Populations of many Mediterranean marine species show a strong phylogeographic structure, but the knowledge available for native seaweeds is limited. We investigated the genetic diversity of the green alga Halimeda tuna based on two plastid markers (tufA gene and a newly developed amplicon spanning five ribosomal protein genes and intergenic spacers, the rpl2‐rpl14 region). The tufA sequences showed that Mediterranean H. tuna represents a single, well‐defined species. The rpl2‐rpl14 results highlighted a genetic separation between western and eastern Mediterranean populations; specimens collected from widely scattered locations in the Adriatic/Ionian region shared a haplotype unique to this region, and formed a group separated from all western Mediterranean regions. Specimens from Sardinia also formed a unique haplotype. Within the western Mediterranean basin, a gradual shift in the frequency of haplotypes was apparent along a West‐East gradient. Our results represent the first clear evidence of an East‐West genetic cleavage in a native Mediterranean macroalga and offer an interesting perspective for further research into fine‐scale seaweed population structure in the NW Mediterranean Sea.

中文翻译：

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地中海绿色海藻 Halimeda 金枪鱼 (Ulvophyceae, Chlorophyta) 的系统地理学。

许多地中海海洋物种的种群显示出强大的系统地理结构，但可用于本地海藻的知识有限。我们基于两个质体标记（tuf A 基因和新开发的跨越五个核糖体蛋白基因和基因间隔区的扩增子，rpl 2 -rpl 14 区域）研究了绿藻Halimeda 金枪鱼的遗传多样性。tuf A序列表明，地中海金枪鱼代表一个单一的、明确定义的物种。rpl 2- rpl _14 项结果强调了地中海西部和东部种群之间的遗传分离；从亚得里亚海/爱奥尼亚地区广泛分散的地点收集的标本共享该地区独有的单倍型，并形成一个与所有西地中海地区分开的群体。来自撒丁岛的标本也形成了独特的单倍型。在西地中海盆地内，单倍型频率沿东西向梯度逐渐变化。我们的研究结果代表了地中海本土大型藻类中东西向遗传分裂的第一个明确证据，并为进一步研究西北地中海的精细海藻种群结构提供了一个有趣的视角。