Relationship Between Quality And Ecological Environment And Its Suitable Growth Areas Of Saposhnikovia Divaricata

Saposhnikovia divaricata(Turcz.)Schischk.is a herb of Umbelliferae family.The dried roots without boiting in autumn has been used for many years in China as an important herbal medicine.At present,with the increasing demand for S.divaricata and the uncontrolled digging by human beings,the wild S.divaricata resources are increasingly scarce.Therefore,research on the relationship between the medicinal components and environmental factors and the elucidation of the leading ecological factors affecting the quality of S.divaricata can provide theoretical basis for improving the quality and standardizing the cultivation of S.divaricata.In this paper,the relationship between the content of chromones and soil factors(15 kinds of soil factors)and climate factors(11 kinds of climate factors)in cultivated and wild S.divaricata from different sample areas in order to clarify the effects of ecological factors on the content of medicinal components of S.divaricata.The potential suitable growth areas of S.divaricata were predicted by the Arc GIS system and Maxent model under the current and future climate conditions,and the geographical distribution pattern of S.divaricata under the background of climate change is studied,which can provide theoretical basis for the artificial cultivation and species protection.The main research results are as follows:1.There are significant differences in the contents of prim-O-glucosylcimifugin,cimifugin,5-O-methylvisamminoside,sec-O-glucosylhamaudol and the total contents of4 kinds of chromones between cultivated and wild S.divaricata.The content of prim-O-glucosylcimifugin,cimifugin and the total content of 4 kinds of chromones are all highest in the regions of Xiwuzhumuqin Banner,Xilingol League,Inner Mongolia.The content of prim-O-glucosylcimifugin,cimifugin and the total content of chromones are all lowest in the regions of Longde County,Guyuan City,Ningxia Province.The regions with the highest and lowest content of 5-O-methylvisaminoside are Taonan,Baicheng City,Jilin Province,and Longde County,Guyuan City,Ningxia Province.The regions with the highest and lowest content of sec-O-glucosylhamaudol are Hacha Line,Xilingol League,Inner Mongolia,and Tangjiawopu,Chifeng,Inner Mongolia,respectively.The highest total yield of chromone per plant is in Datun Township,Chengde City,Hebei Province,and the lowest total yield of chromone per plant is in Longde County,Guyuan City,Ningxia Province.The total yield of chromone per plant in Datun Township is 6.6 time higher than that in Longde County,Guyuan City.The content of chromones in wild S.divaricata is mostly higher than that in cultivated S.divaricata,and the total content of 4 kinds of chromones in phloem of S.divaricata root is generally higher than that in xylem.2.The results of correlation analysis showed that there was a significant negative correlation(P<0.01)between the total content of 4 kinds of chromones and p H、conductivity,available phosphorus content and available calcium content in soil,and a significant positive correlation with available zinc content in soil.Multiple linear regression analysis showed that available phosphorus,electrical conductivity and available calcium could explain 72.1% of the total chromone information of S.divaricata.The results of principal component analysis showed that available phosphorus,available calcium and electrical conductivity played a leading role in affecting the chromone content of S.divaricata,and their cumulative contribution rate reached 88.896%.3.The maximum entropy model Maxent and geographic information software Arc GIS are applied to predict the potential suitable growth areas for S.divaricata under climate change and reveal the suitable intervals of key environmental factors affecting its distribution.The results showed that the total suitable growth areas of S.divaricata in China is decreasing from the current real climate to the future climate situation,but the most suitable habitat distribution areas of CCSM4-rcp4.5 and CCSM4-rcp8.5 are increasing under the two future climate situations.The results of calculation and analysis by Maxent model showed that the precipitation of the wettest month,temperature seasonality,reference depth of soil,mean temperature of the warmest season,mean temperature of the driest season are the main environmental factors affecting the distribution and suitability of S.divaricata,which the appropriate interval are that the precipitation of the wettest month are from 50 mm to 600 mm,the coefficient of temperature seasonality are from 400 to 16800,reference depth of soil are from 10 cm to100 cm,the mean temperature of the warmest season are from 2.5 ℃ to 32 ℃,the mean temperature of the driest season from-29 ℃ to 22.5 ℃,respectively.