Studies On Identification Of Original Plant Of Traditional Chinese Medicine From Their Adultrents Using ITS2Sequence

Traditional Chinese medicine market has always some difficulties in discriminating thegenuine Chinese medicinal material and their fakement, which not only prevents the rapiddevelopment of traditional Chinese medicine, but also threatens the safety of people’s life.Nowadays DNA barcoding bring hopes for the authentication of traditional Chinese medicine.This method is quick, accurate and of unique repeatability. In the former candidate barcodescreening discussion, the ITS2locus is emphasized because of its small length, easilyamplified both ends and successful identifiability. As a result this paper discuss theidentifiability of the ITS2sequence in17Chinese medicines, and select2medicines——Ligustri Lucidi Fructus and Radix et Rhizoma Rhei,as a representative respectively of uniquesoure and multi-source, to do some more research. Based on the experiment results, theconclusions are as follow:1. The minimum inter-specific K2P distance (3.2%) was obviously higher than themaximal intra-specific one (0.90%). The different samples of Ligustrum lucidum wereclustered in a clade. The molecular morphology of secondary structures of ITS2was distinctbetween Ligustrum lucidum and its adulterants.ITS2can be applied in discrimination of theoriginal plant of Ligustri Lucidi Fructus and its adulterants.2. The K2P distance of the minimum inter-specific38.6%was higher than that of themaximum intra-specific8.0%. The different samples of three original plants of Radix etRhizoma Rhei were clustered into one clade. We conclude that the ITS2fragment could beused as a candidate barcode for identifying original plants of Radix et Rhizoma Rhei from itsadulterants Rhizoma et Radix Polygoni Cuspidati and Radix Rumicis Obtusifolii.3.NJ dendrograms based on K2P model of ITS2sequences review that the differentsamples of original plants of Ginseng Radix et Rhizoma,Anisi Stellati, Notoginseng Radix etRhizoma,Kaempferiae Rhizoma,Chuanxiong Rhizoma,Pogostemonis Herba,SalvaeMiltiorrhizae Radix et Rhizoma,Bletillae Rhizoma,Kochiae Fructus,Panacis JaponiciRhizoma,Galangae Fructus, Rhodiolae Crenulatae Radix et Rhizoma and Entadae Semen were separately clustered into one clade. We conclude that the ITS2fragment could be used asa candidate barcode for identifying the above-mentioned13Chinese Herbal Medicine andBelamcandae Rhizoma can be discriminated by inter-specific sequence alignment. ClematidisArmandii Caulis can be identified from it’s adulterants by BLAST, DNA barcoding and theITS2sequence has a wide prospect in authenticating Traditional Chinese Medicine.