Contrasting genetic diversity patterns in two sister kelp species co-distributed along the coast of Brittany, France

We investigated patterns of genetic structure in two sister kelp species to explore how distribution width along the shore, zonation, latitudinal distribution and historical factors contribute to contrasting patterns of genetic diversity. We implemented a hierarchical sampling scheme to compare patterns of genetic diversity and structure in these two kelp species co-distributed along the coasts of Brittany (France) using a total of 12 microsatellites, 9 for Laminaria hyperborea and 11 for Laminaria digitata, of which 8 amplified in both species. The genetic diversity and connectivity of L. hyperborea populations was greater than that of L. digitata populations in accordance with the larger cross-shore distribution width along the coast and the greater depth occupied by L. hyperborea populations in contrast to L. digitata populations. In addition, marginal populations showed reduced genetic diversity and connectivity, which erased isolation-by-distance patterns in both species. As L. dig...本研究以两种近缘海带为研究对象，系统探究其遗传结构模式，旨在明确潮间带分布宽度、带状分布格局、纬度分布范围以及历史因素如何共同塑造了二者截然不同的遗传多样性格局。本研究采用层级化采样方案，对法国布列塔尼沿岸同域分布的这两种海带的遗传多样性与结构模式开展对比分析；实验共使用12个微卫星（microsatellite）标记，其中9个适用于掌状海带（Laminaria hyperborea）、11个适用于指状海带（Laminaria digitata），另有8个标记可在两个物种中均实现扩增。研究结果显示，掌状海带种群的遗传多样性与连通性均高于指状海带种群，这与其更宽的潮间带横向分布范围以及更深的栖息水深相契合。此外，边缘种群的遗传多样性与连通性均有所降低，这消除了两个物种中的距离隔离（isolation-by-distance）格局。就L. dig...