中国水青冈属植物分类及分布区界定的分子证据  

Species delimitation and distribution of Fagus in China based on genomic sequence variation

作　　者：梁钰[1] 杨晓溪 张晓雅 王蔼英 张大勇[1] 廖万金 LIANG Yu;YANG XiaoXi;ZHANG XiaoYa;WANG AiYing;ZHANG DaYong;LIAO WanJin(MOE Key Laboratory for Biodiversity Science and Ecological Engineering,State Key Laboratory of Earth Surface Processes and Resource Ecology,College of Life Sciences,Beijing Normal University,Beijing 100875,China)

机构地区：[1]北京师范大学生命科学学院,地表过程与资源生态国家重点实验室,生物多样性与生态工程教育部重点实验室,北京100875

出　　处：《中国科学：生命科学》2022年第8期1292-1300,共9页Scientia Sinica(Vitae)

基　　金：科技部重点研发计划(批准号:2017YFA0605100);地表过程与资源生态国家重点实验室自主课题(批准号:2022-TS-04)资助。

摘　　要：物种分类地位和分布区的准确界定是保护生物学和生物多样性科学的研究基础.水青冈属(Fagus)植物是北半球落叶阔叶林重要树种,在我国具有较高的物种多样性.然而,水青冈属的属下分类界定仍不清晰,一些类群的归并问题有待商榷,缺乏遗传数据支持,导致物种分布的界限也不明确,妨碍对其进行有效保护.本研究使用水青冈属141个个体的重测序数据,进行了遗传分组分析,比较了几对姐妹类群间的遗传分化,讨论水青冈部分类群的归属问题,并计算了每个物种的遗传多样性(π).结果显示,巴山水青冈(F.pashanica)应作为一个独立物种,而不是台湾水青冈(F.hayatae)的亚种,分子证据支持曾被鉴定为浙江水青冈(F.hayatae subsp.zhejiangensis)的种群和四川省平武地区分布的疑似平武水青冈(F.chienii)种群均很有可能是巴山水青冈.天台水青冈(F.tientaiensis)可能是长柄水青冈(F.longipetiolata)的一个地理种群.根据更新的物种界定,台湾水青冈仅分布于我国台湾岛北部,巴山水青冈则呈带状间断分布于中国大陆几个隔离的山区.水青冈属植物遗传多样性均不低(π:0.00209~0.00371),这表明巴山水青冈等物种片段化的小种群可能是相对近期形成的.建议提升巴山水青冈、台湾水青冈和米心水青冈的保护等级,并关注片段化种群可能带来的遗传后果.Species delimitation is the foundation of biological conservation and biodiversity studies.The genus Fagus is a keystone resource in northern Hemisphere forests.China has the highest diversity of Fagus worldwide.However,species delimitation in the genus Fagus remains unclear and needs to be supported by genetic data.In this study,we sequenced whole genomes of 141 Fagus individuals and estimated their genetic structure and differentiation.With the newly revised molecular phylogeny of Fagus,we updated the distribution of five extant Fagus species in China and calculated the genetic diversity of Fagus species.Our results showed that F.pashanica is a separate species rather than a subspecies of F.hayatae.Moreover,F.chienii and F.hayatae subsp.zhejiangensis belong to F.pashanica,and F.tientaiensis belongs to F.longipetiolata.Consequently,F.hayatae only occurs in the northern part of Taiwan Island of China,whereas F.pashanica is discontinuously distributed in the mainland of China.All Fagus species had a relatively high genetic diversity(π:0.00209–0.00371),which suggests that small fragmented populations of the endangered Fagus arose recently.In conclusion,our results suggest that we should pay more attention to the protection of F.pashanica,F.hayatae,and F.engleriana,and evaluate the possible genetic consequences of fragmented populations.

关 键 词：水青冈属 遗传分化 遗传多样性 物种分类界定 物种保护 

分 类 号：Q949[生物学—植物学]