Identification Of DNA Barcoding And Phylogenetic Analysis In Hainan Scleractinian Coral Of Genus Acropora

Acropora is the first most species-rich genus of scleractinian coral,which presents high variation and widely distributs in the Indian and Pacific oceans. In this study, the boundaries of species and the phylogenetic relationship were developed and analyzed based on two nuclear markers (PaxC intron and ITS) and two mitochondrial markers (CR,COI) for seven kinds of Acropora in Hainan. The mainly results are listed as followed:1) The genetic diversity and genetic distance based on the nuclear DNA molecular marker were higher than those of mitochondria, and the genetic diversity and genetic distance based on ITS sequences were higher than those of other molecular markers. The interspecific genetic distance between Acropora nasuta and Acropora selago was the smallest based on the nuclear DNA molecular marker, which indicated that the genetic relationship between the two Acropora species was similar.2) 7 specises of Acroporacoral were clustered into four clades based on two kinds of nuclear DNA molecular marker, corresponding arborescent, caespitose,caespito-corymbose and corymbose group morphology. Acropora corymbosa,Acropora millepora, Acropora lutkeni and Acropora nana are well separated based on PaxC molecular marker, but ITS can only identify Acropora lutkeni to specie.Compared with two kinds of nuclear DNA molecular markers, both PaxC and ITS sequences were reliable and adaptive for Acropora taxonomy at the species level and can be used as a DNA barcoding, but PaxC has great potential as a DNA barcoding.3) The mitochondrial markers were also difficult to distinguish the interspecific genetic relationship, which were fit for phylogenetic analyses at or above the genus level and can also separate the Pacific and Caribbean groups, but are not suitable for the judgment of interspecific relationship. The mitochondrial gene is suitable as the classification of a higher class and different geographical regions.4) Morphological and molecular studies showed that the genetic relationship between A. valida, A. selago and A. nasuta were close and hybridization may occur between the three.On the whole, the molecular markers showed variable levels of adaptation among different taxonomic category. The nuclear gene is suitable as a lower classification barcoding, and the mitochondrial gene is suitable as a higher class barcoding. Different molecular markers used for classification and morphological classification that present consistency in different levels.