基于线粒体COI基因的云南西花蓟马种群遗传多样性研究

Polulation genetic diversity of Frankliniella occidentalis in Yuannan based on mtDNA CO I gene

【背景和目的】西花蓟马传播的番茄斑萎病毒属病毒可侵染烟草,为揭示云南西花蓟马传播扩散趋势。【方法】以线粒体DNA(mitochondrial DNA,mtDNA)COI基因为分子标记,检测23个不同云南西花蓟马地理种群的遗传多样性、遗传分化、分子变异和种群动态。【结果】基于mtDNA COI基因分析,共检测到10种单倍型,总群体的单倍型多样度(Hd)较高,为0.60700;总群体遗传分化指数(Fst)和基因流(Nm)分别为0.48031和4.46,表明云南西花蓟马各地理种群间基因交流水平较高;单倍型中介网络图没有明显分支;种群间分子变异主要来自种群内部;总群体中性检验Taijima’s D达到极显著水平,Fu’s Fs达到显著水平,且错配分布曲线中,除主峰外其余峰不明显,说明云南西花蓟马种群近期或正经历明显的种群扩张。【结论】云南西花蓟马种群遗传多样性丰富,近期种群或正经历明显扩张,应积极监测并采取有效的防控措施,保障农业生产健康发展。

[Background]Frankliniella occidentalis is an important agricultural pest worldwide.Orthotospoviruses transmitted by F.occidentalis seriously affects tobacco production.This study aims to reveal the spreading trend of F.occidentalis in Yunnan.[Methods]The mtDNA CO I sequences of F.occidentalis populations,collected from 23 different geographical areas in Yunnan,were selected as molecular markers.Their population genetic diversity,genetic differentiation,molecular variation,and population dynamics were analyzed by using software MEGA-X,DnaSP 6.0,Arlequin 3.5,and Network 5.0 etc.[Results]A total of 10 types of haplotypes were detected when the mtDNA CO I gene was analyzed,and the haplotype diversity(Hd)of different geographic population was high at 0.60700.The total genetic fixations index(Fst)and total gene flow(Nm)were 0.48031 and 4.46,respectively,indicating a high level of gene communication among populations.The haplotype network of different geographical populations based on mtDNA CO I showed no obvious branches,and the analysis of molecular variance(AMOVA)of different populations showed that the molecular variation between populations mainly comes from within-population variation.The neutrality tests,Taijima's D and Fu's Fs,reached extremely significant and significant levels,respectively,in the total population.The peaks in the mismatch distribution curve were not obvious except for the main peak,indicating that the population of F.occidentalis in Yunnan has recently experienced or is undergoing population expansion.[Conclusion]The genetic diversity of F.occidentalis population in Yunnan is rich,which may be experiencing obvious population expansion recently.Therefore,efforts should be made to actively monitor and take effective prevention and control measures to ensure the healthy development of agricultural production..