一种环境敏感型造礁石珊瑚Pocillopora sp.共生虫黄藻和细菌的生态特征  

Ecological characteristics of symbiotic Symbiodiniaceae and bacteria in an environmentally sensitive reef-building coral Pocillopora sp.

作　　者：梁甲元 邓传奇 许勇前 覃良云 陈金妮 葛瑞琪 黄学勇 余克服 Liang Jiayuan;Deng Chuanqi;Xu Yongqian;Qin Liangyun;Chen Jinni;Ge Ruiqi;Huang Xueyong;Yu Kefu(School of Marine Sciences,Guangxi University,Nanning 530004,China;Guangxi Laboratory on the Study of Coral Reefs in the South China Sea,Nanning 530004,China)

机构地区：[1]广西大学海洋学院,广西南宁530004 [2]广西南海珊瑚礁研究重点实验室,广西南宁530004

出　　处：《海洋学报》2022年第2期102-112,共11页

基　　金：国家自然科学基金(42090041,42030502);广西自然科学基金(2018GXNSFAA281328)。

摘　　要：在气候和人类活动的长期影响下,南海珊瑚礁演变出生境各异的珊瑚礁生态系统。珊瑚对特殊生境的适应离不开体内共生微生物类群的调节。分析共生微生物的生态特征有助于了解珊瑚的环境适应机制,同时可以对珊瑚未来的进化趋势做出评估。本研究从南海低纬度的南沙群岛(NS)和西沙群岛(XS)以及相对高纬度的海南陵水(LS)3个珊瑚礁区采集一种环境敏感型造礁珊瑚Pocillopora sp.,分析关键共生微生物(虫黄藻和细菌)的群落结构特征和生物量以及与环境的相关性。结果表明:(1)共生虫黄藻的群落组成在NS、XS与LS之间存在较大差异,NS和XS珊瑚共生虫黄藻的主导系群分别为D1、C1d和C42,而LS则为C42、C1d、C1p、C1和C1t;(2)共生细菌的群落组成均以变形菌(Proteobacteria)、拟杆菌(Bacteroidetes)和厚壁菌(Firmicutes)为主导系群,而具有光合作用功能的蓝细菌(Cyanobacteria)则随着纬度的升高,其相对丰度显著升高(从NS的0.95%到LS的8.18%,p<0.05);(3)在细胞数量方面,随着纬度的升高,共生虫黄藻的密度显著升高(从(3.39±0.49)×10^(6)cells/cm^(2)升至(8.90±0.65)×10^(5)cells/cm^(2),p=0.001<0.05),在相对高纬度的LS同样有着更高的珊瑚共生细菌16S rRNA基因拷贝数(p=0.001<0.05);(4)环境因子相关性分析表明,具有潜在耐热性质的虫黄藻亚系群D1与海表温度和透明度呈正相关,而在LS珊瑚中占主导的虫黄藻C42以及蓝细菌的相对丰度则与海表温度呈显著负相关,与营养盐浓度呈显著正相关。本研究对南海的环境敏感型珊瑚Pocillopora sp.的环境适应微生态机制以及未来进化趋势提供了一个较全面的认识。Under the long-term influence of climate change and human activities,coral reefs have evolved into special ecosystems with different habitats in the South China Sea.However,the adaptation of corals to special habitats is inseparable from the regulation of endosymbiotic microorganisms.The analysis of ecological characteristics of endosymbiotic microorganisms could help to understand the mechanism of coral host adaptation to environmental changes and the evolutionary trend.In this study,an environmentally sensitive reef-building coral Pocillopora sp.was collected from low latitude Nansha Islands (NS) and Xisha Islands (XS) and the relatively high latitude Hainan Lingshui (LS) in the South China Sea.The community composition and cells density,and environmental correlation of key endosymbiotic microorganisms (Symbiodiniaceae and bacteria) were analyzed.The results showed that:(1) there were great differences in the community composition of Symbiodiniaceae subclades among NS,XS,and LS.The dominant subclades in Pocillopora sp.from NS and XS were D1,C1d,and C42 respectively,while those from LS were C42,C1d,C1p,C1,and C1t;(2) the dominant bacterial compositions included Proteobacteria,Bacteroidetes,and Firmicutes in coral samples from different reef areas,while the relative abundance of Cyanobacteria with photosynthetic function increased significantly with the increase of latitude (from 0.95%of NS to 8.18%of LS,p<0.05);(3) in terms of the number of microbial cells in coral,the density of Symbiodiniaceae increased significantly with the increase of latitude (from (3.39±0.49)×10^(5)cells/cm^(2)to (8.90±0.65)×10^(5)cells/cm^(2)coral surface area,p=0.001<0.05),and there was also a higher absolute number of 16S rRNA gene copies in endosymbiotic bacteria in the relatively high latitude LS (p=0.001<0.05);(4) the correlation analysis of environmental factors showed that Symbiodiniaceae subclade D1 with potential thermal tolerance was positively correlated with sea surface temperature and transparency,while subclade C42 and

关 键 词：造礁珊瑚 蓝细菌 南海 环境适应性 虫黄藻密度 

分 类 号：Q938.8[生物学—微生物学]