Study On The Accumulation Of Saponins In Different Growth Stages Of Panax Notoginseng

Panax notoginseng(Burk)F.H.Chen is one of the rare Chinese traditional herbs.In recent years,with the rapid development of the P.notoginseng industry and continuous cropping obstacles in the P.notoginseng cultivation,the resources of land have became tense.As a result,the planting areas of P.notoginseng had continued to expand beyond the Wenshan.However,there were little researches about the growth stages and the content of saponins.Therefore,we selected four experimental sites for P.notoginseng planting in Yunnan Province to study the condition of growth and saponins accumulation of the three-year-old P.notoginseng at the vegetative stage,full-bloom stage and the harvest stage.The result can provide scientific guide for the introduction of P.notoginseng.This study is depended on the P.notoginseng at the vegetative stage,full-bloom stage and harvest stage,which were basically with the same cultivation and management,the experimental sites including Yanshan Wenshan(Site 1),Shilin Kunming(Site 2),Tangdian Kunming(2160 m)(Site 3)and Tangdian Kunming(2380m)(Site 4).The contents of research included nine biological characters,the contents and activities of five physiological indexes in the leaaves,the contents of total saponin and four monomer saponins in the main root and rhizome at different growth stages,and the contents of soil nutrient elements at the harvest stage.The differences of phenotypic biological characters,physiological indexes and saponins content in main root and rhizome of P.notoginseng in different experimental sites were compared.The correlations between these indicators and the content of monomer saponins and total saponin in the main root and rhizome were analyzed.The main results are as follows:(1)In the vegetative stage,nine phenotypic biological traits of P.notoginseng have significant differences among the four experimental sites.The phenotypic value of the biological traits and the contenet of total saponins in the rhizome was the lowest in Site 1,while the content of total saponins in the main root was the highest.In addition to plant height,the other 8 phenotypic biological characters were significantly negatively correlated with the contents of four monomer saponins and total saponins in the main root,but were significantly and positively correlated with the contents of monomer saponins and total saponins in the rhizome.(2)In the full-bloom stage,nine phenotypic biological characters of P.notoginseng were significantly different among the four experimental sites.The phenotypic value of Site 3 was the largest,but the content of total saponins in the main root and rhizome was the lowest;While the phenotypic value of Site 1 was the lowest,but the content of total saponins in its rhizome was the highest.There was a positive correlation between the stem width and the content of the saponins in the rhizome,and the other eight phenotypic biological characters were negatively correlated with the content of the four monomer saponins and total saponins in the main root and rhizome.(3)In the harvest period,there were significant differences among the nine phenotypic biological characters of P.notoginseng in the four experimental sites.The phenotypic value of Site 3 was the largest,but the content of total saponins in the main root and rhizome was the lowest;while the phenotypic value of Site 1 was the lowest but the content of total saponins in its main root and rhizome was the highest.The nine phenotypic biological characters were significantly and negatively correlated with the contents of four monomer saponins and total saponins in the main root and rhizome of P.notoginseng.In addition,soil organic matter,total nitrogen and total phosphorus were negatively correlated with total saponins in main root and rhizome,while total potassium and slow available potassium were positively correlated.Conclusion:From the vegetative stage,full-bloom stage to harvest stage,the phenotypic value of the biological characters of three-year-old P.notoginseng gradually increased,and the biomass was negatively correlated with the content of saponins.With the growth period,the total root saponins in P.notoginseng were observed.Thecontent showed the trend of decreasing first and then increasing,and the content of vegetative stage was the highest;However,the total saponin content in the rhizome was increased and the content of vegetative stage was the lowest.