Böckelmann Jörg, Tremetsberger Karin, Šumberová Kateřina, Kohl Gudrun, Grausgruber Heinrich, Bernhardt Karl-Georg
Department of Integrative Biology and Biodiversity Research Institute of Botany University of Natural Resources and Life Sciences Vienna Austria.
Present address: Division of Tropical Ecology and Animal Biodiversity Department of Botany and Biodiversity Research University of Vienna Vienna Austria.
Ecol Evol. 2020 Mar 17;10(8):3620-3635. doi: 10.1002/ece3.6109. eCollection 2020 Apr.
Many ephemeral mudflat species, which rely on a soil seed bank to build up the next generation, are endangered in their natural habitat due to the widespread regulation of rivers. The aim of the present study was to elucidate the role of the soil seed bank and dispersal for the maintenance of genetic diversity in populations of near-natural river habitats and anthropogenic habitats created by traditional fish farming practices using as a model. Using microsatellite markers, we found no difference in genetic diversity levels between soil seed bank and above-ground population and only moderate differentiation between the two fractions. One possible interpretation is the difference in short-term selection during germination under specific conditions (glasshouse versus field) resulting in an ecological filtering of genotypes out of the reservoir in the soil. River populations harbored significantly more genetic diversity than populations from the anthropogenic pond types. We suggest that altered levels and patterns of dispersal together with stronger selection pressures and historical bottlenecks in anthropogenic habitats are responsible for the observed reduction in genetic diversity. Dispersal is also supposed to largely prohibit genetic structure across Europe, although there is a gradient in private allelic richness from southern Europe (high values) to northern, especially north-western, Europe (low values), which probably relates to postglacial expansion out of southern and/or eastern refugia.
许多依赖土壤种子库来繁衍下一代的短暂性泥滩物种，由于河流普遍受到调控，其在自然栖息地面临濒危。本研究的目的是，以传统养鱼方式创造的近自然河流栖息地和人为栖息地的种群为模型，阐明土壤种子库和扩散对维持遗传多样性的作用。使用微卫星标记，我们发现土壤种子库和地上种群之间的遗传多样性水平没有差异，且两部分之间只有适度分化。一种可能的解释是，在特定条件下（温室与田间）萌发期间短期选择的差异，导致对土壤中种子库基因型的生态筛选。河流种群的遗传多样性明显高于人为池塘类型的种群。我们认为，人为栖息地中扩散水平和模式的改变，以及更强的选择压力和历史瓶颈，是观察到的遗传多样性降低的原因。扩散也被认为在很大程度上阻止了欧洲各地的遗传结构形成，尽管从南欧（高值）到北欧，尤其是西北欧（低值），特有等位基因丰富度存在梯度，这可能与冰期后从南部和/或东部避难所的扩张有关。
