Huang Wen, Chen Yinmin, Wu Qian, Feng Yi, Wang Yonggang, Lu Zhiying, Chen Jinlian, Chen Biao, Xiao Zunyong, Meng Linqing, Huang Xueyong, Wang Yan, Yu Kefu
Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning 530004, China.
The Ocean College, Hainan University, Haikou 570228, China.
Mar Pollut Bull. 2023 Aug;193:115147. doi: 10.1016/j.marpolbul.2023.115147. Epub 2023 Jun 16.
Under the dual effects of climate change and anthropogenic activities, coral reefs in the South China Sea (SCS) are at serious risk of degradation. Galaxea fascicularis is a widely distributed species in the SCS, and the study of its genetics, survival, and adaptability is conducive to further understanding the future characteristics of coral reefs in the SCS. In this study, 146 G. fascicularis samples were selected from 9 survey stations across 12 latitudes in the SCS, and 8 pairs of microsatellite markers were used to characterize their genetic diversity and structure. The results showed moderate genetic diversity index values (A = 3.444-4.147, H = 0.634-0.782, H = 0.367-0.586). The AMOVA results and pairwise F values showed a moderate level of genetic differentiation (Φ = 0.119, P < 0.05) among G. fascicularis populations in the SCS, whereas its genetic structure showed high genetic differentiation (F = 0.062-0.225) among relatively high-latitude populations (n = 3) and low genetic differentiation (F = 0.012-0.064) in low-latitude populations (n = 6). The living environment of relatively high-latitude populations is disturbed by high-intensity human activities, leading to the specialization of local populations. Mantel test results showed a significant positive correlation between genetic differentiation among G. fascicularis populations and sea surface temperature (SST) variance (R = 0.4885; Mantel test, p = 0.010 < 0.05) in addition to geographical distance (R = 0.1134; Mantel, test p = 0.040 < 0.05), indicating that SST and geographical isolation were primary factors affecting the genetic structure of this species in the SCS. The lower genetic diversity and limited gene flow of G. fascicularis indicate limited genetic adaptation, and corresponding vulnerability may be more pronounced under future environmental changes. These findings provide a theoretical basis for the conservation and restoration of coral reefs in the SCS.
在气候变化和人类活动的双重影响下，南海的珊瑚礁面临着严重的退化风险。丛生盔形珊瑚是南海广泛分布的物种，对其遗传学、生存和适应性的研究有助于进一步了解南海珊瑚礁的未来特征。本研究从南海12个纬度的9个调查站点选取了146个丛生盔形珊瑚样本，使用8对微卫星标记来表征其遗传多样性和结构。结果显示遗传多样性指数值适中（A = 3.444 - 4.147，H = 0.634 - 0.782，H = 0.367 - 0.586）。方差分析结果和成对F值显示南海丛生盔形珊瑚种群间存在中等程度的遗传分化（Φ = 0.119，P < 0.05），而其遗传结构显示相对高纬度种群（n = 3）间遗传分化较高（F = 0.062 - 0.225），低纬度种群（n = 6）间遗传分化较低（F = 0.012 - 0.064）。相对高纬度种群的生存环境受到高强度人类活动的干扰，导致当地种群的特化。曼特尔检验结果表明，除了地理距离（R = 0.1134；曼特尔检验，p = 0.040 < 0.05）外，丛生盔形珊瑚种群间的遗传分化与海表温度（SST）方差之间存在显著正相关（R = 0.4885；曼特尔检验，p = 0.010 < 0.05），这表明海表温度和地理隔离是影响南海该物种遗传结构的主要因素。丛生盔形珊瑚较低的遗传多样性和有限的基因流表明其遗传适应性有限，在未来环境变化下相应的脆弱性可能更加明显。这些发现为南海珊瑚礁的保护和恢复提供了理论依据。
