基于线粒体16SrRNA基因的14种造礁石珊瑚系统发育关系分析

Phylogenetic Analysis for 14 Species of Reef-building Corals Based on 16SrRNA genes

通过16SrRNA基因特异扩增测序,对惠州大亚湾大辣甲岛和小辣甲岛附近海域14种造礁石珊瑚16SrRNA基因片段序列进行了比较分析。结果表明,该片段序列的平均A+T含量为63.5%,所有物种的序列碱基AT含量大于GC含量,序列都处于高度饱和的状态。14种造礁石珊瑚的平均遗传距离为0.179。采用NJ、ML和ME法构建系统发育树,结果显示蜂巢珊瑚科单独作为分支处于发育树的基部,而第二支分支包括菌珊瑚科、鹿角珊瑚科、滨珊瑚科和枇杷珊瑚科。裸肋珊瑚科的腐蚀刺柄珊瑚聚到了蜂巢珊瑚科中,与传统形态学分类存在差异,提示造礁石珊瑚表型的变异性可能对传统分类存在影响。

Partial sequences of 16S rRNA from 14 species of reef-building corals in Dalajia Island andXiaolajia Island were amplified and sequenced, and Base ratio and genetic distances were analyzed. Theresult indicated that the average A+T of this region accounted for 63.5% from 14 species; A+T contentsof 16S rRNA fragments were higher than G+C obviously. The sequences of 16S rRNA fragments had ahigh degree of saturation.The average genetic distance was 0.179 from 14 species. According to theNeighbour-joining,Maximum-likelihood and Minimum-evolution trees,the separated Faviidae was theroot clade, and the second clade was composed of Agariciidae, Acroporidae , Poritidae andOculinidae.The Hydnophora exesa of Merulinidae merged into the Faviidae.The result suggested thatmorphological classification may be limited by coral skeletons plasticity.