ABSTRACT
The genus Tripterygium is an immune suppressor in the Chinese traditional medicines. Due to the habitat destruction and anthropogenic over-exploitation, the wild genus Tripterygium plants have decreased dramatically in recent years or even been endangered. It is critical to evaluate and protect genus Tripterygium wild resource. In this research, simple sequence repeat (SSR) molecular markers were applied to the investigation of the genetic diversity and genetic structure of 28 populations for genus Tripterygium (396 samples from 9 provinces in China). We found a high level of genetic diversity (percentage of polymorphic loci PPL=77.29%, Shannon's information index I=0.639 4; Nei's expected heterozygosity H=0.359 9) and high genetic differentiation among the populations (gene flow Nm=0.228 7). Based on Nei's genetic distance, the phylogenic tree of populations was constructed and 28 populations were divided into 6 clusters according to STRUCTURE clustering analysis. T. hypoglaucumwas was mainly divided into 3 clusters, including Sichuan, Yunnan and GuizhouChongqing. T. regelii was separated to cluster 4, while T. wilfordii was divided into two clusters:the transition type LQ and NY were divided into cluster 5, and the others were in cluster 6. These results provide a theory basis for the conservation of wild resource, research of genetic polymorphism and molecular marker for assisted breeding of genus Tripterygium.
ABSTRACT
In order to figure out the status and distribution of the wild and cultivated resources of traditional Chinese medicine Daphnes Cortex, its suitable habitat and endangering factors were analyzed to provide the basis for its rational use, protection and cultivation.Our research group tooka resources survey in Shanxi, Gansu, Sichuan and Qinghai provinces, which include 23 counties. Investigation and sampling investigation combined with interview were carried out. The total reserve of resources was estimated through route-quadrat method in combination with the vegetation and soil-type map area method. The results indicated that there was no obvious change between the present distribution ranges of the wild Daphnes Cortex and its historical records, but the density of the population has undergone major changes. The wild reserves resources has declined seriously, even on the verge of exhaustion in some regions. According to the survey results, the current total reserve of the wild Daphnes Cortex in the four provinces was no more than 600 tons. Simultaneously, we only found the cultivated resource in a mountain at an altitude of about 2 800 m in Kang county of Gansu province, which cropping scope was about 33 000 m². The cultivated resource can't provide medicinal products at present, because their growing period is too short to have curative effect. Destructive excavation and the longer growth cycle result in a sharp decline of the wild resources reserves, even to the point of extinction. Artificial cultivation of product will become the main source of medicinal resources in the future. Therefore, we must protect its suitable habitat, formulate rational harvesting policy, strengthen the supervision of government departments, collect and establish the germplasm nursery and seed bank. On the basis, we must carry out studies into seed-selecting and breeding as well as rapid propagation and growth technology at once.