Study On Genetic Diversity And Phylogeny Of Poritidae In Xuwen

Seven species,58samples of Poritidae were selected: Porites lutea,Poritesnigrescens, Porites pukoensis, Goniopora columna, Goniopora gracilis, Gonioporaminor and Goniopora duofasciat. In this study, The sequence of ITS gene and partial12SrRNA gene were get, using polymerase chain reaction (PCR), and then analysetheir genetic diversity and phylogenetic relationship.Based on the results of the genetic diversity of the ITS gene, the lengeh of ITS1gene is between187bp-218bp, GC content is bewwen40%~51%. Among thosesamples,48haplotypes were detected, the haplotype diversity index was between0.800~1.000,and the polymorphic loci is between5~62. The average number ofnucleotide differences is between2.067~16.833, the nucleotide diversity index wasbetween0.012~0.094; The ITS2gene were between166bp~250bp in length, GCcontent was between37%~49%, and43haplotypes were detected, haplotype diversityindex was between0.742~1.000. The polymorphic loci was between22~75.and thenumber of average nucleotide differences was between4.463~43.333, the nucleotidediversity was between0.017~0.175. The average nucleotide differences based on theITS2was greater than the results based on the ITS1gene.Otherwise, The variety ofnucleotide diversity based on ITS2gene was greater than the results based on ITS1gene, except for Porites lutea. It is can indicated that the variability of ITS2wasto be greater than ITS1gene in long~term evolutionary process. Among these sevenspecises, The genetic differentiation index based on the ITS gene was between-0.00409~0.12170(p <0.0124), genetic differentiation was not obvious.The5.8S rDNA gene was between141bp and~190bp in length, GC content wasbetween45%~54%. The tree was divide into five parts, and the average geneticdistance is0.187.The phylogenetic tree based on the5.8S rDNA gene was get. Part III,IV and V were consist of singel species groups. The are Porites nigrescens,Goniopora columna and Porites pukoensis respectively.The results of phylogeny relationship based on the12SrRNA gene is that thelength was between659bp~920bp, GC content is between37.8%~40.0%, thegenetic distance was between0.002~0.025, the12SrRNA gene is in relatively conservative in Poritidae.7species of coral have been were divided into threebranches in the phylogenetic tree, Three sepecise of Porites were in the same branch.Goniopora duofasciat was on separate branch, the other three specises of Gonioporawere on the other branch. The monophyly is relatively clear in the phylogenetic tree.Among the Porites genus, Porites lutea and and Porites pukoensis Porites genusPorites branches gather, for Porites nigrescens as a separate one, Goniopora gracilisand Goniopora minor get together,and Goniopora columna was on the separate one.The phylogenetic tree based on12SrRNA gene basically consistent with traditionalclassification system.