How much of the invader's genetic variability can slip between our fingers? A case study of secondary dispersal of Poa annua on King George Island (Antarctica)

Abstract

We studied an invasion of Poa annua on King George Island (Maritime Antarctic). The remoteness of this location, its geographic isolation, and its limited human traffic provided an opportunity to trace the history of an invasion of the species. Poa annua was recorded for the first time at H. Arctowski Polish Antarctic Station in the austral summer of 1985/6. In 2008/9, the species was observed in a new locality at the Ecology Glacier Forefield (1.5 km from “Arctowski”). We used AFLP to analyze the genetic differences among three populations of P. annua: the two mentioned above (Station and Forefield) and the putative origin of the introduction, Warsaw (Poland). There was 38% genetic variance among the populations. Pairwise ФPT was 0.498 between the Forefield and Warsaw populations and 0.283 between Warsaw and Station. There were 15 unique bands in the Warsaw population (frequency from 6% to 100%) and one in the Station/Forefield populations (which appears in all analyzed individuals from both populations). The Δ(K) parameter indicated two groups of samples: Warsaw/Station and Forefield. As indicated by Fu's Fs statistics and an analysis of mismatch distribution, the Forefield population underwent a bottleneck and/or founder effect. The Forefield population was likely introduced by secondary dispersal from the Station population.

Seed germination and invasion success of Poa annua L. in Antarctica

“…To protect native Antarctic plant communities from the negative impact of P. annua invasion, we already started an eradication process [4]. Nevertheless, seed germination from the soil seed bank may present problems for the control of this species in years to come, especially as this population has already started to form daughter populations [7].…”

“…In the 2014/2015 Antarctic summer season, an invasive population of this species spreading in Point Thomas Oasis (King Georg Island, South Shetlands, maritime Antarctic) consisted of almost 1,500 tussocks [4]. The existence of this population at Point Thomas Oasis for over 30 years [3] together with the ability of the local population to produce viable seeds able to germinate [5] and the spreading of the species in the Oasis [7] indicate the species' invasion success in the region [4].…”

Precise evaluation of tissue culture-induced variation during optimisation of in vitro regeneration regime in barley

“…This approach was recently extended, enabling quantification of only the site DNA methylation alterations (Bednarek et al 2017). Methylation amplified fragment length polymorphism (metAFLP) enables quantitative analysis of both sequence and DNA methylation changes affecting Acc65I-KpnI restriction sites (Bednarek et al 2007;Chwedorzewska and Bednarek 2012;Machczyńska et al 2014b;Wódkiewicz et al 2018). Both methods were successfully used for the analysis of tissue culture-induced variation (Coronel et al 2018;Gimenez et al 2016;Goyali et al 2018;Mikula et al 2011).…”

What affects the probability of biological invasions in Antarctica? Using an expanded conceptual framework to anticipate the risk of alien species expansion

“…For example, the only successful alien flowering plant P. annua exhibits a high tolerance to saline, poorly aerated, and compacted soils (e.g., Chwedorzewska et al 2015;Giełwanowska et al 2011). A population of this species existing at Point Thomas Oasis for over 30 years displays specific traits that enabled its successful invasion (Wódkiewicz et al 2014(Wódkiewicz et al , 2018Galera et al 2015Galera et al , 2017. High phenotypic plasticity of this species may be a key driving factor.…”