绞股蓝营养器官各发育阶段结构与总皂甙含量相关性的研究

应用组织化学定位技术及植物化学方法，研究了不同发育阶段绞股蓝茎叶的结构与其中人参皂甙分布积累和总皂甙含量的关系。绞股蓝内的人参皂甙通过特定的显色剂能显示从紫红到浅红的颜色反应，颜色深浅与人参皂甙含量呈正相关。结果表明，叶内的皂甙主要分布在叶肉组织内，未分化的叶肉组织比成熟组织含量高，衰老的叶片不含皂甙。茎内的皂甙主要分布于维管束的外生韧皮部薄壁细胞中，表皮、同化组织、厚角组织及周皮的栓内层也有少量分布，木质部和髓薄壁组织无皂甙积累；幼茎所含总皂甙高于发育成熟的茎和老茎，含量最高的则是具有贮藏功能的根状茎。在绞股蓝全草中，叶的总皂甙含量高于相应发育阶段的茎，而以当年生根状茎的含量最高。提出了皂甙在叶内积累、茎内运输和地下茎内贮藏的观点及科学采收绞股蓝的建议。

Correlation Studies on the Structure and the Contents of Gypenosides in Vegetative Organs of Gynostemma pentaphyllum in Different Developmental Stages

Histochemistry technique and phytochemistry methods were applied in the studies on the relationship between the structure where ginsenosides accumulated and the contents of total gypenosides in stem and leaf of medicinal plant Gynostemma pentaphyllum in different developmental stages.The results indicated that ginsenosides appeared color reaction from purple to light red when met special chromogenic agent, and the shade of color showed a positive correlation to the contents of ginsenosides in vegetative organs.In terms of leaf,ginsenosides distributed mainly in mesophyll tissue,the contents was higher in undifferentiated mesophyll than that in mature (tissue), while the effete leaf contained no ginsenosides. As to stem, ginsenosides distributed mainly in the external phloem parenchyma cells, much less in epidermis, assimilating tissue, (collenchyma) and phelloderm, and no coloration in xylem and pith parenchyma. The younger stem had a higher content of total gypenosides than that of mature and older stem, while rhizome,the storage organ, had the highest content. Within a plant, the accumulation of total gypinosides in the leaf occupied first place, the stem came second, and the current rhizome the highest in the same developmental stage. The idea that gypenosides accumulated in leaf, translocated in stem and storaged in rhizome and the suggestion of harvest were put forward in this paper.