Genetic Diversity of Wild Conyza Blinii H.lév. Based on Rapd and Srap Markers

The genetic diversity and genetic relationships among 16 populations of Conyza blinii in the Panxi area of China were assessed by RAPD and SRAP markers. Relative to independent molecular markers, the combined RAPD-SRAP data showed a more reasonable cluster (r = 0.80718), and the clustering results divided the 16 populations into three groups. One major group was formed by populations from Pzhihua city (nos. 1 to 7) and another two populations from Liangshan prefecture (nos. 8 and 9); two populations (nos. 10 and 11) collected from Liangshan clustered into the second category, and the remaining populations made up cluster III. The samples clustered into two groups based on the content of blinin (the characteristic compound of this plant), except samples 4, 5 and 16, other samples were clustered similar like molecular markers, they all gathered together based on their similar distance. The Jaccard’s similarity coefficients ranged from 0.5073 to 0.8422, the results suggested that the genetic variation of wild populations was not abundant. However, based on blinin content (detected by HPLC), there was a large difference among populations although populations had a close genetic relationship which revealed that samples were not fully related to their geographical location. The result has important implications for C. blinii characterization, improvement, and conservation. Introduction Conyza blinii H. Lév. is a traditional Chinese medicinal plant. The wild type has only been reported in the Southwest China. The two years old Conyza blinii H. Lév. (family Compositae) is distributed mainly in the Yunnan and Sichuan provinces of China. It is most abundant in the Panxi area of Sichuan with its arid, hot weather, high altitude and abundant sunlight, an environment that is best suited to C. blinii growth (Committee 2010). The Panxi area, located in southwestern Sichuan, is part of the upper Yangtze River region, which comprises Panzhihua city and Liangshan prefecture. It consists of 67,549 km of land area, and forms a unique light and heat climatic zone due to the influence of the north-south flow of the wind and its unique topography. The Panxi area has become famous for the production of C. blinii, with annual herb sales accounting for a sizeable portion of the economy in Sichuan province (Xu et al. 2004). This herb was developed as a folk medicine in the 1970s because of its excellent curative effect on chronic bronchitis (Committee 2010). Some reports have also indicated that C. blinii extract can be used to treat gastric ulcers (Su et al. 2007) due to its unique chemical composition of blinin (Yang et al. 1989). In recent years, Chinese researchers have been studying on cultivation management of C. blinii to elucidate its chemical constituents. Unfortunately work on its identification and evaluation at the molecular level is meagre. Genetic diversity of this species have been undertaken using different molecular markers. However, use of a single marker technique to study genetic diversity may lead to erroneous and Author for correspondence: . Department of Biology and Science, Sichuan Agricultural University, 625014,Ya’an, China.