Studiers On Genetic Diversity And Chemical Diversity Of Dictamnus Dasycarpus Turcz.

Dictamnus dasycarpus Turcz.is a perennial herb of the genus Dictamnus in the Rutaceae family.Its dried root bark is used as medicine to treat damp-heat sores,dripping yellow water,and eczema.It is a traditional Chinese herbal medicine.It has a wide range of uses in medical,medicinal,ornamental and other fields.However,in recent years,due to excessive excavation and destruction of in situ,its wild resources are scarce.Artificial cultivation is an effective way to solve the source and development of medicinal materials.Understanding and mastering the genetic diversity of its germplasm resources is the basis for artificial cultivation of new varieties.However,the research in this area has not yet been systematically reported.For clear germplasm genetic diversity characteristics,therefore,this study collected 32 origin Dasycarpus as material,used ISSR molecular marker technology combined with chemical fingerprint,to parse the dasycarpus DNA genetic structure,chemical composition characteristics,biological activity and genetic relationship.The main findings are as follows:(1)ISSR molecular markers showed that Dasycarpus has a moderate to low degree of genetic diversity at the population level,and the genetic variation mainly comes from within the population.UPGMA clustering had a high consistency with the principal coordinate analysis results,which can distinguish the cultivated populations of Dasycarpus from the wild populations,and had a certain correlation with geographic distance.When the genetic consistency was about 0.85,the Dasycarpus could be clustered into four clusters: the Ⅳ cluster included the wild populations from Jilin,Liaoning and a few from Inner Mongolia;cluster III consists entirely of Inner Mongolia populations;Cluster Ⅱ was composed of cultivated population and wild population in Heilongjiang Province,indicating the origin of cultivated germplasm.ClusterⅠhas only a single population of Da Yang Shu,which has high genetic polymorphism,indicating its special genetic background,which can be used as the key object of germplasm resource investigation in the next step.(2)The UPLC-TQ-MS/MS method had determined the six compounds of Obacunnone,Fraxinellone,limonin,Dictamnine,γ-Fagarine,and Skimmianine.The content of the compounds in different producing areas is significantly different,and the content of limonin is higher than that of furoquinoline alkaloids content.Due to the content of furanquinoline alkaloids,the content of Obacunnone and Fraxinellone specified in the Chinese Pharmacopoeia of almost all production areas exceeds the standard.The similarity of chemical fingerprints ranged from0.910 to 1.000.The 27 producing areas were divided into two chemical types,and the principal component analysis of the compounds was also divided into two chemical types,which were similar to the results of fingerprint and hierarchical clustering.The results provided a reliable basis for the chemical evaluation of Dasycarpus;Most of the compounds had little correlation with climatic factors,and longitude had a greater effect on the content of Dictamnine.Genotype and metabolic pathway might be the main factors affecting the compounds.(3)Antioxidant activity studies have revealed that alkaloids and limonin compounds have a certain correlation with antioxidant capacity.ABTS free radical scavenging experiments revealed that Dictamnine content is significantly positively correlated with the antioxidant capacity of Dasycarpus root bark extracts.(4)Although the results of molecular marker clustering and fingerprint clustering are not completely consistent,they both cluster Mo Guai and Mu Yuan into one category.These two populations have relatively close geographic distances and low genetic diversity.Field investigation showed that the two populations grew in similar environments,and the germplasm resources were artificially overmined.Therefore,it is urgent to establish a wild Dasycarpus reserve for key protection.Huo Lin Guo Le and Wu La Gai with the highest content of Obacunnone and Fraxinellone were clustered into one subcluster,and the two populations had high DPPH radical scavenging ability,so they can be used as a high-quality provenance for variety breeding.Through the systematic study of genetic diversity,chemical diversity and biological activity of Dasycarpus,it provides a theoretical basis for resource conservation and germplasm breeding of Dasycarpus.