基于线粒体基因序列的广西柑橘木虱遗传多样性及种群结构分析

Genetic diversity and population structure analysis of Diaphorina citri Kuwayama in Guangxi based on mitochondrial gene sequences

【目的】研究广西柑橘木虱遗传多样性及种群结构,为制定柑橘木虱的防控措施提供理论基础。【方法】通过分析来自我国广东、贵州、云南、海南、广西以及越南太平和柬埔寨暹粒等地区的9个柑橘木虱线粒体基因组序列,确定并设计针对多态性位点的引物。利用获得的引物对采集自广西合浦、环江、富川、西林、永福和右江6个柑橘产区的柑橘木虱线粒体基因序列进行扩增和测序;使用DnaSP 6.12对测序序列进行多态性分析和单倍型多样性分析;采用最大似然法和贝叶斯法构建系统发育进化树;使用PopART绘制单倍型网络图以展示种群进化结构和关系。【结果】对来自我国和越南太平、柬埔寨暹粒的9个柑橘木虱线粒体基因组序列进行比对分析,共获得22个多态性位点,针对多态性位点区域序列设计引物并筛选获得5对有效引物,其中包括8个多态性位点。利用5对引物对采集自广西6个柑橘产区的18个柑橘木虱线粒体基因进行PCR扩增并测序,获得总长度2272 bp的线粒体基因序列,经分析发现广西柑橘木虱共包含6种单倍型,单倍型多样性为0.882、核苷酸多样性为0.00181。最大似然进化树、贝叶斯进化树和单倍型网络分析发现,广西西林柑橘木虱种群与云贵川等我国西南地区高海拔的柑橘木虱种群在遗传距离上较近,其他地区的柑橘木虱种群与我国南方和东南亚的种群更接近。【结论】广西柑橘木虱种群展现较高的单倍型多样性和较低的核苷酸多样性,表现明显的种群结构分化和多样性;广西柑橘木虱种群遗传分化受地理距离影响明显,二者存在相关性。

【Objective】To study the genetic diversity and population structure of Diaphorina citri Kuwayama in Guangxi,this study provided research foundation for the strategy of controlling D.citri.【Method】Mitochondrial genome sequences of D.citri from 9 regions,Guangdong,Guizhou,Yunnan,Hainan and Guangxi of China,Thai Binh of Vietnam and Siem Reap of Cambodia,were analyzed to identify and design primers for polymorphic sites.Amplification and sequencing on D.citri gene mitochondrial sequences from Hepu,Huanjiang,Fuchuan,Xilin,Yongfu and Youjiang in Guangxi were conducted.DnaSP 6.12 was used to analyze the polymorphism and haplotype diversity of the sequences;and phylogenetic trees were constructed using maximum likelihood method and Bayes method;haplotype network was generated using PopART software to depict the population genetic structure and relationships.【Result】The mitochondrial genome sequences of 9 D.citri samples from China,Thai Binh of Vietnam and Siem Reap of Cambodia were compared and analyzed,resulting in the identification of 22 polymorphic sites.Primers were designed for the regions surrounding these polymorphic sites,and 5 pairs of effective primers were selected,which included 8 polymorphic sites.Mitochondrial genes of 18 D.citri collected from 6 citrus producing areas in Guangxi were amplified and sequenced by PCR using 5 pairs of primers,resulting in a mitochondrial gene sequence with a total length of 2272 bp.Analysis showed that D.citri in Guangxi contained 6 haplotypes,the haplotype diversity was 0.882,with a nucleotide diversity of 0.00181.Maximum likelihood evolutionary tree,Bayesian evolutionary tree and haplotype network analysis showed that the genetic distance between Xilin D.citri population in Guangxi and D.citri populations at high altitude in southwestern China such as Yunnan,Guizhou and Sichuan was relatively close,while populations in other regions were more closely related to those in southern China and southeastern Asia.【Conclusion】D.citri populations in Guangxi exhibit high haplotype diversity and low nucleotide diversity,implying obvious differentiation and diversity of population structure.The genetic differentiation of D.citri population in Guangxi is affected by geographical distance,and there is correlation between the two.