Abstract: In order to systematic study grasshoppers in Inner Mongolia on a molecular level, the rDNA-ITS2 sequences of 120 individuals from 10 common grassland species of Inner Mongolia were amplified and a 180~197 bp ITS2 sequence was obtained by comparing with known grasshopper's ITS2 in Genbank. The obtained ITS2 sequences were aligned using MEGA 4.0 and the ITS2 sequences of Oedaleus asiaticus populations from 15 different areas were analyzed. The grasshopper's ITS2 sequence showed GC preference. The populations of O. asiaticus from 15 different areas had so little differences that only two individuals varied. The number of variation sites was 11 which were all base substitutions and made up 5.67% of detected sequences. Clustering results of 15 populations showed that 13 populations was firstly clustered with a population from Siziwang Banner, and finally with a population from Bai Banner. These results indicated that ITS2 was a highly conserved sequence and not suitable for research on genetic differentiation below grasshopper specie level. Genetic distances of grasshopper species in the same genus were 0.0000, indicating that ITS2 sequence could not be used for species identification in the same genus. Gomphoceridae was firstly clustered with Arcypteridae, secondly with Oedipodidae and finally with Catantopidae, showing evolutionary relationships among different families.

Key words: Grasshopper, rDNA-ITS2, Genetic relationship

摘要： 为从分子水平对内蒙古草原蝗虫进行系统性研究,对内蒙古地区常见的10种草原蝗虫的120个个体的rDNA-ITS2序列进行扩增,通过与GenBank中已知蝗虫的ITS2对比得到180~197 bp的ITS2序列。使用MEGA 4.0软件对得到的ITS2序列进行对比,并对15个不同地点的亚洲小车蝗(Oedaleus asiaticus)种群进行比较分析。结果表明:10种蝗虫的ITS2序列的碱基组成显示出对鸟嘌呤(G)和胞嘧啶(C)的偏好性;15个地点的亚洲小车蝗种群之间差异小,仅有2个个体产生变异,共有11个变异位点,均为碱基的替换,占所测序列的5.67%。15个种群聚类结果显示,13个种群为一支先与四子王旗种群聚在一起,再与正镶白旗种群相聚;说明ITS2序列在蝗虫种下的遗传分化上为高度保守的序列,不适用于蝗虫种下遗传分化的研究。同属蝗虫之间的遗传距离为0.0000,说明ITS2序列也不能区分同一属蝗虫。槌角蝗科先与网翅蝗科聚类再与斑翅蝗科相聚,最后与斑腿蝗科相聚,反映了各科亲缘关系的远近。

关键词: 蝗虫, rDNA-ITS2, 亲缘关系