菱角萤叶甲不同地理种群及近缘种rDNA-ITS1基因序列初步分析

通过对我国菱角萤叶甲Galerucella birmanica Jacoby 6个地理种群和褐背小萤叶甲Galerucella grisescens Joannis扬州种群的核糖体DNA第1内转录间隔区（rDNA-ITS1）的测序,并调用GenBank中该属其它4种昆虫的同源序列,运用软件DNAStar的MegAlign程序对小萤叶甲属种间、同种不同地理种群之间的ITS1序列的遗传分歧及相似性进行了分析,运用Mega3.0软件建立系统发育关系.序列分析结果表明,rDNA-ITS1基因在小萤叶甲属昆虫中进化速度较快,种下具有一定的差异,种间差异明显.该基因适合小萤叶甲属种间和种下的分类鉴定研究.进化树显示,菱角萤叶甲泰安种群和扬州种群形成一个分支,益阳种群和新余种群形成一个分支,苏州种群和上海青浦种群形成一个分支,这一现象说明6个地理种群的菱角萤叶甲分化与寄主和地理距离之间具有较高的相关性.

POPULATION GENETIC STRUCTURE OF WATER CHESTNUT BEETLE AND RELATIVE SPECHES BASED ON MOLECULAR EVIDENCE FROM rDNA-ITS1

The internal transcribed spacer 1 (ITS1) of ribosomal DNA of Galerucella grisescens and 6 geo-populations of Galerucella birmanica are sequenced, at the same time, the sequences of G.lineola, G.calmariensis, G.nymphaeae and G.pusilla are transferred from GenBank. The identity and variation of ITS1 sequences between species, and populations within an individual were then analyzed by biosoftware DNAStar and the phylogenetic relationships are established by Mega 3.0. The results showed that the ITS1 identity between the genera Galerucella and outgroup was very low, whereas the ITS1 sequences between infraspecies and interspecies of Galerucella were moderately conserved. These results suggested that ITS1 is a reasonable target region for molecular identification of Galerucella spp. and infraspecies; Contemporary we found that the polarization of 6 geo-populations of Galerucella birmanica had high relativity with host and geography distance, formed 3 embranchment.