Molecular data provide strong evidence of natural hybridization between native and introduced lineages of Phragmites australis in North America
- 431 Downloads
Hybridization, both within and between taxa, can be an important evolutionary stimulus for bioinvasions. Novel intra-taxon hybridizations may arise either between formerly allopatric introduced lineages, or between native and introduced lineages. The latter can occur following a cryptic invasion of a non-native lineage, such as the nineteenth century introduction to North America of a European lineage of the common reed Phragmites australis. Previous studies found no evidence of natural hybridization between native and introduced lineages of P. australis, but produced some F1 hybrids under experimental conditions when the seed parent was native and the pollen parent was introduced. In this study we used microsatellite data to compare genotypes of P. australis along a transect of approximately 2,000 km in eastern North America. Although hybridization appears uncommon, simulations and principle component analysis of genetic data provided strong evidence for natural hybridization at two sites adjacent to Lake Erie in which native and introduced lineages were sympatric. The seed parent was the native lineage in some cases, and the introduced lineage in other cases. There is now the potential for P. australis hybrids to become increasingly invasive, and managers should consider as a priority the removal of introduced stands from sites where they co-exist with native stands.
KeywordsHybridization Phragmites australis Microsatellites Invasive species Chloroplast haplotypes
Field expertise and permits were provided by Tammy Dobbie and Leonardo Cabrera Garcia from Point Pelee National Park of Canada; Rachel Carson Wildlife Refuge; Rondeau Bay Provincial Park; Paul Ashley, Canadian Wildlife Service, Big Creek National Wildlife Area. Financial support for this project was provided by NSERC and Trent University. Two anonymous reviewers provided valuable comments on this manuscript.
- Dray S, Dufour AB (2007) The ade4 package: implementing the duality diagram for ecologists. J Stat Softw 22:1–20Google Scholar
- Engloner AI (2009) Structure, growth dynamics and biomass of reed (Phragmites australis)—a review. Flora 204:331–346Google Scholar
- Freeland JR (2005) Molecular ecology. Wiley, ChichesterGoogle Scholar
- Mal TK, Narine L (2004) The biology of Canadian weeds. 129. Phragmites australis (Cav.) Trin. ex Steud. Can J Plant Sci 84:365–396Google Scholar
- Meyerson LA, Viola DV, Brown RN (2009) Hybridization of invasive Phragmites australis with a native subspecies in North America. Biol Invasions (on-line)Google Scholar
- R Development Core Team (2008) R: a language and environment for statistical computing. R foundation for statistical computing, Vienna, Austria. ISBN 3-900051-07-0, URL http://www.R-project.org
- Whyte RS, Trexel-Kroll D, Klarer DM, Shields R, Francko DA (2008) The invasion and spread of Phragmites australis during a period of low water in a lake Erie coastal wetland. J Coast Res (Special issue 55):111–120Google Scholar