中文摘要：

利用ISSR分子标记技术，分析粗毛牛膝菊（Galinsoga quadriradiata）在中国分布的18个地理种群遗传多样性和遗传结构特点，为粗毛牛膝菊的防控奠定基础。结果表明：筛选的10条引物共扩增出349个位点，经Popgene软件分析，粗毛牛膝菊种群多态位点百分比（P）为8．88％～29．51％，Nei基因多样性指数（H）为0．0248—0．1023；种群遗传分化系数（Gst）为0．4663，种群间基因流（Nm）为0．5723；遗传相似度平均为0．9404，遗传距离平均为0.0621，UPGMA聚类分析将18个粗毛牛膝菊地理种群分为5大类；经Mantel检验，不同地理种群遗传距离与地理距离相关性不显著。研究表明，粗毛牛膝菊种群的遗传多样性较低；各地理种群间产生了一定程度的遗传分化；粗毛牛膝菊的入侵及扩散途径以人为多次反复传播为主。

英文摘要：

The genetic diversity and genetic structure of 18 Galinsoga quadriradiata populations in China were analyzed by inter-simple sequence repeat （ISSR）, to lay a foundation for its con- trol. The results showed that 10 primer groups were screened and 349 loci were gotten by ISSR marker analysis. Analyzed by Popgene software, the percentage of polymorphic loci （P） was 8.88%-29.51%, the Nei＇s gene diversity index （H） among populations was 0.0248-0.1023, coefficient of gene differentiation （ G,t ） among populations was 0.4663, gene flow （ Nm ） among populations was 0.5723, genetic similarity among populations was 0.9404 and genetic distance among populations was 0.0621. The 18 G. quadriradiata populations were clustered into 5 groups by UPGMA cluster analysis. The Mantel test suggested that there was no significant correlation between the genetic distance and geographic distance of different G. quadriradiata populations. In summary, our results suggested that there existed a lower level of genetic diversity and higher level of genetic differentiation of G. quadriradiata populations. The spread of G. quadriradiata in the studied regions was mainly attributed to the events of human-mediated long-distance and re- peated multiple dispersal of seeds.