Microsatellite matrix of Poa annua

Comparative studies of invasive species in human-inhabited versus truly uninhabited habitats, particularly on their genetic structure, remain scarce. Sub-Antarctic islands provide an ideal system to study invasions in such contrasting environments as they represent semi-pristine conditions in highly remote areas that are accessible only through a small number of introduction routes. Here we studied the invasion genetics of annual bluegrass Poa annua on the Prince Edward Islands (PEI) that include the inhabited Marion Island and the uninhabited Prince Edward Island. We analysed variation at nuclear microsatellite loci and performed flow cytometry analyses to compare the genetic diversity and structure of this widespread invasive grass. We also used ecological niche models to estimate currently suitable habitat in these islands. We found high levels of genetic diversity and evidence for extensive admixture between genetically distinct groups of P. annua on Marion Island. In contrast, Prin...