Department of Ecology and Evolutionary Biology, University of Michigan, 1105 North University, 2020E Biological Science Building, Ann Arbor, MI, 48109-1085, USA.
Department of Plant Biology, University of Georgia, Rm 3613; 2502 Miller Plant Sciences, Athens, GA, 30602-7271, USA.
Heredity (Edinb). 2019 Jan;122(1):29-40. doi: 10.1038/s41437-018-0106-x. Epub 2018 Jul 2.
Examining how the landscape may influence gene flow is at the forefront of understanding population differentiation and adaptation. Such understanding is crucial in light of ongoing environmental changes and the elevated risk of ecosystems alteration. In particular, knowledge of how humans may influence population structure is imperative to allow for informed decisions in management and conservation as well as to gain a better understanding of anthropogenic impacts on the interplay between gene flow, genetic drift, and selection. Here, we use genome-wide molecular markers to characterize the population genetic structure and connectivity of Ipomoea purpurea (Convolvulaceae), a noxious invasive weed. We, likewise, assess the interaction between natural and human-driven influences on genetic differentiation among populations. Our analyses find that human population density is an important predictor of pairwise population differentiation, suggesting that the agricultural and/or horticultural trade may be involved in maintaining some level of connectivity across distant agricultural fields. Climatic variation appears as an additional predictor of genetic connectivity in this species. We discuss the implications of these results and highlight future research needed to disentangle the mechanistic processes underlying population connectivity of weeds.
研究景观如何影响基因流是理解种群分化和适应的前沿领域。考虑到正在发生的环境变化和生态系统改变的风险增加，这种理解至关重要。特别是，了解人类如何影响种群结构对于在管理和保护中做出明智决策以及更好地了解人类活动对基因流、遗传漂变和选择之间相互作用的影响是必要的。在这里，我们使用全基因组分子标记来描述Ipomoea purpurea（旋花科）的种群遗传结构和连通性，Ipomoea purpurea 是一种有害的入侵杂草。我们同样评估了自然和人为因素对种群间遗传分化的相互作用。我们的分析发现，人口密度是种群间分化的重要预测因子，这表明农业和/或园艺贸易可能参与维持远距离农业领域的某种连通性。在该物种中，气候变异似乎也是遗传连通性的另一个预测因子。我们讨论了这些结果的意义，并强调了需要进一步研究来理清杂草种群连通性的潜在机制过程。
