中国南方茶棍蓟马地理种群遗传分化分析

Genetic differentiation analysis of geographical populations of Dendrothrips minowai(Thysanoptera:Thripidae)in South China

【目的】基于mtDNA COI和COⅡ的联合序列,探讨中国南方茶棍蓟马Dendrothrips minowai地理种群的遗传多样性与遗传分化。【方法】利用MEGA 6.0,DnaSP 5.10和Arlequin 3.5.2.2等软件对中国南方茶棍蓟马8个地理种群遗传多样性、遗传分化、基因流、分子变异及地理距离与遗传距离的相关性进行分析,并推断群体演化历史。【结果】茶棍蓟马mtDNA COI和COⅡ序列均具有明显的AT偏好性,COI和COⅡ联合序列的长度为1146 bp,共有22个单倍型。中国南方茶棍蓟马总群体遗传多样性较高,表现出高单倍型多样性(Hd=0.924)和低核苷酸多样性(π=0.00600)。8个地理种群总群体的遗传分化程度高(F_(ST)=0.84830),基因交流水平低(Nm=0.040),群体可能由于遗传漂变而发生明显分化。AMOVA分析显示,茶棍蓟马种群的遗传变异主要来自组间种群(F_(CT)=0.84922);Mantel检测显示地理距离与遗传距离存在显著的正相关(r=0.5029,P<0.01)。中性检验结果表明,除云南两个地理种群外的其他地理种群近期可能经历了种群扩张。【结论】中国南方茶棍蓟马地理种群遗传多样性较高,具有明显的遗传分化,基因交流较少;地理距离可能是影响茶棍蓟马地理种群遗传分化的主要因素之一。

【Aim】The objective of this study is to investigate the genetic diversity and genetic differentiation of geographical populations of the stick tea thrip,Dendrothrips minowai,in South China based on the combined sequence of mtDNA COⅠand COⅡ.【Methods】The genetic diversity,genetic differentiation,gene flow,analysis of molecular variance and correlations between geographical distance and genetic distance of eight geographical populations of D.minowai in South China were analyzed by using software MEGA 6.0,DnaSP 5.10,Arlequin 3.5.2.2,etc.,and their demographic history was deduced.【Results】Both the mtDNA COⅠand COⅡsequences of D.minowai have obvious AT bias,and the combined sequence of COⅠand COⅡis 1146 bp in length with 22 haplotypes.The total population of D.minowai in South China had a high level of genetic diversity,high haplotype diversity(Hd=0.924)and low nucleotide diversity(π=0.00600).The total population of the eight geographical populations had a high degree of genetic differentiation(F_(ST)=0.84830)and low level of gene communication(Nm=0.040).Significant differentiation might have occurred among different geographical populations due to genetic drift.AMOVA analysis showed that the genetic variation mainly came from the populations among groups(F_(CT)=0.84922).Mantel test indicated that the geographical distance was significantly positively correlated with the genetic distance(r=0.5029,P<0.01).Neutrality test results revealed that the geographical populations of D.minowai except the two geographical populations in Yunnan Province have experienced population expansion recently.【Conclusion】Geographical populations of D.minowai in South China have a high level of genetic diversity,a high degree of genetic differentiation and a low level of gene communication.Geographical distance might be one of the key factors affecting genetic differentiation among geographical populations of D.minowai.