云南特有濒危植物馨香木兰的遗传多样性研究

Study on Genetic Diversity of Endangered and Endemic Plant of Magnolia odoratissima( Magnoliaceae) in Yunnan Province

为研究云南特有濒危植物馨香木兰的遗传多样性水平,采用随机扩增多态DNA技术(RAPD),对云南省馨香木兰4个居群,即文山州广南县、西畴县新街、西畴县亚坪等3个天然居群及昆明树木园1个人工居群,进行遗传多样性分析。随机筛选出重复性好的8条随机引物,对70个样品的基因组DNA进行扩增,建立RAPD分析图谱。扩增结果为,共检测出84个多态位点。遗传多态位点百分率为61.90%(文山广南)、76.19%(西畴新街)、71.43%(昆明树木园)和66.67%(西畴亚坪)。遗传多样性Shannon指数为0.568 6,其中30.55%来自种群间,69.45%来自种群内;Nei’s指数为0.390 3,种群间的遗传分化系数(GST)为0.221 6。文山广南和西畴亚坪之间的遗传距离最大,昆明树木园与西畴亚坪之间的遗传距离最小。结果显示,与木兰科等其他濒危植物相比较,馨香木兰遗传多样性相对较高。根据各种群遗传背景研究结果,提出了该物种迁地保护种群遗传资源管理建议。

In order to study the genetic diversity of the endemic and endangered plant of Magnolia odoratissima in Yunnan Province, we collected 4 populations including one artificial population from Kunming Tree ’ s Garden （KM）, and three wild populations from Guangnan （G）, Xinjie （XCD） and Yapin （XPB） of Wenshan Prefec-ture .Eight RAPD primers were selected to screen 70 samples of M.odoratissima Among 84 detected sites, rpolymor-phic percentage of the four populations were 61.90 % （G）, 76.19 % （XCD）, 71.43 % （KM） and 66.67 %（ XPB） respectively.Species diversity indicated by Shannon index was 0.568 6, among which 30.55%was from the inter-populations and 69.45 % was from the inner-populations.The species diversity indicated by Nei index was 0.390 3 and the coefficient of gene differentiation among the populations was 0.221 6.Genetic distance be-tween Guangnan and Yapin was the longest, while the one between Kunming Tree’ s Garden and Yapin was the shortest.The results showed that M.odoratissima had higher genetic diversity than other endangered and endemic plants of magnoliaceae.Based on the research, relevant management suggestion on ex-situ conservation of M.odoratissima genetic resources was proposed.