Data from: Genetic diversity and evolutionary history of four closely related Aquilegia species revealed by ten nuclear gene fragments

Recently the genus Aquilegia is emerging as the new model system for plant development, ecology and evolution studies. Previous researches demonstrated that pollinator shift might drive the diversification of North American Aquilegia species and natural selection on the length of spur might play a crucial role. In this genus, A. ecalcarata is the only taxon which has lost spur and nectar on the petal. Previous phylogenetic result indicated that A. ecalcarata, A. yabeana, A. oxysepala var. kansuensis and A. rockii comprised a monophyletic group. However, the genetic diversity pattern of them remains unknown. Besides, little is known about the evolutionary relationship among the four species on population level. Here we carried out a population genetics study with 21 representative populations based on 10 single-copy nuclear gene fragments and found out: 1) A. yabeana conserved the highest genetic diversity (both πsil and θsil) while A. oxysepala var. kansuensis had the lowest level; 2) A. ecalcarata splitted into two groups with one population clustered with A. rockii and the rest five populations clustered with A. oxysepala var. kansuensis; 3) allele frequency spectrum showed an excess of low frequency alleles in all four species, implying that they may undergo the mutation-drift equilibrium. Our findings provide the first investigation of genetic diversity and evolutionary relationship in A. yabeana, A. oxysepala var. kansuensis, A. rockii, A. ecalcarata, and lay foundation for future evolutionary studies like speciation mediated by pollinators.

近年来，耧斗菜属（Aquilegia）正逐渐成为植物发育学、生态学与进化生物学研究的新兴模式系统。既往研究表明，传粉者转换可能推动了北美耧斗菜物种的分化，而针对花距长度的自然选择或许发挥了关键作用。在该属中，无距耧斗菜（A. ecalcarata）是唯一缺失花瓣距与花蜜的类群。此前的系统发育研究结果显示，无距耧斗菜（A. ecalcarata）、亚氏耧斗菜（A. yabeana）、尖萼耧斗菜甘肃变种（A. oxysepala var. kansuensis）以及秦岭耧斗菜（A. rockii）构成一个单系群。然而，这四个类群的遗传多样性格局仍未明确；此外，在种群水平上，这四个物种间的演化关系也鲜有研究。本研究基于10个单拷贝核基因片段，对21个代表性种群开展了群体遗传学分析，结果如下：1）亚氏耧斗菜（A. yabeana）的遗传多样性（包括沉默位点核苷酸多样性πsil与沉默位点θsil）最高，而尖萼耧斗菜甘肃变种（A. oxysepala var. kansuensis）的遗传多样性最低；2）无距耧斗菜（A. ecalcarata）可分为两个类群：其中一个种群与秦岭耧斗菜（A. rockii）聚为一支，其余五个种群则与尖萼耧斗菜甘肃变种聚为一支；3）所有四个物种的等位基因频率谱均呈现低频等位基因过量的特征，暗示它们可能处于突变-漂移平衡状态。本研究首次对亚氏耧斗菜、尖萼耧斗菜甘肃变种、秦岭耧斗菜以及无距耧斗菜的遗传多样性与演化关系开展了探究，为后续诸如传粉者介导的物种形成等进化生物学研究奠定了基础。