横断山地区六叶龙胆复合群的遗传分化与种群动态历史  

Genetic divergence and demographic history of Gentiana hexaphylla Maximowicz ex Kusnezow complex(Gentianaceae)in Hengduan Mountains

作　　者：付鹏程 谭金舟 王宏宇 孙姗姗 Fu Peng-Cheng;Tan Jing-Zhou;Wang Hong-Yu;Sun Shan-Shan(College of Life Science,Luoyang Normal University,Luoyang,Henan 471934,China)

机构地区：[1]洛阳师范学院生命科学学院,河南洛阳471934

出　　处：《植物科学学报》2020年第3期390-399,共10页Plant Science Journal

基　　金：国家自然科学基金项目(31600296);河南省高等学校青年骨干教师培养计划。

摘　　要：以六叶龙胆(Gentiana hexaphylla Maximowicz ex Kusnezow)复合群的21个居群为材料,首先通过居群内关键形态性状的统计对复合群加以区分,随后以叶绿体片段trnS-trnG为分子标记,对其遗传分化与种群动态历史进行研究。结果显示:六叶龙胆复合群21个居群共鉴定出20个单倍型,居群平均单倍型多样性、核苷酸多样性和核苷酸多样性指数分别为0.444、0.00732和3.73,表现出较高的遗传多样性水平;居群间共享单倍型少,遗传变异主要发生在居群间(72.74%)。贝叶斯分析结果表明复合群内的遗传分化主要发生在近两百万年以内。歧点分布分析和中性检验结果均显示,复合群近期未经历明显的居群扩张。因此,六叶龙胆复合群的遗传分化可能是横断山地区第四纪环境与气候变化以及高山峡谷地貌的地理隔离两者共同作用的结果。The Hengduan Mountains are a global biodiversity center and hotspot of plant evolution research.Being endemic to the Hengduan Mountains,Gentiana hexaphylla Maximowicz ex Kusnezow shows continuous morphological characters with many of its closely related species.In this study,21 populations were sampled to distinguish the G.hexaphylla complex through key morphological characters at the population level,and to explore genetic divergence and demographic history based on one chloroplast fragment.The number of haplotypes,average haplotype diversity,nucleotide diversity,and genetic diversity index(Pi)were 0.444,0.00732,and 3.73,respectively,indicating high genetic diversity in the complex.Haplotypes were rarely shared among populations and most genetic variation occurred among populations(72.74%)rather than within populations(27.26%).Bayesian analysis indicated that genetic divergence in the complex occurred within the last two million years.Mismatch distribution and neutrality tests consistently showed that the G.hexaphylla complex has not experienced significant population expansion recently.In conclusion,genetic divergence within the G.hexaphylla complex has been shaped by climatic and environmental changes during the Quaternary as well as by geological isolation in the Hengduan Mountains.

关 键 词：六叶龙胆 复合群 遗传分化 种群历史 横断山地区 

分 类 号：Q347[生物学—遗传学]