Brennan Georgina, Kregting Louise, Beatty Gemma E, Cole Claudia, Elsäßer Björn, Savidge Graham, Provan Jim
School of Biological Sciences, Queen's University Belfast, , 97 Lisburn Road, Belfast BT9 7BL, UK.
J R Soc Interface. 2014 Mar 26;11(95):20140197. doi: 10.1098/rsif.2014.0197. Print 2014 Jun 6.
Gene flow in macroalgal populations can be strongly influenced by spore or gamete dispersal. This, in turn, is influenced by a convolution of the effects of current flow and specific plant reproductive strategies. Although several studies have demonstrated genetic variability in macroalgal populations over a wide range of spatial scales, the associated current data have generally been poorly resolved spatially and temporally. In this study, we used a combination of population genetic analyses and high-resolution hydrodynamic modelling to investigate potential connectivity between populations of the kelp Laminaria digitata in the Strangford Narrows, a narrow channel characterized by strong currents linking the large semi-enclosed sea lough, Strangford Lough, to the Irish Sea. Levels of genetic structuring based on six microsatellite markers were very low, indicating high levels of gene flow and a pattern of isolation-by-distance, where populations are more likely to exchange migrants with geographically proximal populations, but with occasional long-distance dispersal. This was confirmed by the particle tracking model, which showed that, while the majority of spores settle near the release site, there is potential for dispersal over several kilometres. This combined population genetic and modelling approach suggests that the complex hydrodynamic environment at the entrance to Strangford Lough can facilitate dispersal on a scale exceeding that proposed for L. digitata in particular, and the majority of macroalgae in general. The study demonstrates the potential of integrated physical-biological approaches for the prediction of ecological changes resulting from factors such as anthropogenically induced coastal zone changes.
大型海藻种群中的基因流动会受到孢子或配子扩散的强烈影响。反过来，这又受到水流影响与特定植物繁殖策略相互作用的影响。尽管有几项研究已证明大型海藻种群在广泛的空间尺度上存在遗传变异性，但相关的水流数据在空间和时间上通常解析度较差。在本研究中，我们结合了种群遗传学分析和高分辨率水动力建模，以研究斯特兰福德海峡海带（Laminaria digitata）种群之间的潜在连通性，该海峡是一条狭窄通道，其特点是有强水流将大型半封闭的斯特兰福德湖与爱尔兰海相连。基于六个微卫星标记的遗传结构水平非常低，表明基因流动水平很高，呈现出隔离距离模式，即种群更有可能与地理上相邻的种群交换迁移个体，但偶尔也会有远距离扩散。粒子追踪模型证实了这一点，该模型表明，虽然大多数孢子在释放地点附近沉降，但仍有扩散到数公里外的可能性。这种种群遗传学与建模相结合的方法表明，斯特兰福德湖入口处复杂的水动力环境能够促进扩散，其规模尤其超过了针对掌状海带以及一般大多数大型海藻所提出的扩散规模。该研究证明了综合物理 - 生物学方法在预测由人为引起的海岸带变化等因素导致的生态变化方面的潜力。
