Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2010
Publication Date: 10/25/2010
Publication URL: http://hdl.handle.net/10113/47585
Citation: Bodo Slotta, T.A., Foley, M.E., Chao, S., Hufbauer, R., Horvath, D.P. 2010. Assessing genetic diversity of Canada thistle (Cirsium arvense) in North America with microsatellites. Weed Science. 58:387-394. Interpretive Summary: Canada thistle is an invasive weed. This paper defines/identifies the level of genetic diversity in nearly 100 different Canada thistle populations from 22 different states and one Canadian province. The study found that there is significant movement of Canada thistle genotypes and considerable genetic diversity both within and between populations. The study also found that most populations spread by sexual reproduction rather than by vegetative reproduction. Both of these facts will impact effectiveness of various strategies to control this invasive weed. There is less genetic diversity in N. American populations than there are in populations from England suggesting that the English population was established well before the N. American population.
Technical Abstract: Canada thistle (Cirsium arvense (L.) Scop.) is a noxious weed worldwide with established populations throughout northern temperate North America. We examined genetic diversity among more than 2000 individuals representing nearly 100 North American populations of C. arvense using 7 different microsatellite markers. Results suggest asexual reproduction does not have as great an influence on dispersal or establishment. Analyses identified numerous instances where individuals from geographically distant regions clustered together indicating long distance translocation of seeds. The recurrent distribution of seed throughout North America has lead to a highly diverse gene pool. Future technologies developed for control of C. arvense should consider this diversity.