Asymmetric genetic exchange in the brown seaweed Sargassum fusiforme (Phaeophyceae) driven by oceanic currents

• Published in: Marine biology Vol. 160; no. 6; pp. 1407 - 1414
• Main Authors: Hu, Zi-Min, Zhang, Jie, Lopez-Bautista, Juan, Duan, De-Lin
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.06.2013; Springer; Springer Nature B.V
• Subjects: Algae; Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Biomedical and Life Sciences; Freshwater & Marine Ecology; Fundamental and applied biological sciences. Psychology; Genetics; Life Sciences; Marine; Marine & Freshwater Sciences; Marine biology; Microbiology; Ocean currents; Oceanography; Original Paper; Phaeophyceae; Sargassum fusiforme; Sea water ecosystems; Synecology; Zoology; Korea, Rep; INW, Donghai Sea, Kuroshio Current; ISEW, South China Sea; INW, Donghai Sea; Brown Seaweed; Kuroshio Current; Genetic Connectivity; Taiwan Warm Current; Warm Current; Exchange; Heterokontophyta; Algae; Genetics; Marine alga; Sargassum; Phaeophyceae
• ISSN: 0025-3162; 1432-1793
• DOI: 10.1007/s00227-013-2192-x

Geological phenomena (e.g. drastic sea level fluctuations during the Quaternary Ice Age in the Northern Hemisphere) have been demonstrated to intensively affect the biogeographic patterns and tempo-spatial compositions of genetic diversity of marine organisms. However, it is poorly understood whether contemporary factors such as oceanic surface currents have also shaped inter-regional population genetics of specific coastal marine flora, with or without limited dispersal capability. In this study, we determined mtDNA Cox1 gene sequences of the brown seaweed Sargassum fusiforme from nine populations along the Chinese coast and one population from the west coast of South Korea, in an effort to understand what factors are contributing to their current genetic structure and geographic distribution patterns. Genetic analyses indicated a deep genetic break between the Yellow-Bohai Sea (YBS) and the other two marginal seas, the East China Sea (ECS) and the South China Sea (SCS). In particular, the amount of genetic exchange from the SCS to each of the ECS and YBS was significantly higher than that from the opposite directions. Our analyses supports the hypothesis that biogeographic patterns of genetic variation in S. fusiforme are probably an interactive consequence of post-glacial colonization from two scattered refugia driven by the offshore Kuroshio Current and asymmetric gene flow among adjacent sea margins.