Molecular Phylogenetic Analysis Of Acridoidea And Acrididae Based On Mitochondrial DNA Sequences

Grasshoppers (Orthoptera: Caelifera: Acridoidea), distribute widely on the world,and most of them are corp, forest and grassland pests. The classification of Acridoideais always controversial and has been a hot research issue of Orthoptera. Thesuperfamily usually is divided into 9 families by Chinese scholars (8 of them has beenfound in China) but this system is some dramatically different from that used byforeign researchers. In order to improve the taxonomic system of Acridoidea, it isnecessary to study the phylogeny of all families of it using molecular markers. Thepresent thesis, which focuses on the monophyly of Acrididae sensu Xia, is apreliminary try on this issue.Firstly, using fragments of 12S rDNA and Cyt b gene, we studied the phylogenetic relationships among 12 species of 8 families of Acridoidea. The alignment length of the fragments was 804 bp after excluded the positions without homology, including 437 variable sites and 256 parsimony informative sites. Phylogenies were reconstructed by using Formosatettix guangxiensis Zheng et Jiang as outgroup under unweighted NJ, MP, ML methods. We can deduce the phylogenetic relationships among those families: Pyrgomorphidae and Chrotogonidae → Oedipodidae → Cantantopidae → Pamphagidae → Arcypteridae → Acrididae and Gomphoceridae, which was a little different from previous morphological or molecular results.Secondly, we explored the phylogeny of Acrididae. In Xia's system, the family Acrididae has long been recognized as a natural, monophyletic group, which contain six subfamilies in China. However, there has been much dispute over its monophyly. To investigate its monophyly and phylogenetic relationships among six genera Carsula, Phlaeoba, Mongolotettix, Gelastorhinus, Acrida, and Gonista within this family, we sequenced 450 bp fragments of 16S rRNA gene sequences of 14 recognized species and downloaded the sequences of grasshopper Acrida turrita and two Tetrigidae species from GenBank. Phylogenetic trees were reconstructed with maximum parsimony, neighbor-joining, and maximum likelihood using the Tetrigidae species as outgroup. The monophyly of Acrididae was not supported in all...