Submitted to: Wetlands
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/31/2006
Publication Date: 12/1/2006
Citation: Gaskin, J.F., Kazmer, D.J. 2006. Comparison of ornamental and invasive saltcedar in the USA northern Great Plains using chloroplast and nuclear DNA sequence markers. Wetlands. 26(4):939-950. Interpretive Summary: We used DNA markers to determine if invasive saltcedar is originating from garden plantings. Analyses indicated that the plant invasion is originating from other invasions, not from the garden plants, but garden plants do have the potential to invade.
Technical Abstract: Saltcedars (Tamarix ramosissima, T. chinensis, and their hybrids) have invaded riverways and lakeshores across the western USA and northern Mexico. In Montana, ornamental plantings of saltcedar have been hypothesized, to varying degrees, to be the origin of nearby, wild populations. To examine this hypothesis, we compared chloroplast and nuclear DNA sequences from 36 ornamental and 182 wild saltcedars from Montana, North Dakota, and Wyoming, USA. We found that ornamental and wild population genotype frequencies were highly dissimilar. Also, genotype frequencies of hypothetical propagule populations under scenarios of random mating, self-fertilization, and clonal reproduction in the ornamental population were highly dissimilar to the genotype frequencies of the wild populations. Assignment tests indicated that the majority of wild genotypes originated from other wild plants, not from ornamental plants. However, ornamental plants could not be excluded as contributors to wild populations because all chloroplast and nuclear haplotypes found in the ornamental plants were found at some frequency in the wild. These findings suggest that while ornamental saltcedars are not the sole source of wild saltcedar, they do have potential to contribute genetic material to an invasion or re-establish a population after existing wild saltcedars are removed.