| 摘要: |
| 本文利用18S rRNA基因对4株经形态学初步鉴定的梅尼小环藻(Cyclotella meneghiniana)进行了分子鉴定。结果显示, 这4株分离自淡水环境(2株)和海水环境(2株)的梅尼小环藻的18S rRNA基因序列基本一致, 并与已经报道的梅尼小环藻(登录号为GQ148712和AY496212)聚为一支, 不同方法所构建的系统树的支持率分别为99%(邻接法)和98%(最大似然法), 表明这4 株来自不同环境的藻为同一物种——梅尼小环藻。随后作者利用扫描电镜技术在亚显微水平上对这4株梅尼小环藻进行了观察, 结果显示: 梅尼小环藻淡水株和海水株具有相当不同的亚显微结构特征。生活在海水的梅尼小环藻藻株具有更大的细胞以及更多的中央支持突。此外, 本文还对造成梅尼小环藻种内高水平形态差异的原因以及18S rRNA基因序列是否可以作为小环藻属物种鉴定的分子标记做了分析和讨论。 |
| 关键词: 硅藻 梅尼小环藻(Cyclotella meneghiniana) 亚显微结构 扫描电镜 18S rRNA |
| DOI：10.11759/hykx20161023002 |
| 分类号: |
| 基金项目:广东省海洋渔业科技与产业发展专项(A201508B08) |
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| Ultrastructure of the centric diatom Cyclotella meneghiniana: morphological differences between freshwater and seawater strains |
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LI Chang-ling,CHEN Jian-bing,HUANG Xiang-hu
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| Abstract: |
| In this paper, four strains were identified using 18S rRNA gene sequences. The results show that the 18S rRNA gene sequences of these four strains (two come from freshwater and two from seawater) are very similar and that these four strains are closely related to Cyclotella meneghiniana (GQ148712 and AY496212) with high support (99/98 for neighbor joining/maximum likelihood). According to the molecular results, the four strains are of the same species, i.e., C. meneghiniana. Then, the ultrastructure of the four strains was studied using scanning electron microscopy (SEM). The results show that the ultrastructure of freshwater C. meneghiniana is different from that of seawater C. meneghiniana, which also have larger cells and contain higher amounts of central fultoportula. In addition, this paper analyzed the causes of high-level morphology differences within C. meneghiniana species and discussed whether the 18S rRNA gene can be used as a molecular marker for the identification of Cyclotella species. |
| Key words: diatom Cyclotella meneghiniana ultrastructure scanning electron microscopy 18S rRNA |
