyllum, G cardiospermum and G. laxum had higher contents of total gypenosides than G. longipes and G. pentagynum did.The daily patterns of net photosynthetic rate (Pn) appeared as double-peak curves. The peak values appeared at 11:00 am. and 17:00 pm. There was a distinct phenomenon of "noon break" under strong light and high temperature. G pentaphyllum is a species of sciophiles. The leaf morphology and structure were largely affected by light intensity. Under shading treatments, the leaf featured with large size, dark green, thin thickness of leaf blade, palisade tissue and spongy tissue, and undeveloped vascular bundles compared with those under full sunlight. Meanwhile, the contents of chlorophyll and net photosynthetic rate under shading treatment were higher than those under full sunlight, while the contents of total gypenosides showed a reverse trend to the former. Shading treatment could accelerate the growth and development of G. pentaphyllum, thus increase the field yield and total gypenosides.There are 3 species of Gynostemma in Northwest Hunan province, including G pentaphyllum, G. laxum and G. pentagynum, all growing in shady and moist mountainous environment. Ficus heteromorpha, Camellia candata and Weigela japonica var. smica were mainly trees shading the community. The concomitant community of Gynostemma consisted of 158 species, 134 genera, 70 families of vascular plants, showing a higher index of diversity. Chrysosplenium lanuginosum and G pentaphyllum, as well as G. pentagynum and Artmisia lavanduaefolia were dominant species in the concomitant community of G. pentaphyllum and G. pentagynum respectively. Pilea notata was an important companion species for G pentaphyllum and G pentagynum.更多还原