基于线粒体16S rRNA基因的舟山群岛碧蛾蜡蝉种群遗传多样性分析

【目的】揭示岛屿隔离效应对舟山群岛及邻近大陆碧蛾蜡蝉Geisha distinctissima种群遗传多样性的影响。【方法】依据本研究获取的舟山群岛(11个岛屿)及邻近大陆15个种群共247头碧蛾蜡蝉样本的16S rRNA基因序列,对该地区种群进行遗传多样性评估;采用贝叶斯推断法构建系统发育树并绘制单倍型网络图,以解析种群间的遗传结构;通过中性检验、错配分布分析和贝叶斯天空线(Bayesian skyline plot, BSP)分析,探讨该地区碧蛾蜡蝉的种群历史动态。【结果】贝叶斯系统树及单倍型网络图均没有解析出舟山群岛碧蛾蜡蝉种群明显的遗传结构。且分子方差分析发现,遗传变异主要集中在种群内部(种群内变异占68.26%),种群间没有明显的遗传分化,显示了该地区碧蛾蜡蝉种群遗传多样性的均质化。不同种群间的单倍型多态性和核苷酸多态性与大陆-岛屿距离及岛屿隔离时间不相关。中性检验分析检测到Tajima’s D和Fu’s Fs均呈显著的负值,且错配分布分析呈现出典型的单峰,表明该地区碧蛾蜡蝉种群发生了近期的种群扩张事件。BSP分析表明,这种扩张事件发生在大约0.5～3.5千年前。【结论】岛屿隔离效应可能不足以驱使舟山群岛及邻近大陆的碧蛾蜡蝉种群遗传多样性产生明显的差异。

Genetic diversity analysis of Geisha distinctissima (Fulgoroidea: Flatidae) in the ZhoushanArchipelago based on mitochondrial 16S rRNA gene

【Aim】 This study aims to reveal the impact of island isolation on the geneticdiversity of Geisha distinctissima inhabiting in the Zhoushan Archipelago in East China. 【Methods】 Based on 16S rRNA gene fragments of 247 individuals from 15 populations of G.distinctissima in 11 islands and adjacent mainland obtained in this study, the populationgenetic diversity of G. distinctissima in this region was assessed. The phylogeneticanalysis was conducted using Bayesian inference method and the haplotype network wasconstructed to resolve genetic structures among G. distinctissima populations. Thedemographic history of G. distinctissima populations was also evaluated by neutrality test,mismatch distribution analysis and Bayesian skyline plots (BSP). 【Results】 Both Bayesianphylogenetic analysis and haplotype network showed that the G. distinctissima populationsin the Zhoushan Archipelago did not develop distinct genetic structure. Moreover, themolecular analysis of variance (AMOVA) showed that genetic differentiation mainly occurredwithin population (68.26%), suggesting that G. distinctissima populations of this regionare homogeneous in genetic diversity. No correlation was found between the haplotype andnucleotide diversity and the isolated time and distance of islands. In addition, theneutral test showed that both Tajima’s D and Fu’s Fs exhibited prominent negative values,and there was a single peak in mismatch distribution analysis with canonical unimodalformat, suggesting that G. distinctissima populations in the Zhoushan Archipelago maysuffer from population expansion events. The BSP analysis showed that the expansion eventsoccurred between 0.5-3.5 thousand years ago (kya). 【Conclusion】 Island isolation mighthave not exerted visible impacts on the divergence of genetic diversity among G.distinctissima populations in the Zhoushan Archipelago and adjacent mainland.