7株盐藻的5.8S rDNA和ITS序列及RAPD分析

Analysis of 5.8S rDNA-ITS Sequences and RAPD of Seven Dunaliella sp.

研究的7株盐藻(株号分别为A85、A57、A83、A43、C43、A121和A124)均含有2根鞭毛,细胞形状均为长椭圆形或梨形,眼点不明显。在高盐度培养条件下7株盐藻甘油合成能力均明显增强,这与描述的绿色杜氏藻特征相似。为了进一步确定这些盐藻的分类地位,了解其与其它杜氏盐藻种的亲缘关系,本研究PCR扩增7株盐藻的5.8S rDNA和ITS序列,并完成序列测定,将从Genbank搜索的27条已定种杜氏盐藻的相应序列与7条扩增序列同时进行分析,构建进化树,结果表明,7株盐藻均与绿色杜氏藻(D.viridis)亲缘关系最为密切,7株盐藻可能均属于绿色杜氏藻,其中A85、A57和A83亲缘关系最近,A121和A124关系最为密切。筛选的11个随机引物进行7株盐藻RAPD分析的结果与采用5.8SrDNA和ITS序列分析的结果基本一致。

All of the studied seven Dunaliella sp.(A85,A57,A83,A43,C43,A121 and A124) have two flagella,with cells long ellipsoidal and/or pyriform,and stigma diffuse,and the content of glycerol within the seven Dunalliella sp.increase evidently under high salinities,which is similar to that of D.viridis.In order to determine the taxonomic status of seven Dunalliella strains and their relationship with other Dunaliella species,the ribosome 5.8S rDNA and ITS sequences of these Dunalliella strains were sequenced,and compared with 27 sequences(of 8 Dunaliella species) from Genebank.UPMGA phylogenetic tree revealed that all the seven Dunalliella strains clustered in the same clad with D.viridis,which suggested that the studied Dunalliella strains might belong to D.viridis.Within the 7 studied strains,A85 and A57 and A83 were clustered to a clad,while A121 and A124 were clustered to another clad,which was further supported by RAPD analysis using 12 random primers.