ARS | Publication request: Levels of novel hybridization in the saltcedar invasion compared over seven decades

Submitted to: Biological Invasions
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 16, 2011
Publication Date: March 1, 2012
Repository URL: http://handle.nal.usda.gov/10113/55119
Citation: Gaskin, J.F., Birken, A.S., Cooper, D.J. 2012. Levels of novel hybridization in the saltcedar invasion compared over seven decades. Biological Invasions. 14(3):693–699.

Interpretive Summary: Hybridization can help plants become invasive. We studied hybridization levels in saltcedar plants (Tamarix spp.) of varying ages that span the history of an invasion along the Green River, UT, USA. Plants ranging in establishment dates from 1930s to seedlings were analyzed genetically. All plants sampled, even those established before the Green River saltcedars were numerous, were assigned as hybrids, not as parental types that are still found in more extreme southern and northern latitudes in the USA. Our collections either did not capture the earliest parental types, or the first introductions to the Green River were already products of hybrid events. In either case, it appears that hybrids have been a dominant part of this local invasion history, from establishment through invasion spread stages.

Technical Abstract: Hybridization is proposed as one process that can enhance a plant species’ invasive ability. We quantified the levels of hybridization of 180 saltcedar plants (Tamarix spp.) of varying ages that span the history of an invasion along the Green River, UT, USA. Plants ranging in establishment dates from 1930s to seedlings were analyzed using Amplified Fragment Length Polymorphisms (AFLPs). All plants sampled, even those established before the Green River saltcedars were numerous, were assigned as hybrids, not as parental types that are still found in more extreme southern and northern latitudes in the USA. Our collections either did not capture the earliest parental types, or the first introductions to the Green River were already products of hybrid events. In either case, it appears that hybrids have been a dominant part of this local invasion history, from establishment through invasion spread stages.