Phylogeny Analysis Of Three Medicinal Plants Based On DNA Barcoding

The three medicinal plants of agarwood,rosewood and Gouteng had many pharmacological activities and high medicinal value,but there were phenomena such as confusion,shoddyness,and indistinguishable species.After more than 10 years of development and application,DNA barcoding technology has been widely used for species classification and identification of medicinal plants,which can make up for deficiencies in traditional identification methods.In present study,the species belonging to the genus Aquilaria,Dalbergia and Uncaria are studied through five universal barcodes(ITS,matK,rbcL,psbA-trn H,and trn L-trn F).Aims to verified the feasibility of DNA barcoding in species identification and detected the phylogenetic relationships of these three medicinal plants.Concluded as follow:(1)Phylogeny analysis of Aquilaria: A total of 608 sequences included 23 species of Aquilaria and Gyrinops were analyzed using six DNA barcodes(ITS,matK,rbcL,psb A-trnH,trn L-trn F and ITS + trnL-trnF).The combination barcode ITS + trnL-trnF has more mutation sites,larger intra-/interspecific distances and higher species discrimination rates,and has better resolution within the phylogenetic tree,but it is still difficult to clearly distinguish two closely related species Aquilaria crassna and Aquilaria subintegra.(2)Phylogeny analysis of Dalbergia: DNA extraction,purification and PCR amplification of three Dalbergia odorifera samples were performed.The sequence characteristics and phylogenetic analysis were analyzed using almost all existing Dalbergia sequences.The results show that the modified CTAB method can be used for DNA extraction of Dalbergia odorifera.The combination barcode ITS + mat K + rbcL has better species identification ability and it can reflect the difference between species of Dalbergia.Therefore,the ITS + matK + rbcL sequence is a suitable barcode for identifying Dalbergia species.(3)Phylogeny analysis of Uncaria: Based on 132 ITS sequences from 12 species of Uncaria which recorded in Flora of China,the results showed that the ITS sequence has more variable sites than the ITS2 sequence.The phylogenetic relationships of most Uncaria species were detected within phylogenetic tree using ITS sequences.And the ITS2 secondary structure can be used as a candidate method for distinguishing Uncaria yunnanensis and Uncaria lanosa.