Study On Genetic Diversity Of Coptis Deltoidea

Coptis deltoidea C.Y. Cheng et Hsiao belongs to Ranunculaceae Coptis distributed mainly in Hongya and Emei in Sichuan province. It has a great medical value in tradition Chinese medicine. Several reasons such as the harsh living conditions, a special breeding system, coupled with a large number of long-term excavations, human destruction of their habitat and minimal cultivation lead to its extremely endangered and a protection in urgent need. This issue using morphological markers and RAPD markers study 16 populations of the Coptis genetic diversity, in order to reveal the genetic diversity and genetic structure, to acknowledge the genetic variation within species and to provide a theoretical basis to protect the Coptis reasonable and effective. The main results obtained are as follows:1. There is a big difference in phenotypic traits between different samples and also a variety of phenotypic traits among the different samples show different degrees of diversity by analyzing 5 phenotypic traits of 24 Coptis samples. Coefficient of variation of all traits are higher than 10%, indicating that the samples have a relatively large difference respectively, in which the number of stolon shows the largest coefficient of variation, that is 67.20%. The smallest of the coefficient of variation is height with the percentage of 12.69. Coefficient of variation is in the order of:stolon number> the length of the rhizome> buds number> the length of the primary leaf> height, revealing that the number of stolon has a greater variability than the other characters, as well as the height variation is relatively more stable than other traits. Meanwhile, from the regional level, it is found that 5 morphological traits of all the Coptis samples from Qiliping, except that the variation coefficient of plant height (12.86%) is slightly lower than the height of the Heishan village on the coefficient of variation (13.22%), the remaining 4 traits are higher than the CV variation coefficient of the Heishan village character. Accordingly the preliminary estimate, compared with the Heishan village, the Coptis samples in Qiliping reflect a larger difference on the phenotypic characteristic, and the variety of phenotypic traits among the different samples shows a higher degree of diversity. Correlation analysis indicates that plant height and the length of the primary leaf is significantly positively related, and stolon number is significantly positively correlated with buds number while the elevation shows significantly negatively correlated with buds number.2. A total of 188 loci,149 polymorphic loci, and polymorphism percentage of 79.26% has been detected by analyzing 38 Coptis samples of 16 populations using 20 primers with RAPD analysis, indicating that in the Coptis has a wealth of genetic diversity on species level. Accordingly, the genetic variation among populations index (Gst) is 0.6971. It is clear that there are 69.71 percent of the Coptis genetic variations among populations, and only 30.29% of the genetic variation exists within populations. Analysis of population genetic differentiation shows that the genetic differentiations of the Coptis mainly exist in populations between each other while only a small part of the genetic differentiation within populations. All parameters of the genetic diversity of 16 Coptis samples in Qiliping are large than the 8 populations' parameters on the genetic diversity. As we can be seen from this, the Coptis from Qiliping reveals a higher level than the Heishan village on the genetic diversity.Estimates based on Nei's unbiased genetic identity of the cluster analysis shows that the majority of populations between genetic distance and geographic distance have some relevance.3. The main reason leads to the endangerment of Coptis is due to human interference rather than its own loss of genetic diversity. In order to effectively protect the endangered medicinal plants Coptis, we strongly suggest that we should strengthen publicity and education in the frequent human activities region, and prevent the excavation and damage acts of their habitat, as the same time, we should implementation the Coptis conservation in and out of the spot.