[Molecular phylogeny of some species of the acridoidea based on 16S rDNA].

Based on the 16S rDNA of 8 species (belonging to 8 families of Acridoidea) from China and keyed to 8 relative species of Orthoptera from GenBank, the homologus sequences were compared. The used frequency of nucleotide was calculated and the molecular phylogenetic tree constructed by MEGA microsoft. In the 480 bp fragment of mitochondial 16S rDNA, A + T was about 70.7% and G + C only 29.3%. The sequence data revealed considerable variation in 188 nucleotide sites among the analyzed individuals from 8 different families. The variation rate of transversion was larger than or approach to transition. The results showed that the ranges of the 16S rDNA nucleotide divergence within species, among species of a genus, among genera of a family, and among the same family and suborder were 1.5%, 3.5%-3.6%, 4.8%-15.8% and 15.2%-25.6%, respectively. The members of the same genus and family were grouped together. The phylogenetic relationships of 8 families were Pyrgomorphidae-->Chrotogonidae-->Pamphagidae-->Oedipodidae-->Acrididae--> Arcypteridae-->Gomphoceridae-->Catantopidae. Pyrgomorphidae had closer relationships with Chrotogonidae as well as being the most ancestral group. Arcypteridae and Gomphoceridae were the sister groups and had closer relationships with most evolutionary Catantopidae. Tridactylidae was divided firstly as a suborder, which differs from the recent taxonomy distinctly. Haglidae (Tettigonoidea) and Gryllidae were grouped into suborder Ensifera, Tetrigidae and 8 families of Acridoidea were grouped into suborder Caelifera, as same as recent taxonomy.