【摘要】 将自测的我国直翅目蝗总科8科14种的rDNA-ITS2核酸序列片段进行同源性比较,计算核苷酸使用频率,并构建分子系统树。在获得的325 bp的序列中,A+T平均含量37.2%,G+C为平均含量62.8%,颠换取代(transversion)的速率大于转换取代(transition)的速率,其中249核苷酸位点存在变异。以蟋蟀总科Grylloidea的Acheta domesticus为外群构建分子系统树,结果表明:蝗总科8科的起源关系为:瘤锥蝗科→锥头蝗科→癞蝗科→网翅蝗科和斑翅蝗科→槌角蝗科→剑角蝗科→斑腿蝗科;锥头蝗科与瘤锥蝗科关系较近,并与癞蝗科形成姐妹群,是蝗总科内最原始的类群;斑翅蝗科和网翅蝗科互为姐妹群,与槌角蝗科关系较近,斑腿蝗科为最进化类群,同现用的分类系统。更多还原

【Abstract】 Based on the rDNA- ITS2 of 14 species( belonging to 8 families of Acridoidea) from China,the homologus sequences were compared. The used frequency of nucleotide was calculated and the molecular phylogenetic tree was constructed by MEGA microsoft. In the 325 bp fragment of rDNA- ITS2,G + C was about 62. 8% and A + T only 37. 2%. The variation rate of transversion was larger than transition. Phylogeny was reconstructed using Acheta domesticus( Grylloidea) as outgroups,the phylogenetic relationships of 8 families were Chrotogonidae → Pyrgomorphidae → Pamphagidae → Arcypteridae, Oedipodidae→Gomphoceridae→Acrididae →Catantopidae. Pyrgomorphidae had closer relationships with Chrotogonidae and Pamphagidae were the sister groups as well as being the most ancestral group. Arcypteridae and Oedipodidae were the sister groups and had closer relationships with Gomphoceridae, Catantopidae was the most evolutionary group,as same as recent taxonomy.更多还原