Ecological Suitability Regionalization Of Bupleuri Radix In The Hebei Province

Bupleuri Radix is identified in the 2015 edition of Chinese Pharmacopoeia as the dried root of Bupleurum chinense DC.or Bupleurum scorzonerifolium Willd..Based upon their different characteristics,they are called “North Bupleurum” and “South Bupleurum”,respectively.Bupleuri Radix functions to reconcile exterior and interior,disperse stagnated liver qi for relieving qi stagnation,ascend yang qi,etc.Its primary active ingredients are saikosaponins and volatile oil.Saikosaponins are the standard of quality inspection as Bupleuri Radix.Modern pharmacological studies have shown that saikosaponins have various effects as a sedative,analgesic,anti-inflammatory,liver-protecting and anti-tumor factor.The pharmacological activities of saikosaponin a and d are stronger.Bupleuri Radix is the traditional Chinese herbal medicine from the Hebei Province.B.chinense DC.is the main variety of Bupleuri Radix from Hebei Province,and it is also called Hardwood Bupleurum or Jin Bupleurum.Because the demand for Bupleuri Radix has increased,cultivation of Bupleuri Radix has increased in Hebei Province.However,the quality of Bupleuri Radix is closely related to the ecological environment in which it is grown.Hebei Province is a vast territory with a complicated geography.From north to south and east to west,the terrain varies in height.The obvious regional differences are complemented by a mild climate.These environmental factors result in Bupleuri Radix cultivation being focused in Hebei Province.There are considerable differences in the quality of Bupleuri Radix produced in different areas.Therefore,we conducted a cultivation suitability analysis on the topography,climate,and soil in Hebei Province.We identified a relationship between the saikosaponin content in the plant and the environment.This study will help ensure that Bupleuri Radix cultivation occurs in the proper locations to maintain an excellent and stable plant quality.Objective: After sampling 43 habitats from Hebei Province,we used high performance liquid chromatography(HPLC)to measure the content of saikosaponin a and saikosaponin d as indicators for quality control.This is in accordance with the 2015 edition of Chinese Pharmacopoeia.The relationship between the content of saikosaponins and the ecological environment was analyzed using a spatial analysis technique.Next,we examined the topography,climate,and soil conditions of the areas in Hebei Province where the plant is grown in order to examine the relationship between saikosaponin content and the environment in an effort to provide a basis for B.chinense DC.cultivation.Methods:1 Sampling: We collected 43 samples of B.chinense DC.from Hebei Province.The harvest date was August and September,2016 and the harvest site was the dry root.2 Measurements of the content of saikosaponin a and d: The concentrations of saikosaponin a and saikosaponin d in B.chinense DC.were determined by high performance liquid chromatography(HPLC).3 Examine the topographical,climatic,and edaphic factors for the suitability regionalization of B.chinense DC.:(1)Maximum entropy modeling: The geographical information from 43 sampling points in Hebei Province,the national three topographical factors data,nineteen climatic factors and eight edaphic factors were identified.Then,according to these factors,we used the maxent to calculate habitat suitability of B.chinense DC.(2)Examine the topographical factors of suitability regionalization for Bupleuri Radix: We used SPSS21.0 to perform a correlation analysis for the saikosaponin contents,altitude,slope and aspect.We used ArcGIS to regionalize Bupleuri Radix according to the suitability of topographical factors.(3)Examine the climatic factors of suitability regionalization of Bupleuri Radix: We used SPSS21.0 to perform a correlation and stepwise regression analysis of climatic factors.We selected the dominant climatic factors that impacted the content of saikosaponins,and analyzed the effect of the climatic factors.We used ArcGIS to regionalize Bupleuri Radix according to the suitability of climatic factors.(4)Examine the edaphic factors for suitability regionalization of Bupleuri Radix: We used SPSS21.0 to perform a correlation analysis for saikosaponin contents,acidity,alkalinity,soil cation exchange capacity,soil sediment concentration,soil clay content,soil subclass,available water content in the soil,soil texture classification,and organic carbon content.We analyzed the effect of these edaphic factors.We used ArcGIS to regionalize Bupleuri Radix according to the suitability of edaphic factors.Results:1 Measurements of the content of saikosaponin a and d: The content of saikosaponin a was 0.639 mg/g~2.658 mg/g.The content of saikosaponin d was 0.584 mg/g~2.482 mg/g.2 Determine the topographical,climatic,and edaphic factors affecting suitability regionalization of Bupleuri Radix:(1)Maximum entropy modeling: We used Maxent to compute topographical,climatic,and edaphic factors separately.This was performed 1,000,000 times.We selected three topographic factors,eight climatic factors,and five edaphic factors that had the greatest effect on Bupleuri Radix habitat suitability.(2)Determine the topographical factors of suitability regionalization for Bupleuri Radix: When the altitude was greater than 600 m,the content of saikosaponins was the highest.When the altitude was less than 200 m,the content of saikosaponins was the lowest.When the slope was 4.0~5.5°,the content of saikosaponins was the highest.When the slope was less than 2.5°,the content of saikosaponins was at its lowest.(3)Determine the climatic factors of suitability regionalization of Bupleuri Radix: Statistically significant climatic factors obtained after stepwise regression analysis were the wettest season average temperature and isothermal properties.When the wettest season average temperature was less than 21°C,the content of saikosaponins was the highest.When the wettest season average temperature was greater than 23°C,the content of saikosaponins was at a minimum.When the isothermal property was 30~31,the content of saikosaponins was highest.When the isothermal property was 26~27,the content of saikosaponins was at a minimum.(4)Determine the edaphic factors of suitability regionalization of Bupleuri Radix: The results showed that there was no correlation between edaphic factors and the saikosaponin content.Conclusion:1 This research indicates that the most suitable topographical and climatic conditions for the cultivation of Bupleuri Radix are as follows: altitude of 600 m high,slope of 4~5.5°,aspect to the sun,a wettest season average temperature of 21°C below,and an isothermal property of 30~31.2 The most suitable areas to cultivate Bupleuri Radix were the Taihang Mountains and the Yanshan Mountains,including western Handan,Shijiazhuang,Baoding,Tangshan,Qinhuangdao,and most areas of Zhangjiakou and Chengde.In order to ensure cultivation of high-quality Bupleuri Radix,these environmental conditions should be selected for.3 This topic examines the cultivation of Bupleuri Radix in Hebei Province in order to ensure quality production of this plant.The ecological suitability regionalization of Bupleuri Radix should be studied further in the future.