【摘要】 应用植物解剖学、组织化学定位及植物化学技术,研究了栽培太子参块根不同发育时期的结构特征与皂苷积累的关系。结果表明:太子参不定根的初生结构和次生结构类似一般草本双子叶植物根的特征。在成熟的块根中次生木质部约占80%,其中以木薄壁组织细胞为主,导管很少,次生韧皮部中也以薄壁组织细胞居多,从而形成纺锤状块根。组织化学定位显示,在根的初生结构中,皂苷分布在中柱鞘和初生韧皮部的薄壁组织细胞中。在次生结构与成熟块根中,皂苷分布在除木栓层及导管外的周皮及次生维管组织其它细胞中,其中次生韧皮部显色较深。植物化学检测结果表明,2月与7月块根的皮部中皂苷的含量高于木部,与组织化学结果一致;根头部的皂苷含量>根尾部>根中部。在块根的发育过程中,皂苷的含量存在高-低-高的动态特点,此种变化规律与其根系的发育特点相关。更多还原

【Abstract】 Anatomical,histochemical and phytochemical methods were used to investigate the structure,the localization and content changes of total saponin of the root tuber of Pseudostellaria heterophylla on different developmental stages.Results showed that the primary structure and sec-ondary structure of P.heterophylla adventitious root were similar to that of other herbaceous di-cotyledons.80% of mature root tuber were secondary xylem which consisted of most parenchyma cells and less vessels.The secondary phloem were composed of parenchyma cells too.The results of histochemical methods showed that saponin distributed in pericycle and parenchyma cells of primary phloem in the primary structure of root.In secondary structure and mature root tuber,saponin distributed in periderm and secondary vascular structure except cork layer and vessel.Be-sides,the colors of the secondary phloem were darker.The results of phytochemical test showed that the content of saponin in skin areas was higher than that in xylems in February and July.The result was consistent with that of histochemistry.The content of saponin in the head of the root was higher than that in the end of the root which was in turn higher than that in the mid-dle part of the root.In the developmental process of root tuber,the content of saponin showed a dynamic tendency of high-low-high.This characteristics were related to the development of root system.更多还原