徐闻角孔珊瑚系统发育关系

ANALYSIS OF PHYLOGENY ON GONIOPORA IN XUWEN USING ITS GENE

本文以徐闻4种角孔珊瑚为研究对象,研究了其ITS基因各区段的长度,碱基组成及(G+C)含量,计算了4种角孔珊瑚间的遗传距离并构建了其系统发育树。结果显示,4种角孔珊瑚的ITS基因长度在592～599bp之间,4种角孔珊瑚ITS区的(G+C)平均含量在48.5%,二异角孔珊瑚的ITS基因各个区段的(G+C)的含量与其他3种珊瑚差异较大,ITS1为47.1%,ITS2为49.2%。碱基组成分析结果显示4种角孔珊瑚的ITS区在碱基使用上没有偏向性。二异角孔珊瑚与其他三种角孔珊瑚的遗传距离分别为0.235、0.242、和0.235,远远高于平均遗传距离0.123,UPGMA聚类分析也显示二异角孔珊瑚在进化树上成为单独的一支。

The ITS（internal transcribed spacer） sequences of 4 species in Goniopora were obtained by PCR technique and analyzed by MEGA4.1 software.In this study,the results showed that ITS sizes of the tested 4 species were ranged from 592bp to599bp,the ranges of（G＋C） contents of ITS were 48.0%~49.1%,and the average content was 48.5%.The ITS gene section（G ＋ C） contents of Goniopora duofasciat were larger differences with the other three corals,ITS1 was 47.1%,ITS2 is 49.2%.Based composition analysis revealed that 4 species in the base of coral in the ITS area with no bias.The genetic distances of Goniopora duofasciat with the other three species were 0.235,0.242,and 0.235,however far higher than the average genetic distance 0.123.In addition,there were two branches in the constructed phylogenetical tree,in which Goniopora duofasciat presented an independent branch,and the other three were in another.The results provide an important basis for the further study on the confirmation of phylogenetic position of Goniopora and Poritidae.