Song Xiaohan, Yao Jianting, Roleda Michael Y, Liang Yanshuo, Xu Rui, Lin Yude, Gonzaga Shienna Mae C, Du Yuqun, Duan Delin
State Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266000, China.
Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266200, China.
Plants (Basel). 2025 May 16;14(10):1497. doi: 10.3390/plants14101497.
Understanding population genetic connectivity is crucial for the sustainability and persistence of marine biodiversity. As a fundamental reef-building macroalga of the coastal ecosystem, Decaisne is one of the dominant intertidal seaweeds in the Indo-Pacific region. However, its genetic structure and population connectivity have been poorly recognized. Here, we explored the population genetic structure and genetic connectivity of using chloroplast A, 3-14, and L. Our results indicated low genetic diversity and shallow population genetic structure at the intraspecific level, uncovering five genetic groups with six subdivided lineages in A and two genetic clusters in 3-14. We detected demographic expansion in the last glacial period of the Pleistocene and significantly asymmetric gene flow among different geographical units. We suggest that the southwestward ocean currents under the influence of northeast monsoon in the Indo-Pacific region are the main factor in shaping the present genetic structure, and the asexual reproduction of also plays an important role of the low genetic diversity pattern; in addition, the divergence between genetic clusters might be related to the historical isolation led by the paleoclimate oscillation in the Pleistocene. The Xisha Islands in the northern South China Sea might serve as a potential refugium of , which needs extra attention to conservation management. Given the limitation of sample size, we need to conduct more field work and carry out further research at a larger scale in the future. Our study provided new insights into the theory of population connectivity in the Indo-Pacific region and provided scientific basis for tropical costal seaweed conservation.
了解种群遗传连通性对于海洋生物多样性的可持续性和持久性至关重要。作为沿海生态系统中一种重要的造礁大型藻类，德凯藻是印度-太平洋地区潮间带的优势海藻之一。然而，其遗传结构和种群连通性一直未得到充分认识。在此，我们利用叶绿体A、3-14和L探讨了德凯藻的种群遗传结构和遗传连通性。我们的结果表明，种内水平的遗传多样性较低，种群遗传结构较浅，在叶绿体A中发现了五个遗传组，有六个细分谱系，在3-14中发现了两个遗传簇。我们检测到更新世末次冰期的种群扩张以及不同地理单元间显著不对称的基因流。我们认为，印度-太平洋地区东北季风影响下的西南向洋流是塑造当前遗传结构的主要因素，德凯藻的无性繁殖对低遗传多样性模式也起重要作用；此外，遗传簇之间的分歧可能与更新世古气候振荡导致的历史隔离有关。南海北部的西沙群岛可能是德凯藻的一个潜在避难所，需要在保护管理方面给予特别关注。鉴于样本量的限制，我们未来需要开展更多的野外工作并进行更大规模的进一步研究。我们的研究为印度-太平洋地区种群连通性理论提供了新见解，并为热带沿海海藻保护提供了科学依据。
