High genetic differentiation and moderate genetic diversity of the degenerative branching coral Pocillopora verrucosa in the tropical South China Sea

Ming Li; Wen Huang; Qian Wu; Yi Feng; Yinmin Chen; Kefu Yu; Biao Chen; Enguang Yang; Linqing Meng; Xueyong Huang; Xin Wang

doi:10.1016/j.scitotenv.2022.153076

High genetic differentiation and moderate genetic diversity of the degenerative branching coral Pocillopora verrucosa in the tropical South China Sea

Sci Total Environ. 2022 May 1:819:153076. doi: 10.1016/j.scitotenv.2022.153076. Epub 2022 Jan 14.

Authors

Ming Li¹, Wen Huang², Qian Wu³, Yi Feng³, Yinmin Chen³, Kefu Yu⁴, Biao Chen³, Enguang Yang³, Linqing Meng³, Xueyong Huang³, Xin Wang⁵

Affiliations

¹ 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; Forestry College, Guangxi University, Nanning 530004, China.
² 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. Electronic address: wenhuang@gxu.edu.cn.
³ 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.
⁴ 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; Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai 519080, China. Electronic address: kefuyu@scsio.ac.cn.
⁵ 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; Gunagxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Beihai 536000, China.

PMID: 35038534
DOI: 10.1016/j.scitotenv.2022.153076

Abstract

Global warming is causing rapid degradation of coral reefs, among which branching corals are degrading the fastest. An assessment of coral genetic diversity and adaptive potential provides a basis for coral reef protection. In this study, we selected the branching coral Pocillopora verrucosa, a widely distributed species in the tropical South China Sea (SCS), to carry out population genetic studies. To analyze the genetic diversity and structure of 319 P. verrucosa samples from 10 populations in 4 SCS regions, twelve pairs of microsatellite primers and two nuclear markers, ITS and β-tub, were selected. Microsatellite marker results showed moderate genetic diversity for P. verrucosa in the SCS, but relatively low diversity in Dazhou Island and Yongxing Island. The haplotype network showed that P. verrucosa in the SCS was derived from two ancestors, which may be linked to geographical isolation in the Pleistocene glacial period. AMOVA (Φ_ST = 0.3375) and F_ST pairwise analysis results based on β-tub showed that the populations were highly differentiated, with most F_ST values (21/45) > 0.25. Yongxing and Qilianyu Islands populations were significantly different from those in the Xisha area. Mantel test results showed that genetic differentiation among P. verrucosa populations was significantly and positively correlated with both mean sea surface temperature (SST) and SST variance, and was not correlated with distance, chlorophyll-a, or turbidity. The reproductive mode of brooding planulae was an important factor contributing to high genetic differentiation among populations. The moderate genetic diversity of SCS P. verrucosa indicates that this population has a certain genetic potential in the context of global changes, but the high genetic differentiation between populations increases the risk of local degradation or extinction. This study provides a theoretical basis for the protection and restoration of SCS coral reefs.

Keywords: Genetic connectivity; Global warming; Phylogeography; Population genetics; Reef-building corals.

MeSH terms

Animals
Anthozoa* / genetics
Coral Reefs
Genetic Variation
Global Warming
Microsatellite Repeats