Current patterns, habitat discontinuities and population genetic structure:: the case of the kelp Laminaria digitata in the English Channel
Current patterns, habitat discontinuities and population genetic structure:: the case of the kelp Laminaria digitata in the English Channel
复制标题
DOI：
10.3354/meps253111
复制
发表时间：
2003-01-01
影响因子：
2.5
通讯作者：
Valero, M
中科院分区：
文献类型：
--
作者：
Billot, C;Engel, CR;Valero, M
指状海带（Laminaria digitata）是英吉利海峡和法国大西洋海岸密集连续海带的主要物种，在那里收获高质量的藻酸盐。然而，尽管它的生态和经济的重要性，我们的知识水平和组织的遗传多样性在这个物种是缺乏的。本研究采用综合分层抽样方法，利用7个微卫星位点，探讨了扩散策略、流态和生境不连续性在形成红腹锦鸡儿遗传结构中的作用。毛地黄种群我们的研究结果表明，连续的，非破碎化的森林L。毛地黄的遗传分化距离大于10公里，尽管没有明确的人口界限。此外，隔离距离的模式表明，基因流发生优先相邻种群之间的踏脚石模型。此外，我们分析了迁移的方向，使用分配测试，并发现电流似乎在定向基因流中发挥了次要作用，除了在圣马洛湾环流。与此相反，栖息地的不连续性被发现加剧遗传分化，并导致减少孤立的立场的遗传变异。在潜在的过度开发的背景下，在布列塔尼的海带立场，这项研究表明，邻近人群的存在可能是至关重要的，以保持高水平的基因流，因此，在这个物种的遗传多样性。
Laminaria digitata is the dominant species of the dense, continuous kelp stands in the English Channel and on the Atlantic coasts of France, where it is harvested for its high quality alginates. However, in spite of its ecological and economic importance, our knowledge of the level and organisation of genetic diversity in this species is scant. Here, using comprehensive hierarchical sampling and 7 microsatellite loci, we explored the roles of dispersal strategies, current regimes and habitat discontinuities in shaping genetic structure of L. digitata populations. Our results show that continuous, non-fragmented forests of L. digitata were genetically differentiated at distances greater than 10 km, despite the absence of clear population boundaries. Furthermore, a pattern of isolation-by-distance indicated that gene flow occurred preferentially among adjacent populations following a stepping-stone model. In addition, we analysed the direction of migration using assignment tests and found that currents appeared to play a minor role in orienting gene flow, except in the Gulf of Saint Malo gyre. In contrast, habitat discontinuities were found to accentuate genetic differentiation and resulted in reduced genetic variation of isolated stands. In the context of a potential over-exploitation of kelp stands in Brittany, this study suggests that the existence of neighbouring populations can be vital to maintaining high levels of gene flow and thus, genetic diversity in this species.