基于COI及28SrDNA序列分析的扶桑绵粉蚧地理种群的遗传分化研究

Genetic Differentiation Among Different Geographic Populations of Phenacoccus solenopsis Based on Sequences of COI and 28S rDNA

扶桑绵粉蚧(Phenacoccus solenopsis Tinsley)为危害棉花等经济作物安全生产的一种重要检疫性害虫。本研究分析了我国扶桑绵粉蚧6个地理种群(江苏、安徽、湖北、浙江、广东、广西)线粒体COI及核基因28S rDNA序列,结合中国海南、印度、巴基斯坦、美国地理种群的数据,分析了其可能的遗传分支。结果表明:扶桑绵粉蚧COI有7个单倍型,地理种群间显示出较小的遗传差异;28S rDNA序列在已测的中国六个地理种群中的结果高度保守,从核基因角度佐证了该种可能尚未出现种间分化。基于网络关系进化图、系统进化树分析得出扶桑绵粉蚧存在两个隐存谱系:((中国+印度+巴基斯坦)+美国加州)支系和美国佛罗里达支系;其中安徽及江苏种群应与入侵印度及巴基斯坦的支系为同一遗传支系。该研究结果可为探寻我国扶桑绵粉蚧的遗传进化和可能入侵途径提供参考。

Phenacoccus solenopsis Tinsley is one of the most important invasive pests that seriously damage cotton and other eco- nomic crops. In this study, the COI and 28S rDNA genes of P. solenopsis from Jiangsu, Anhui, Hubei, Zhejiang, Guangdong, and Guangxi provinces were sequenced and possible evolutionary lineages analyzed by combination with known COI sequences of P. solenopsis from other places （e.g., Hainan Province, India, Pakistan, and the United States）. The results showed there are seven haplotypes among these sequences of COI gene, which showed small genetic differences. The 28S rDNA gene was conserved a- mong the different geographic populations ofP. solenopsis in China, indicating that the genetic differentiation of these individuals has not reached interspecific differentiation based on nuclear genes. Two distinct evolutionary lineages appeared to exist in P. solenopsis based on the Median-Jointing network and phylogenetic tree. One clade includes P. solenopsis from China, India, Pak- istan, and California in the United States, while the other clade consists of P. solenopsis from Florida, USA. We also confirmed the evolutionary lineages of P. solenopsis in Jiangsu and Anhui provinces, which may suggest that they belong to the evolutionary lin- eages of India and Pakistan. This research could provide a reference for the genetic evolution and invasive route ofP. solenopsis.