A tree well travelled: global genetic structure of the invasive tree Acacia saligna. (21st November 2014)

• Record Type: Journal Article
• Authors: Thompson, Genevieve D.; Bellstedt, Dirk U.; Richardson, David M.; Wilson, John R. U.; Le Roux, Johannes J.; Richardson, James
• Is Part Of: Journal of biogeography. Volume 42:Number 2(2015:Feb.)
• Page Start: 305
• Page End: 314
• Publication Date: 2014-11-21
• Subjects: Biogeography -- Periodicals; 578.09
• DOI: 10.1111/jbi.12436
• Languages: English
• ISSNs: 0305-0270

Abstract

<abstract abstract-type="main" id="jbi12436-abs-0001"> <title>Abstract</title> <sec id="jbi12436-sec-0001" sec-type="section"> <title>Aim</title> <p>Invasiveness of an introduced species in one region is often used to predict risk and inform management of the same species elsewhere. This assumes that entities in both regions are equivalent in their ecology and response to management. However, intraspecific genetic variation can result in differences in performance between regions. We conducted population genetic and phylogeographic analyses of the widely introduced and intraspecifically diverse Australian tree species <italic>Acacia saligna, </italic> in order to improve our understanding of its worldwide invasion history.</p> </sec> <sec id="jbi12436-sec-0002" sec-type="section"> <title>Location</title> <p>The native range of <italic>A. saligna</italic> in Western Australia and introduced ranges in eastern Australia, Israel, Italy, New Zealand, Portugal, South Africa, Spain and the USA.</p> </sec> <sec id="jbi12436-sec-0003" sec-type="section"> <title>Methods</title> <p>We analysed microsatellite genotype data obtained from 447 individuals of <italic>A. saligna</italic> (including reference populations of known subspecies lineages) using Bayesian assignment analysis. We also reconstructed parsimony networks and a phylogeny using data from the nuclear external transcribed spacer (ETS) gene region for a subset of 120 individuals.</p> </sec> <sec id="jbi12436-sec-0004" sec-type="section"> <title>Results</title> <p>There was no consistent genetic pattern in introduced populations in different parts of the world. All three subspecies lineages of <italic>A. saligna</italic> have been moved around the world, showing high levels of admixture in some introduced populations. A previously identified novel and cultivated South African lineage was also identified in Portugal and Italy.</p> </sec> <sec id="jbi12436-sec-0005" sec-type="section"> <title>Main conclusions</title> <p>With different subspecies lineages present in different regions globally, it is unclear exactly how effective management approaches of invasions in one region will be in other regions. For example, the successful biological control agents against cultivated lineages of <italic>A. saligna</italic> in South Africa will probably be effective against similar genotypes in Portugal but not against dissimilar lineages present elsewhere. Further work is needed to conclusively link the relative extent of invasions to genetic differences, and to determine whether genetic novelty can explain the widespread invasions of <italic>A. saligna</italic> observed in South Africa and Portugal.</p> </sec> </abstract>