不同色斑型异色瓢虫COⅠ和COⅡ基因序列系统进化分析

利用线粒体COⅠ和COⅡ基因序列分析法,研究13种色斑型异色瓢虫Harmonia axyridis Pallas的系统分化,计算核苷酸的使用频率,并构建分子系统树,以便更好地探索异色瓢虫色斑变异的规律。结果表明,在用于分析的COⅠ基因和COⅡ基因的序列中,共有31个变异位点,29个简约信息位点,A+T平均约占71.2%,大部分碱基改变为颠换。13种不同色斑型异色瓢虫的遗传距离为0.0021～0.0328,平均相似系数为0.0193。分别采用邻接法(NJ)、最大简约法(MP)、最小进化法(ME)构建系统发育树。分子系统树显示:各类群间遗传分化很小,鞘翅颜色相同的瓢虫均已较高的置信值聚在一起;双月斑变型和显明变种亲缘关系最近,重名变种为原始类群,分化较早,与其它12种不同色斑异色瓢虫亲缘关系较远。

Phylogenetic analysis of COⅠ and COⅡ gene sequences of different splash types of Harmonia axyridis

Phylogenetic analysis of 13 species splash types of Harmonia axyridis Pallas was conducted based on mitochondrial CO Ⅰ and CO Ⅱ DNA sequences. The frequency of nucleotide usage was calculated and the molecular phylogenetic tree was constructed in order to explore the regular pattern of the variation of H. axyridis splash types. The results revealed that there were 31 variable sites and 29 parsimony-information sites in CO Ⅰ and CO Ⅱ gene sequence fragments, and mean A + T content was about 71.2%, most of which were transformed through transversion. By using Neighbor-Joining (NJ) , Maximum Parsimony (MP) and Minimum Evolution (ME) methods, we constructed the molecular phylogeny. The genetic distance among different splash types of H .axyridis was 0.0021 to 0.0328. The average genetic distance was 0.0193. The molecular phylogenetic tree suggested that the members with the same elytron color were grouped together with high bootstrap confidence values, showing low diversity among the populations. H. axyridis ab. luna ta Hem and H. axyridis var. spectabilis Fald were most closely related. H. axyridis var. axyridis Pallas was a primordial population of coccinellidae, which was differentiated earlier than the other populations.