Shi W, Yang C-F, Chen J-M, Guo Y-H
Laboratory of Plant Systematics and Evolutionary Biology, College of Life Sciences, Wuhan University, Wuhan, Hubei, China.
Plant Biol (Stuttg). 2008 Jul;10(4):485-91. doi: 10.1111/j.1438-8677.2008.00035.x.
To examine if the cultivation process has reduced the genetic variation of modern cultivars of the traditional Chinese medicinal plant, Coptis chinensis, the levels and distribution of genetic variation was investigated using ISSR markers. A total of 214 C. chinensis individuals from seven wild and three cultivated populations were included in the study. Seven ISSR primers were used and a total of 91 DNA fragments were scored. The levels of genetic diversity in cultivated populations were similar as those in wild populations (mean PPL = 65.2% versus PPL = 52.4%, mean H = 0.159 versus H = 0.153 and mean I = 0.255 versus I = 0.237), suggesting that cultivation did not seriously influence genetic variation of present-day cultivated populations. Neighbour-joining cluster analysis showed that wild populations and cultivated populations were not separated into two groups. The coefficient of genetic differentiation between a cultivar and its wild progenitor was 0.066 (G(st)), which was in good accordance with the result by amova analysis (10.9% of total genetic variation resided on the two groups), indicating that cultivated populations were not genetically differentiated from wild progenitors. For the seven wild populations, a significant genetic differentiation among populations was found using amova analysis (45.9% of total genetic variation resided among populations). A number of causes, including genetic drift and inbreeding in the small and isolated wild populations, the relative limited gene flow between wild populations (N(m) = 0.590), and high gene flow between cultivars and their wild progenitors (N(m) = 7.116), might have led to the observed genetic profiles of C. chinensis.
为了研究栽培过程是否降低了传统中药材黄连现代栽培品种的遗传变异，利用ISSR标记对遗传变异水平和分布进行了调查。该研究共纳入了来自7个野生种群和3个栽培种群的214株黄连个体。使用了7条ISSR引物，共记录了91个DNA片段。栽培种群的遗传多样性水平与野生种群相似（平均多态位点百分率PPL = 65.2% 对比PPL = 52.4%，平均香农指数H = 0.159对比H = 0.153，平均信息指数I = 0.255对比I = 0.237），这表明栽培并未严重影响当今栽培种群的遗传变异。邻接法聚类分析表明，野生种群和栽培种群并未分为两组。一个栽培品种与其野生祖先之间的遗传分化系数为0.066（Gst），这与方差分析的结果高度一致（总遗传变异的10.9%存在于两组之间），表明栽培种群与野生祖先之间没有遗传分化。对于7个野生种群，通过方差分析发现种群间存在显著的遗传分化（总遗传变异的45.9%存在于种群间）。包括小而孤立的野生种群中的遗传漂变和近亲繁殖、野生种群之间相对有限的基因流（Nm = 0.590）以及栽培品种与其野生祖先之间的高基因流（Nm = 7.116）等多种原因，可能导致了观察到的黄连遗传特征。
