Androsiuk Piotr, Koc Justyna, Chwedorzewska Katarzyna Joanna, Górecki Ryszard, Giełwanowska Irena
Department of Plant Physiology, Genetics and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland.
Department of Agronomy, Warsaw University of Life Sciences-SGGW, Warszawa, Poland.
PeerJ. 2019 May 15;7:e6888. doi: 10.7717/peerj.6888. eCollection 2019.
L. is an example of a plant characterized by abundant, worldwide distribution from polar to equatorial regions. Due to its high plasticity and extraordinary expansiveness, is considered an invasive species capable of occupying and surviving in a wide range of habitats including pioneer zones, areas intensively transformed by human activities, remote subarctic meadows and even the Antarctic Peninsula region.
In the present study, we evaluated the utility of inter-primer binding site (iPBS) markers for assessing the genetic variation of populations representing contrasting environments from the worldwide range of this species. The electrophoretic patterns of polymerase chain reaction products obtained for each individual were used to estimate the genetic diversity and differentiation between populations.
iPBS genotyping revealed a pattern of genetic variation differentiating the six studied populations characterized by their different climatic conditions. According to the analysis of molecular variance, the greatest genetic variation was recorded among populations, whereas 41.75% was observed between individuals within populations. The results of principal coordinates analysis (PCoA) and model-based clustering analysis showed a clear subdivision of analyzed populations. According to PCoA, populations from Siberia and the Kola Peninsula were the most different from each other and showed the lowest genetic variability. The application of STRUCTURE software confirmed the unique character of the population from the Kola Peninsula.
The lowest variability of the Siberia population suggested that it was subjected to genetic drift. However, although demographic expansion was indicated by negative values of Fu's statistic and analysis of mismatch distribution, it was not followed by significant traces of a bottleneck or a founder effect. For the Antarctic population, the observed level of genetic variation was surprisingly high, despite the observed significant traces of bottleneck/founder effect following demographic expansion, and was similar to that observed in populations from Poland and the Balkans. For the Antarctic population, the multiple introduction events from different sources are considered to be responsible for such an observation. Moreover, the results of STRUCTURE and PCoA showed that the from Antarctica has the highest genetic similarity to populations from Europe.
The observed polymorphism should be considered as a consequence of the joint influence of external abiotic stress and the selection process. Environmental changes, due to their ability to induce transposon activation, lead to the acceleration of evolutionary processes through the production of genetic variability.
L. 是一种植物，其特点是在全球范围内分布广泛，从极地到赤道地区均有生长。由于其高度的可塑性和非凡的扩张性，它被视为一种入侵物种，能够在包括先锋区、人类活动强烈改造的地区、偏远的亚北极草甸甚至南极半岛地区等广泛的栖息地中占据并生存。
在本研究中，我们评估了引物结合位点间（iPBS）标记在评估代表该物种全球范围内不同环境的种群遗传变异方面的效用。对每个个体获得的聚合酶链反应产物的电泳图谱用于估计种群间的遗传多样性和分化。
iPBS基因分型揭示了一种遗传变异模式，该模式区分了六个以不同气候条件为特征的研究种群。根据分子方差分析，最大的遗传变异记录在种群之间，而种群内个体之间观察到41.75%的变异。主坐标分析（PCoA）和基于模型的聚类分析结果显示分析的种群有明显的细分。根据PCoA，来自西伯利亚和科拉半岛的种群彼此差异最大，且遗传变异性最低。STRUCTURE软件的应用证实了科拉半岛种群的独特特征。
西伯利亚种群的最低变异性表明它受到了遗传漂变的影响。然而，尽管Fu氏统计量的负值和错配分布分析表明存在种群扩张，但并未随之出现明显的瓶颈效应或奠基者效应痕迹。对于南极种群，尽管在种群扩张后观察到明显的瓶颈/奠基者效应痕迹，但观察到的遗传变异水平却出奇地高，且与在波兰和巴尔干半岛种群中观察到的水平相似。对于南极种群，来自不同来源的多次引入事件被认为是造成这种观察结果的原因。此外，STRUCTURE和PCoA的结果表明，来自南极洲的该物种与欧洲种群具有最高的遗传相似性。
观察到的多态性应被视为外部非生物胁迫和选择过程共同影响的结果。环境变化由于其诱导转座子激活的能力，通过产生遗传变异性导致进化过程加速。
