Identification Gene Barcode And Climate Ecological Suitability Of Trichosanthin

Trichosanthin is the Trichosanthes kirilowii Maxim root or Trichosanthes rosthornii Herms root of the cucurbitaceae.At present,Trichosanthin is widely used in the Chinese medicine market,but its quality is uneven.In order to better develop and use Trichosanthin resources,and provide quality reference for the identification of trichosanthin and the cultivation of towers,this article conducts research on Trichosanthin based on the scientific and technical problems existing in the existing quality standards of trichosanthin providing a theoretical basis for better use of trichosanthin resources.The main contents and conclusions are as follows:1.Identification of Trichosanthin DNA Barcode.In this study,the ITS2 sequence and psb A-trn H sequence were used to identify Trichosanthin and its adulterants,and the samples were abundant,which enriched the identification methods of Trichosanthin,and then provided reference for the identification of other medicinal plants.By collecting 11 copies of Trichosanthin from different regions and 3 adulterants of Trichosanthin,the ITS2 and psb A-trn H sequences were used to analyze the DNA barcode.The results showed that the amplification efficiency of Trichosanthin and its adulterants reached 94%.The minimum K2 P distance between ITS2 and psb A-trn H sequences was greater than the maximum K2 P distance within Trichosanthin species.It can well distinguish Trichosanthin and its adulterants.The results of the constructed NJ tree showed that samples from various sources of the ITS2 sequence and the psb A-trn H sequence could be clustered into a large class,and adulterants,such as king melon root,clog root,andcassava,which formed a class respectiveiy.The samples of Trichosanthin from different areas were grouped into one big group,which was divided into two small branches.Therefore,for the identification of Trichosanthin,an identification method based on the ITS2+psb A-trn H sequence can be constructed.2.The relationship between the active ingredients of Trichosanthin and climatic factors.In this study,the extraction methods were acetone fractionation to extract TCS,water extraction and alcohol precipitation extract Trichosanthin polysaccharides and ethanol extract Trichosanthin saponins,the content determination method was determination of TCS by Coomassie Brilliant Blue,determination of Trichosanthin polysaccharides by Anthrone-Sulfuric Acid and determination of Trichosanthin saponins by vanillin-oleanolic acid,correlation analysis between climate factors and the effective components of Trichosanthin.The results showed that there were significant differences in the content of active ingredients in Trichosanthin from different regions.The TCS was significantly positively correlated with the annual average temperature,the January average temperature,and the extreme lowest temperature,and had no correlation with the July average temperature and the extreme highest temperature.The Trichosanthin polysaccharide was significantly positively correlated with the annual average temperature,the January average temperature,and the extreme lowest temperature,and positive correlation with the extreme highest temperature,and no correlation with the July average temperature.The Trichosanthin saponin significantly positively correlated with the annual average temperature,the January average temperature and the extreme lowest temperature,and positively correlated with the July average temperature and the extreme highest temperature.The contents of TCS,Trichosanthin polysaccharides and Trichosanthin saponins were positively correlated with relative humidity and precipitation.The content of active ingredients in Trichosanthin was negatively correlated with latitude,longitude and sunshine hours,and positively correlated with altitude.This study can lay the foundation for selecting suitable planting conditions and improving the quality ofTrichosanthin.3.Study on the Climate Ecological Suitability of Trichosanthes kirilowii Maxim.With the help of GIS technology and Max Ent model,the maps of the contemporary and future suitable ecological distribution area of Trichosanthes kirilowii Maxim were obtained.The results showed that the distribution area of contemporary Trichosanthes kirilowii Maxim covers most of central and eastern China,and the most suitable areas were mainly distributed in the lower reaches of the Yangtze River,the Huaihe River,the North China Plain,and most of the Sichuan Basin.However,under the influence of three climate scenarios of future greenhouse gas emissions,RCP2.6,RCP4.5,and RCP8.5,the suitable area of Trichosanthes kirilowii Maxim in varying degrees and became scattered.There was a trend toward "eastward contraction" and "southern contraction",and the most suitable areas were concentrated in most areas of the middle and lower reaches of the Yangtze River plain and parts of the Sichuan Basin.And under the influence of climate change,the Trichosanthin saponin is relatively high in the most suitable area and suitable area,but there is no correlation with between the content of TCS and Trichosanthin polysaccharide.In order to ensure the quality and realize the modern production of Trichosanthin,we should increase the propaganda of rational planting and choose suitable planting conditions of Trichosanthes kirilowii Maxim.