Genetic diversity and evolutionary history of four closely related Aquilegia species revealed by 10 nuclear gene fragments  

作　　者：Lei Huang Fang-Dong Geng Jing-Jing Fan Cheng Xue Xiao-Yan Zhang Ju-qing Kang Jian-qiang Zhang Yi Ren 

机构地区：[1]College of Life Science, Shaanxi Normal University, Xi'an 710119, China

出　　处：《Journal of Systematics and Evolution》2018年第2期129-138,共10页植物分类学报（英文版）

基　　金：We thank Li Sun, Wei Zhai, and Xiao-Peng Chang for sample collection and other members of Ren＇s group for their technical assistance. We are grateful to Professor Hong-Zhi Kong （institute of Botany, CAS）for valuable comments on this study, and to Xiao-Hui Zhang and Xu-Mei Wang for valuable comments and smoothing the manuscript. This work wassupported by the National Natural Science Foundation of China （31700180）.

摘　　要：The genus Aquilegia is emerging as the new model system for plant development, ecology, and evolution studies. Previous research showed that pollinator shift might drive the diversification of North American Aquilegia species, and natural selection on the length of petal nectar spur might play a crucial role. In this genus, A. ecalcarata Maxim. is the only taxon that has lost nectar spurs. Previous phylogenetic results indicated that A. ecalcarata, A. yabeana Kitag., A. oxysepala var. kansuensis Bruhl., and A. rockii Munz comprised a monophyletic group. However, their pattern of genetic diversity remains unknown. In addition, little is known about the evolutionary relationship among the four species on the population level. We carried out a population genetics study with 21 representative populations based on lo single-copy nuclear gene fragments and found that： （i） A. yabeana conserved the highest genetic diversity （both πsil and θsil） and A. oxysepala var. kansuensis had the lowest level; （ii） A. ecalcarata split into two groups, with one population clustered with A. rockii and the other five populations clustered with A. oxysepala var. kansuensis; and （iii） the 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 relationships in A. yabeana, A. oxysepala var. kansuensis, A. rockii, and A. ecalcarata. They lay the foundation for future evolutionary studies, such as speciation mediated by pollinators.The genus Aquilegia is emerging as the new model system for plant development, ecology, and evolution studies. Previous research showed that pollinator shift might drive the diversification of North American Aquilegia species, and natural selection on the length of petal nectar spur might play a crucial role. In this genus, A. ecalcarata Maxim. is the only taxon that has lost nectar spurs. Previous phylogenetic results indicated that A. ecalcarata, A. yabeana Kitag., A. oxysepala var. kansuensis Bruhl., and A. rockii Munz comprised a monophyletic group. However, their pattern of genetic diversity remains unknown. In addition, little is known about the evolutionary relationship among the four species on the population level. We carried out a population genetics study with 21 representative populations based on lo single-copy nuclear gene fragments and found that： （i） A. yabeana conserved the highest genetic diversity （both πsil and θsil） and A. oxysepala var. kansuensis had the lowest level; （ii） A. ecalcarata split into two groups, with one population clustered with A. rockii and the other five populations clustered with A. oxysepala var. kansuensis; and （iii） the 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 relationships in A. yabeana, A. oxysepala var. kansuensis, A. rockii, and A. ecalcarata. They lay the foundation for future evolutionary studies, such as speciation mediated by pollinators.

关 键 词：Aquilegia ecalcarata A. oxysepala var. kansuensis A. rockii A. yabeana evolutionary history genetic diversity. 

分 类 号：Q987[生物学—遗传学] Q959.843[生物学—人类学]