【摘要】 以2016年第7次北极科学考察期间在不同海域采集到的形态各异的水螅样品为研究对象,初步描述了样品的形态特征,并且利用DNA条形码序列进行了分子鉴定。基于16SrRNA基因序列构建的系统进化树表明,S12,NB06,R01和NB05属于桧叶螅科桧叶螅属,R08和B08为钟形螅科薮枝螅属,而且不同种的水螅均以较高的置信度聚类为一个稳定的分支。因此16SrRNA序列可以作为DNA条形码用于这2属的水螅的分类鉴定。桧叶螅的COI序列扩增较困难,不宜作为DNA条形码用于该属的鉴定,而薮枝螅的COI序列则较易扩增。基于16S rRNA和COI序列的长薮枝螅种间遗传距离均远大于种内遗传距离,存在明显的条形码间隙。且薮枝螅基于COI序列的种内遗传距离比16SrRNA基因的更大,认为COI序列可作为薮枝螅不同地理起源的分析鉴定依据。更多还原

【Abstract】 In this paper,six hydroids collected from different stations in the Seventh Chinese Arctic Scientific Expedition in 2016,were classified by DNA barcoding.And some general features were described.Phylogenetic trees of the mitochondrial 16 SrRNA genes revealed that S12,NB06,R01 and NB05 are assigned to Sertularia(Sertulariidae),R08 and B08 are Obelia(Campanulariidae).Moreover,specific species of hydroids are clustered into one stable clade supported by high bootstrap values.Hence,16 SrRNA gene can be used as a DNA barcode to identify the two genera.The COI gene is unsuitable as a DNA barcode because it is hard to be amplified in Sertularia.While for Obelia,the COI genes are easy to be amplified.The intraspecific genetic distance is far larger than the Interspecific genetic distance based on the two genes of Obelia longissima,and the Interspecific based on COI genes is larger than on 16 SrRNA sequences.Therefore the COI sequence appears to be an effective marker in the identification of different geographical origin strains for Obelia.更多还原