Studies On Photosynthetic Characteristics,Effective Composition And DNA Barcoding Of 10 Species Of Astragalus L.in Jilin Province

Astragalus L.is a large genus of leguminosae.There are more than 2000 species in the world and 278 species in China.There are 10 species of Astragalus in Jilin Province.Some species of Astragalus are important Chinese medicinal materials in China,such as A.membranaceus Bunge,A.mongholicus Bunge and A.complanatus Bunge,which are authentic Chinese medicinal materials in the《Chinese Pharmacopoeia》.A.membranaceus Bunge and A.mongholicus Bunge are the original plants of Chinese medicine and its root is used as medicine.The seeds of A.complanatus Bunge is a famous traditional Chinese medicine.In addition to the above-mentioned varieties of Chinese medicinal materials included in the《Chinese Pharmacopoeia》,some species are used as local medicinal materials,such as the seeds of A.chinensis L.F..Other species also have other functions and economic values.For example,A.laxmannii Jacquin,A.hsinbaticus P.Y.Fu et Y.A.Chen and A.scaberrimus Bunge can be used as herbage,A.laxmannii Jacquin,A.complanatus Bunge,and A.scaberrimus Bunge can be used to prevent soil erosion.The whole plant of A.chinensis L.F.can be used as feed.There are many species and rich resources of Astragalus L..At present,there are more studies on the plants of Astragalus L.including A.membranceus Bunge and A.mongholicus Bunge,followed by A.complanatus Bunge,while there are few studies on other species.Moreover,in the cultivation practice of Astragalus,the mixture of provenances and the market of medicinal materials is filled with many fake and inferior products,which makes the output and quality of Astragalus unstable,and also can not guarantee the clinical application accuracy and the validity of Astragalus.This paper deals with 10 species of Astragalus in Jilin Province,e.g A.membranceus Bunge,A.mongholicus Bunge,A.complanatus Bunge,A.laxmannii Jacquin,A.scaberrimus Bunge,A.chinensis L.F.,A.melilotoides Pall.,A.angustissimus Bunge,A.dahuricus（Pall.）DC.,A.hsinbaticus P.Y.Fu et Y.A.Chen and the research was carried out on photosynthetic characteristics,medicinal ingredients,nitrogen,phosphorus,potassium and DNA Barcoding.Also the phylogenetic relationships of 10 plant species were discussed by cluster analysis.This study has important theoretical and practical value for the classification and identification of species,breeding of varieties,determination of genetic relationship,development of new medicinal materials and comprehensive development and utilization of resources of Astragalus L..The main findings are as follows:1.Photosynthetic characteristics and their correlation:The results showed that the transpiration rate（10.31 mol/m²/s、9.84 mol/m²/s）and chlorophyll content（5.50 mg/g、5.66mg/g）of A.mongholicus Bunge and A.membranceus Bunge were the highest,and the net photosynthetic rate of A.mongholicus Bunge（8.39μmol CO₂/m²/s）was also the highest.The highest water use efficiency was found in the leaves of A.scaberrimu Bunge and A.dahuricus（Pall.）DC.（1.49%、1.34%）.There were no significant differences in transpiration rate,stomatal conductance,chlorophyll content and water use efficiency between A.membranceus Bunge and A.mongholicus Bunge.The photosynthetic characteristics of A.membranceus Bunge and A.mongholicus.Bunge were similar.The photosynthetic characteristics of A.hsinbaticus P.Y.Fu et Y.A.Chen and A.melilotoides Pall.were relatively similar.The photosynthetic characteristics of A.chinensis L.F.,A.dahuricus（Pall.）DC.,A.scaberrimus Bunge and A.complanatus Bunge were relatively similar.The results showed that net photosynthetic rate was positively correlated with transpiration rate,and transpiration rate was positively correlated with intercellular CO₂ concentration,and chlorophyll content was positively correlated with net photosynthetic rate.2.Study on the effective components:The contents of astragaloside in the stems and leaves of A.mongholicus Bunge and A.membranceus Bunge were not the highest among 10 species of Astragalus L.,the contents of astragaloside,isoflavone glucoside,total saponin,polysaccharide and total flavone in the roots and stems and leaves were the highest,while the contents of total flavone in the roots of A.complanatus Bunge（0.446%）were the highest and the contents of astragaloside（0.253%）and total saponin（0.432%）in its stems and leaves are also very high,and the contents of astragaloside and isoflavone glucoside meet the requirements of《Chinese Pharmacopoeia》.A.complanatus Bunge was treated with seeds,but its root,stem and leaf had high effective components,so it could be further developed and utilized.The contents of astragaloside in the root of A.angustissimus Bunge and the contents of isoflavone glucoside in the root of A.hsinbaticus P.Y.Fu et Y.A.Chen have reached the standards stipulated in the《Chinese Pharmacopoeia》,and have a certain development potential.The contents of astragaloside in the stems and leaves of A.dahuricus（Pall.）DC.（0.158%）and A.chinensis L.F.（0.131%）were higher,while the contents of total saponins in the roots of A.melilotoides Pall.（0.037%）,A.angustissimus Bunge（0.033%）,A.scaberrimus Bunge（0.023%）and A.chinensis L.F.（0.020%）were higher,The content of total saponin in the root of A.laxmannii Jacquin（0.470%）was higher and leaves of A.scaberrimus Bunge（0.440%）,A.hsinbaticus P.Y.Fu et Y.A.Chen（0.437%）and A.chinensis L.F.（0.390%）were higher,and the contents of total flavonoids in the stems and leaves of A.angustissimus Bunge（1.255%）and A.scaberrimus Bunge（0.983%）were higher.From the whole pharmacodynamic composition,the following groups are similar:A.mongholicus Bunge and A.membranceus Bunge,A.complanatus Bunge and A.dahuricus（Pall.）DC.,A.angustissimus Bunge and A.scaberrimus Bunge,A.hsinbaticus P.Y.Fu et Y.A.Chen and A.melilotoides Pall..3.Study on N,P,K contents:The contents of N,P,K in stems and leaves of A.laxmannii Jacquin and A.hsinbaticus P.Y.Fu et Y.A.Chen were almost the same as those of A.hsinbaticus P.Y.Fu et Y.A.Chen and A.melilotoides Pall..4.DNA barcoding and cluster analysis:The results of 10 species plant based on the four DNA Barcodes（ITS2,matk,rbc L and psb A）showed that,the ITS2 sequence is relatively good.The result of cluster analysis is consistent with the classification of 10 species of Astragalus L.in the《Flora of china》.