Studies On RAPD Identification And Genetic Relationship Of Medicinal Plants Of Coptis Genus

Coptis chinensis Franch. from genus of Ranunculaceae family, is one of the most important Chinese Traditional Medicines. Cultivated species and wild species such as C.deltoidea C.Y.Cheng et Hsiao, C.teetoides C.Y.Cheng, C.omeiensis (Chen) C.Y.Cheng, C.teeta Wall. and C.linearisepala T.Z.Wang et C.k.hsieh have been used for treament. In addition, Coptis japonica Makino. has been included in Pharmacopoeia Japonica officially.By means of RAPD technique, the thesis aims to. 1) study the genetic characters and the interspecific relationship of medicinal plants of Coptis genus, establish a new method for their identification and provide evidence for their classification at a level of molecular biology. 2) investigate the genetic diversity and provide molecular evidence for the genuineness of Chuanhuanglian. 3) discuss the relation between genetic characters and contents of alkaloids of plants of medicinal Coptis genus.The optimal reaction system of RAPD-PCR has been obtained with aid of central composite design (CCD). The interaction of 5 essential factors (Mg~2+, dNTP, TaqDNA Polymerase, random primer and template DNA) has beenobserved in the experiment. The result suggests that reaction system optimized with good stability and high reproducibility is suitable for RAPD of medicinal plants of Coptis.The fingerprints of medicinal plants of Coptis. has been established with RAPD technique, NETS genetic distances and character differences have been carried out and a UPGMA dendrogram has been constructed, the results show as follows:1) there are abundant genetic polymorphisms among 7 species in Coptis genus, the method of RAPD can be used to identify the plants of Coptis.2) C.teeta has a closer genetic relationship with C.teetoides, C.linearisepala has a close one with C.chinensis, but C.japonica present further genetic relationship with others species.3) species which have close genetic relationship have similar contents of berberine, Jatrorrhizine and Palmatine.Sichuan province is a genuine producing area. The genomic DNAs collected from Hongya, Pengzhou and Shizhu(Chongqing) were analyzed by RAPD. The results indicate that the genetic diversities of different geographic populations are not far different from that in single population. As a genuine Chinese Traditional Medicine, Chuanhuanglian has a steady genetic character. Chuanhuanglian from 3 different collection areas have similar contents of berberine, Jatrorrhizine and Palmatine.With the application of RAPD technique the thesis identifythe medicinal plants of Coptis genus, discuss the genetic relationship among species, assess the genuineness of Chuanhuanglian and provide scientific evidence for classification and further study at morphologic, chemical and molecular biological level.