琼枝白化特征及其附生菌群多样性分析  

Characterization of Bleached Betaphycus gelatinae and Analysis of Its Epiphytic Bacterial Diversity

作　　者：马艺丹 唐磊[1,2,3] 王一帆 张帅[3,4] 王振东 茅云翔[3,4] 莫照兰 Ma Yidan;Tang Lei;Wang Yifan;Zhang Shuai;Wang Zhendong;Mao Yunxiang;Mo Zhaolan(Key Laboratory of Tropical Aquatic Germplasm of Hainan Province,Sanya Oceanographic Institution,Ocean University of China,Sanya 572024,China;Key Laboratory of Marine Genetics and Breeding,Ministry of Education,College of Marine Life Science,Ocean University of China,Qingdao 266003,China;Yazhou Bay Innovation Institute,Hainan Tropical Ocean University,Sanya 572024,China;Key Laboratory of Utilization and Conservation for Tropical Marine Bioresource,Ministry of Education,College of Fisheries and Life Science,Hainan Tropical Ocean University,Sanya 572022,China)

机构地区：[1]中国海洋大学三亚海洋研究院海南省热带水产种质重点实验室,海南三亚572024 [2]中国海洋大学海洋生命学院海洋生物遗传育种教育部重点实验室,山东青岛266003 [3]海南热带海洋学院崖州湾创新研究院,海南三亚572024 [4]海南热带海洋学院水产与生命学院热带海洋生物资源利用与保护教育部重点实验室,海南三亚572022

出　　处：《中国海洋大学学报（自然科学版）》2024年第5期52-62,共11页Periodical of Ocean University of China

基　　金：国家自然科学基金项目(32060829);中央高校基本科研业务费专项(202064006);国家重点研究发展计划项目(2020YFD0901101);海南省自然科学基金项目(320QN292)资助。

摘　　要：2021-2022年,海南昌江养殖的琼枝(Betaphycus gelatinae)白化现象频发,造成了一定的经济损失,影响了海洋生态环境。为探究白化琼枝的特征和附生菌群落结构的差异,本研究分析了不同状态琼枝的形态差异;测定了色素含量、光合生理、生理生化等指标;分离、鉴定了不同状态琼枝表面的可培养附生细菌,同时采用16S rRNA高通量测序技术分析了健康琼枝(BgR)和白化琼枝(BgW)表面附生细菌的α多样性、β多样性以及菌群群落结构组成。研究显示,白化琼枝藻体的皮层组织结构遭到破坏,色素含量、最大光合效率(QY_max)显著降低,活性氧(ROS)、超氧化物歧化酶(SOD)、丙二醛(MDA)、脯氨酸(Pro)含量显著降低(p<0.05);BgW的可培养附生细菌数量(2.76×10^(7) cfu/g)显著高于BgR(3.3×10^(4) cfu/g),BgR中可培养附生细菌优势菌为鲁杰氏菌属(Ruegeria),BgW中为Yoonia属;高通量测序结果显示,两组样品附生菌群的α多样性指数无显著差异,但BgW的Ace、Chao、Simpson指数均有所升高,相似性分析(ANOSIM)表明,BgR和BgW表面附生菌群之间存在显著差异,比对注释结果共识别出253个OTUs,无色杆菌属(Achromobacter)、琼脂小杆菌属(Agaribacterium)、Hirschia属、Mesoflavibacter属和Aquimarina属是BgR和BgW之间相对丰度差异最显著的细菌类群(p<0.001);BgR的优势菌群为无色杆菌属,BgW的优势菌群为琼脂小杆菌属。本研究首次报道了白化琼枝的特征及表面附生菌群的变化,为进一步探究琼枝白化的原因奠定了基础。In 2021 and 2022,the bleaching of Betaphycus gelatinae has caused seriously economic and ecological losses in Hainan.To clarify the characteristics and causes of the bleaching,physiological parameters and the community structure of epiphytic bacteria of healthy(BgR)and bleached B.gelatinae(BgW)were analyzed.The morphological difference,pigment content,photophysiological and physiological parameters between BgR and BgW were compared.Using high-throughput amplicon sequencing of the 16S rRNA gene,the alpha diversity,beta diversity and structures of the epiphytic microbial communities of BgR and BgW were analyzed as well.The study revealed that cortex cells in BgW were disrupted with significant reduction of pigments and maximum photosynthetic efficiency(QY_max).The reactive oxygen species(ROS),superoxide dismutase(SOD),malondialdehyde(MDA),and proline(Pro)were significantly reduced(p<0.05).The number of culturable epiphytic bacteria in BgW(2.76×10^(7) cfu/g)was remarkably higher than that in BgR(3.3×10^(4) cfu/g).The dominant bacterium in BgR was Ruegeria while that in BgW was Yoonia.The high-throughput sequencing results revealed that no significant difference existed for the alpha diversity indices between microbial communities associated with the two groups of B.gelatinae.However,the Ace,Chao and Simpson index of BgW were higher than those of BgR.Analysis of similarities demonstrated that significant differences in epiphytic microbial communities existed between BgR and BgW.A total of 253 OTUs were identified,and Hirschia,Mesoflavibacter,Aquimarina,Agaribacterium and Achromobacter were the taxa with the most significant differences in relative abundance between BgR and BgW(p<0.001);The dominant bacterium in BgR was Achromobacter while the most dominant bacterium in BgW was Agaribacterium.Our findings featured the B.gelatinae bleaching for the first time and provided data supporting the clarification of the function of microbial community in B.gelatinae bleaching.

关 键 词：琼枝 白化 附生细菌 多样性 生理生化 病理特征 

分 类 号：S946.3[农业科学—水产养殖]