海南省2个冬青叶马尾藻种群的多样性及分子系统学研究

Diversity and phylogenetic analysis of two populations of Sargassum ilicifolium(Fucales, Phaeophyceae)in Hainan

为了解海南省冬青叶马尾藻不同地理种群的多样性,从潭门镇和长坡镇收集到12份冬青叶马尾藻样品,通过PCR扩增和测序获得了其cox1(细胞色素C氧化酶亚基1)、rbc L(1,5-二磷酸核酮糖羧化酶/加氧酶大亚基)及ITS(内转录间隔区)序列。多序列比对显示,2个种群的冬青叶马尾藻的cox1、rbc L序列很保守,未发现多态性位点;而ITS序列变异较大,在碱基组成和序列长度上均有丰富的多态性。根据ITS的序列特征将所分析样品分为A、B和C 3个类群。系统进化分析显示,3个类群能以较高的置信度与数据库中其他地域来源的冬青叶马尾藻聚为一支,其中A、B类群的亲缘关系非常近,而C类群与其他地域来源的冬青叶马尾藻更相似。

In order to understand diversities among different geographic populations of Sargassumilicifolium in Hainan,12 S. ilicifolium individuals were collected from Tanmen and Changpo Town,thensequences of cox1, rbcL and ITS were obtained through PCR amplification and sequencing. Multiplesequence alignment showed that cox1 and rbcL were conserved among the 12 individuals,and nopolymorphism site were found within the two populations;but relative abundant polymorphisms wereidentified both in variation of the length and base composition among different ITS sequences. Thus,the12 S. ilicifolium individuals were divided into three groups (A,B and C) based on variations amongtheir ITS sequences. Phylogenetic analysis revealed that the three groups were first clustered togetherwith S. ilicifolium individuals from other regions of the world. Additionally,groups A and B were moreclosely related to each other;but group C showed a closer genetic relationship with other geographicindividuals of S. ilicifolium.