海南几种大型绿藻18S rRNA基因的克隆与序列分析

姜芳燕+黄海+杨宁+马军

摘 要 对海南沿岸采集到的团集刚毛藻（Cladophora glomerata）、细毛横丝藻（Acrochaete leptochaete）、石莼（Ulva reticulata）和长茎葡萄蕨藻（Caulerpa lentillifera）进行了形态学观察，采用18S rRNA通用引物，通过PCR技术，从这4种绿藻的基因组中扩增到各自的18S rRNA基因序列，并测序。与Genebank中已收录的6种绿藻18 S rRNA基因序列进行比较分析，所得10种绿藻的18S rRNA基因長度为727 bp，变异位点为266个，保守位点为453个。刚毛藻目与蕨藻目的遗传距离最大，为0.376；刚毛藻属内的种间遗传距离最小，为0.010。采用NJ法构建的系统进化树的拓扑结构显示：细毛横丝藻、葡枝横丝藻、石莼、礁膜、羽状尾孢藻和皱溪菜聚为一支；团集刚毛藻与扭曲刚毛藻单独聚为一支；长茎葡萄蕨藻与总状蕨藻聚为一支。说明18S rRNA序列可以作为大型绿藻系统发育研究的分子标记。

关键词 团集刚毛藻 ；细毛横丝藻 ；石莼 ；长茎葡萄蕨藻 ；18S rRNA

中图分类号 Q75 文献标识码 A Doi：10.12008/j.issn.1009-2196.2017.06.011

Cloning and Sequence Analysis of 18S rRNA Genes of

Several Large Green Algae in Hainan Province

JIANG Fangyan1） HUANG Hai1） YANG ning2） MA Jun1）

（1 Hainan Key Laboratory of Tropical Marine Fishery Resources Protection and Utilization，

Hainan Tropical Ocean University， Sanya， Hainan 572022；

2 Sanya Science & Technology Academy of Winter Breeding and Multiplication，

Sanya， Hainan 572000）

Abstract Large green algae Cladophora glomerata， Acrochaete leptochaete， Ulva reticulata， and Caulerpa lentillifera collected from the coast of Hainan province were observed morphologically. With 18S rRNA as universal primer， the genes from these 4 large green algae were amplified to 18 S rRNA gene sequence by PCR. A comparative analysis was made of 18S rRNA gene sequences among the 4 green algae selected and the 6 green algae from the Genebank. The results showed that the 18S rRNA gene sequences of these 10 green algae were 727 bp in length with 266 variable sites and 453 conserved sites. The maximum genetic distance between Cladophrales and Codiales was 0.376. The genetic distance among the species of genus Cladophora was 0.010， the shortest. The topology of phylogenetic tree constructed by NJ method suggested that A. leptochaete， A. repens， U. reticulata， M. nitidum， U. penicilliformis， and P. crispa were clustered into one group； C. glomerata and C. coelothrixwere into another group； C. lentillifera and C. racemosa into another group. This indicated that 18S rRNA sequence could be used as a molecular marker for phylogenetic research of large green algae.

Keywords Cladophora glomerata ； Acrochaete leptochaete ； Ulva reticulata ； Caulerpa lentillifera ； 18S rRNA.

大型海藻是一类重要的海洋生物资源，是海洋生态系统的重要组成部分，在海洋生态系统物质循环和维持海洋生态平衡中发挥着重要作用[1]。丁兰平等[2]在对中国南海多个地区开展野外调查的基础上，通过研究与历史资料整理发现，中国目前绿藻门海藻共计有11目21科48属211个种及变种，其中南海绿藻门有9目16科41属180种及变种、变型，其绿藻多样性占全国的85.31%，表明南海是中国绿藻多样性最丰富的地区。由于生长环境的不同，大型绿藻的藻体形态及结构存在着广泛的变异，因此，单从传统的形态学特征对其进行系统分类有一定的局限性。……