Ecological Adaptability And Endangered Mechanism Of Paeonia Ludlowii

Paeonia ludlowii,whose living conditions are extremely harsh,is an endemic and endangered plant in Tibet.It is a clump shrub,cold resistant and prefers mild climate.P.ludlowii is mainly distributed in the long and narrow valley from Mirui Township,Nyingchi City to Longzi County,Shannan City.In order to explore its ecological adaptability,this study first investigated and collected the geographical data of different producing areas,and collected soil samples from all wild producing areas to determine the soil physical and chemical properties,detecting soil microorganisms,taking Mirui township as a representative to detect its endophytes,using simplified genome sequencing technology to study the genetic characteristics of the population,and predicted its potential distribution area to explore the adaptation of P.ludlowii to the environment.Then,through seed metabolomics research and seed embryo culture experiment,the endangered system was analyzed laterally.The main results are as follows:1.The soil organic matter content and total nitrogen content in 10 P.ludlowii production areas are very rich,the total phosphorus content is medium,the total potassium content of soil is medium or relatively lacking.The soil alkaline hydrolyzable nitrogen content is very rich,and the content of available phosphorus in soil is abundant or relatively abundant,and quick-acting potassium content is relatively abundant,medium or relatively lacking,the soil fertility of 10 areas is rich,which is suitable for the growth of P.ludlowii,and the P.ludlowii has adapted to the relative lack of soil potassium content.The physical and chemical properties of soil are the main factors affecting soil enzyme activities.The soil physical and chemical properties and geographical characteristics directly affect the differences of soil microbial community structure.In addition,the soil microbial community structure and abundance will change with of the geographical location,physical and chemical properties and soil enzyme activities of the wild population,indicating that the wild population of P.ludlowii is suitable for different species by regulating the community structure and abundance of soil microorganism ecological environment.2.Dothideomycetes and Sordariomycetes is the marker groups of endophytic fungi and rhizosphere soil fungi of P.ludlowii,also have important medicinal value.Therefore,endophytic fungi may have a certain relevance with the medicinal functions of P.ludlowii.Pseudomonas of prebiotics has less content in roots,leaves,flowers and fruits of P.ludlowii,even in stem.Therefore,we predict that due to the low abundance or lack of endogenetic,the resistance to reverse is weak,which may be one of the reasons why P.ludlowii is endangered.3.The genetic structure analysis of the population showed that 10 wild populations of P.ludlowii could be classified into 5 groups,namely,Zhineng village group,Puyu village group,Sananqulin village group,north bank group of Yaluzangbu River and south bank group of Yaluzangbu river.The analysis of population genetic diversity shows that compared with the Shannan group,the Nyingchi group has a higher population genetic diversity,and there is a high level of differentiation between the Shannan and the Nyingchi groups.The group of Nyingchi can improve their adaptability to the environment and enhance their competitiveness in the environment by improving their own genetic diversity.4.In China,the southeastern Tibet,western Sichuan,and a few areas in northern Yunnan were suitable distribution areas of P.ludlowii.The distribution of P.ludlowii in our region is dominated by ecological factors such as isotherm,altitude,average temperature in the coldest season,rainfall in the driest month,clay content in soil,monthly average temperature in November,December and January.5.The main metabolites of de-embryomed seeds of P.ludlowii were flavonoids and phenolic acids,and the contents of benzoic acid and p-hydroxybenzoic acid in seed coat and endosperm were relatively high.Flavonoids,phenolic acids,terpenes and alkaloid metabolites synthesized from the seed coat and endosperm of P.ludlowii may interact with each other to produce autotoxicity and inhibit the germination of its seed embryos,which may lead to the decrease of seed germination rate of P.ludlowii under natural conditions,which may be one of the reasons for the endangerment of P.ludlowii.6.The seed coat and endosperm of P.ludlowii contain allelopathic substances(self-toxic substances)which affected the germination of the seed embryos of P.ludlowii.These substances significantly inhibited the germination of seed embryos through interaction.It was best to raise seedlings and transplant P.ludlowii in the artificial cultivation process.In winter,it is necessary to add suitable water.In summer(rainy season),the field water should be removed timely,regularly add organic fertilizer and weed and loosen the soil,so that artificial cultivation can be realized.