| 摘要: |
| 扁圆吻鲴（Distoechodon compressus）是一种局域分布于我国福建、江西、台湾的小型经济鱼类，目前尚无其群体遗传学相关研究，此外扁圆吻鲴在鲴亚科（Xenocyprinae）鱼类中的分类地位也有争议。本研究基于线粒体Cyt b基因，对采自福建连城附近水域的三个扁圆吻鲴群体的遗传多样性、群体结构和历史动态进行分析。结果显示扁圆吻鲴的三个群体共检测到15个单倍型，整体单倍型多样性较高（0.554）而核苷酸多样性较低（0.001 42），三个群体中池塘养殖群体的单倍型多样性和核苷酸多样性均最高，分别为0.600和0.002 24；各群体间未检测到显著的遗传分化，且遗传距离均极低（小于0.002）；群体历史动态分析结果也未检测到明显的群体扩张或瓶颈效应等。此外，分别基于邻接法（neighbor-joining， NJ）、最大似然法（maximum likelihood， ML）和贝叶斯法（Bayesian inference， BI）对鲴亚科已报道的基因序列进行系统发育分析，结果显示似鲴属（Xenocyprioides）位于系统发育树基部；鲴属（Xenocypris）和圆吻鲴属（Distoechodon）并未各自形成单系，而是不同属的各物种互为并系；在圆吻鲴属内部，扁圆吻鲴和圆吻鲴无法通过Cyt b基因进行区分，因此未来仍需更多的分子标记以支持鲴亚科的系统发育关系。本研究的开展有助于了解扁圆吻鲴的遗传多样性现状和群体结构，为资源保护管理提供了基础资料，同时也为鲴亚科的系统发育和进化历史提供了重要参考。 |
| 关键词: 扁圆吻鲴 线粒体细胞色素b基因 遗传多样性 鲴亚科 系统发育关系 |
| DOI：10.14188/j.ajsh.2022.05.004 |
| 分类号:Q958.8 |
| 基金项目:福建省自然科学基金面上项目（2022J011136）；福建省教育厅中青年教师教育科研项目（JAT200445） |
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| Genetic diversity of Distoechodon compressus and discussion of its phylogenetic relationships in subfamily Xenocyprinae |
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ZHANG Zhi1, LI Jiming2, ZHANG Xiaodong3, LIN Bingming3, CHEN Jianming1
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1.Fujian Key Laboratory on Conservation and Sustainable Utilization of Marine Biodiversity， Fuzhou Institute of Oceanography， Minjiang University， Fuzhou 350108， Fujian， China;2.Liancheng Jiming Fish Farming Company， Longyan 366202， Fujian， China;3.Longyan Fisheries Technology Extension Center， Longyan 364000， Fujian， China
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| Abstract: |
| Distoechodon compressus is a small economic fish distributed locally in Fujian， Jiangxi and Taiwan in China. At present， there is no research on its population genetics. In addition， its taxonomic status in subfamily Xenocyprinae is controversial. Based on mitochondrial DNA Cyt b gene sequences， the present study investigated the genetic diversity， population structure and population demography of three populations of Distoechodon compressus collected from waters near Liancheng County， Fujian Province. The results showed that 15 haplotypes were identified for 90 individuals with relatively high haplotype diversity （Hd=0.554） and low nucleotide diversity （Pi=0.001 42）. Among the three populations， CT population had the highest Hd and Pi （0.600 and 0.002 24， respectively）. Genetic differentiation indexes of pairwise comparison of different populations were very low（<0.002）， indicating no genetic differentiation among populations. No significant expansion or bottleneck effect was detected by population demography analysis. Furthermore， phylogenetic analysis of Cyt b sequences within subfamily Xenocyprinae illustrates that genus Xenocyprioides is located at the base of phylogenetic tree. Xenocypris and Distoechodon do not form their own monophyly， but species of different genera are parallel to each other. Within genus Distoechodon， D. compressus and D. tumirostris cannot be distinguished by Cyt b gene， so that more molecular markers are needed to analyze phylogenetic relationships in the future. This study is helpful to understand the status of genetic diversity and population structure for this locally distributed fish， and to provide basic information for resource conservation and management， as well as reference for phylogenetic and evolutionary history of subfamily Xenocyprinae. |
| Key words: Distoechodon compressus mitochondrial Cyt b gene genetic diversity subfamily Xenocyprinae phylogenetic relationship |
