Mechanism of rapid speciation and the role of environmental factors: A
case study of Aquilegia viridiflora
Clarifying the role of key genes in the early stage of speciation is
critical to understand the origin and evolution of species. Aquilegia
viridiflora, in the early stage of speciation, has a wide distribution
range, and shows obvious phenotypic variation among its different
populations. Here, we analyzed the adaptive evolution mechanism of
phenotypic differences in the early stages of speciation using the
phenotypes, genomes, and transcriptomes of different populations of A.
viridiflora. Our results indicated that A. viridiflora originated in
northwestern China, and the environmental changes caused by the uplift
of the northeastern Qinghai–Tibet Plateau in the late Miocene may have
caused its differentiation. Within its distribution range, flower size
was significantly negatively correlated with the inflorescence number
and leaf area. Aqcoe5G459400 expression was reduced in environments with
large temperature differences between day and night, possibly resulting
in longer spurs and promoting the formation of reproductive isolation.
Additionally, the cytochrome P450 (CYP 450) superfamily may have driven
species differentiation in the early stage of speciation. Our study
reveals the genetic basis of the adaptive evolution of the phenotype in
the early stage of speciation and provides new evidence of the rapid
evolution of angiosperms.