摘要
青藏高原是全球生物多样性中心之一,是研究物种形成和适应性进化的热点地区。龙胆属小龙胆组(Gentiana section Chondrophyllae s.l.)占整个龙胆属物种数目的近一半,以青藏高原为分化中心,但组内物种的遗传分化及其影响因素并不清楚。该研究以小龙胆组青藏高原特有植物——钻叶龙胆(G.haynaldii Kanitz)为研究对象,基于不同遗传方式的分子标记,通过种群遗传结构、遗传分化、种群动态历史和物种分布模型等分析,探讨其在青藏高原的分化历史。结果表明:(1)钻叶龙胆具有高的遗传多样性,种内遗传分化程度很高(叶绿体FST=0.532;ITS FST=0.511)。(2)钻叶龙胆种内的遗传分化主要发生在第四纪冰期以来,表明第四纪气候波动是钻叶龙胆分化的主要外部因素。(3)种群动态历史分析中,钻叶龙胆种群大小发生过扩张;物种分布模型分析表明,钻叶龙胆的分布区域在近期比较稳定,未发生明显扩张或收缩。该研究结果为龙胆属及青藏高原植物类群的物种分化和适应性研究提供了参考。
The Qinghai-Tibetan Plateau(QTP)is one of the global biodiversity hotspots and renowned for its high level of endemics.Numerous studies have explored the genetic differentiation and evolutionary history of plants in this region,but the large number of Gentiana endemics have been overlooked.Focusing on an annual Gentiana species(G.haynaldii Kanitz)in the QTP,we assessed their genetic structure,divergence and demographic history based on plastid and nuclear DNA sequences in this study.The results showed that:(1)relatively high level of genetic diversity and differentiation was observed in G.haynaldii(cpDNA,FST=0.532;ITS,FST=0.511).Genetic variance nearly equally occurred among populations or within population.(2)Demographic analyses showed signatures of recent population expansion in G.haynaldii.Species distribution modelling showed stable potential range except slight range expansion from the mid-Holocene to the present day.(3)Divergence time estimates suggested that the onset of intraspecific diversification generally fell into the Late Pliocene and the Early Pleistocene.The results indicated that the intraspecific divergence in G.haynaldii should be driven by geographical isolation and range fragmentation in glaciations rather than orogeny.This study provides insights into genetic differentiation and evolutionary history of the species-rich Gentiana as well as alpine plants in the QTP.
作者
付鹏程
刘玉玉
史明艳
FU Pengcheng;LIU Yuyu;SHI Mingyan(School of Life Science, Luoyang Normal University, Luoyang, Henan 471934, China)
出处
《西北植物学报》
CAS
CSCD
北大核心
2021年第8期1294-1301,共8页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家自然科学基金(31600296)。
关键词
钻叶龙胆
遗传分化
种群动态历史
物种分布模型
青藏高原
Gentiana haynaldii
genetic divergence
demographic history
species distribution model
Qinghai-Tibetan Plateau
作者简介
付鹏程(1988-),男,博士,副教授,主要从事植物进化研究,E-mail:fupengc@sina.com;通信作者:史明艳,博士,教授,主要从事生物资源保护研究,E-mail:smy2003@sina.com。
