| 摘要: |
| 共生藻属(Symbiodinium)主要指一类与无脊椎动物或原生生物共生的甲藻，是热带和亚热带海洋生态系统常见物种。本研究从中国沿海和一艘停靠在厦门港的货轮压舱水中分离出了4株贪食共生藻(Symbiodinium voratum)。贪食共生藻运动细胞较小(长9.7±1.3 μm，宽8.7±0.9 μm)，能够产生不动细胞(直径11.4±0.3 μm)和二分裂细胞(直径12.2±0.6 μm)。扫描电子显微镜下运动细胞顶部有一个单线长甲板型顶沟复合体(Elongate Apical Vesicle, EAV)，其甲板方程式为x, EAV, 4′5′, 5a6a, 9′′, ?s, ?c, 6′′′, 2′′′′。透射电子显微镜显示其具有E型眼点、单茎的大淀粉核、扁平囊泡组成的高尔基体和三层膜组成的叶绿体类囊体。4株贪食共生藻的核糖体基因(SSU rDNA， ITS和LSU rDNA)、 cp23S和cob序列完全一致。利用最大释然法和贝叶斯方法构建的基于LSU rDNA序列的系统发育树显示：中国沿海和世界其他地方的贪食共生藻很好的聚类在一起，共同组成系群E。中国株系和其他地方贪食共生藻的遗传分化很小，显示它们之间有频繁的基因交流。 |
| 关键词: 海洋生物学 甲藻 贪食共生藻 形态分类 分子特征 |
| DOI：10.3969/J.ISSN.2095-4972.2021.02.002 |
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| 基金项目:福建省自然科学基金资助项目（2019J05150）;国家自然科学基金资助项目（41676117） |
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| Morphology, ultrastructure and molecular characteristics of Symbiodinium voratum in coastal waters of China |
| ZHANG Wei,LUO Zhao-he,GAO Yue,GU Hai-feng |
| (Third Institute of Oceanography, MNR, Xiamen 361005, China;State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, China) |
| Abstract: |
| Symbiodinium species live predominantly in mutualistic symbiosis with various invertebrate and protist hosts, and they commonly exist in subtropical and tropical marine ecosystems. Four strains of S. voratum were isolated from the coastal waters of China and from a cargo ship ballast water. Motile cells of S. voratum are small (length 9.7 ± 1.3 μm; width 8.7 ± 0.9 μm), and the immotile cells (diameter 11.4 ± 0.3 μm) and doublet cells (diameter 12.2 ± 0.6 μm) are often packed with storage products. Scanning electron microscope observations reveal the presence of a single elongated apical vesicle (EAV), which exhibits the Kofoidean plate tabulation: x, EAV, 4′-5′, 5a-6a, 9′′, ?s, ?c, 6′′′, 2′′′′. Transmission electron microscope examination shows the presence of a type E eyespot and singlestalked pyrenoid. The golgi is composed of many dictyosomes and the chloroplast thylakoids are in stacks of three. Four S. voratum strains share identical SSU rDNA, ITS, LSU rDNA, cp23S and cob sequences. Molecular phylogeny based on LSU rDNA sequences using maximum likelihood and Bayesian inference revealed that S. voratum from China and other parts of world formed a well resolved clade E. The high genetic similarity among Chinese strains and those from elsewhere suggest frequent gene exchange among them. |
| Key words: marine biology dinoflagellate Symbiodinium voratum morphological taxonomy molecular characteristc |
