MOLECULAR PHYLOGENETIC RELATIONSHIP OF EPINEPHELUS BASED ON SEQUENCES OF MTDNA CYTB

The sequences ( 402bp-of mtDNA Cyt b were sequenced for such seven endemic species of groupers as Epinephelus awoara, E.brunneus, E.coioides, E.longispinis, E.sexfasciatus, E.spilotoceps and E.tauvina in China.The mtDNA Cyt b sequences of other seven foreign species of groupers, e.g., E.aeneus, E.caninus, E.drummondhayi, E.haif ensis, E.labrif ormis, E.marginatus and E.multinotatus from GenBank were combined and analysed as ingroup, and Variola louti was used as outgroup.The two types of molecular phylogenetic trees were based on the sequences of 15 species with maximum parsimony method ( MP-and neighbor-joining method (NJ-respectively.The results were as follows: (1-As to base const itution of mtDNA Cyt b sequence ( 402bp-of 14 kinds of Epinephelus, the content of (A+ T-is 53.6%, higher than that of (G+ C-(46.4%).The transition/transversion rat io is 4.78 with no mutation saturat ion.( 2-The cluster relationships between E.awoara and E.sexfasciat, E.coioides and E.tauvina, E.longispinis and E.spilotoceps respectively are consistent with phenotypes in taxonomy.( 3-In the system tree, the species in AtlanticOcean associate closely with those in Pacific Ocean, which suggests that the Cyt b sequences of Epinephelus express strict conservation and may be the result of coordinate evolut ion.( 4-In wel-l bred mat ing or heredity management, mixing mating of Epinephelus of the same branch should be avoided.It is likely to be an effective way to mate the species of Atlantic Ocean with those of Pacific Ocean in order to improve the inheritance species.