Multiple introductions, polyploidy and mixed reproductive strategies are linked to genetic diversity and structure in the most widespread invasive plant across Southern Ocean archipelagos

• Published in: Molecular Ecology
• Main Authors: Mairal Pisa, Mario J., García-Verdugo, Carlos
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2023
• Subjects: Biological invasions; Breeding system; Clonality; Genetic variation; Islands; Poa annua; Polyploidy; Population genetics; Self-fertilization; Sub-Antarctic; Antarctic; Southern Ocean; The Antarctic; Kerguelen; New Zealand; Tristan; Gough; Antarc*; Australian Antarctic Program; Institut Polaire Français; Macquarie Island; Prince Edward Islands; South African National Antarctic Programme; Swiss Polar Institute
• Online Access: https://hdl.handle.net/10481/85111; https://doi.org/10.1111/mec.16809

This work received support from the Swiss Polar Institute and Ferring Pharmaceuticals through the Antarctic Circumnavigation Expedition (“ACE”). Additional fi- nancial and logistical support was provided by the South African National Research Foundation (NRF) and by the South African National Antarctic Programme (SANAP). MM and CH were also supported by the National Research Foundation (grant 89967). We thank Tasmanian Parks and Wildlife Service for granting ac- cess and collection permits for Macquarie Island and the Australian Antarctic Program for logistical support. We thank Institut polaire français Paul- Émile Victor for logistical support for sampling on Iles Kerguelen and Ile de la Possession. We thank wintering staff for sam- ple collection on Ile de la Possession. We thank the Department of Conservation for granting access and collection permits for the New Zealand islands. We thank Heritage Expeditions for providing logis- tics and voyage support. Collections were undertaken on the ACE expedition under permits granted to the expedition and its research- ers. Collections at the Prince Edward Islands, and at the Tristan da Cunha and Gough islands were permitted through the South African National Antarctic Program, notably via the Prince Edward Islands Management Committee for the former and the Tristan da Cunha Conservation Department for the latter. Biological invasions in remote areas that experience low human activity provide unique opportunities to elucidate processes responsible for invasion success. Here we study the most widespread invasive plant species across the isolated islands of the Southern Ocean, the annual bluegrass, Poa annua. To analyse geographical variation in genome size, genetic diversity and reproductive strategies, we sampled all major sub-Antarctic archipelagos in this region and generated microsatellite data for 470 individual plants representing 31 populations. We also estimated genome sizes for a subset of individuals using flow cytometry. Occasional events of island ...