The identification and understanding of cryptic intraspecific evolutionary units(lineages) are crucial for planning effective conservation strategies aimed at preserving genetic diversity in endangered species.However...The identification and understanding of cryptic intraspecific evolutionary units(lineages) are crucial for planning effective conservation strategies aimed at preserving genetic diversity in endangered species.However, the factors driving the evolution and maintenance of these intraspecific lineages in most endangered species remain poorly understood. In this study, we conducted resequencing of 77 individuals from 22 natural populations of Davidia involucrata, a “living fossil” dove tree endemic to central and southwest China. Our analysis revealed the presence of three distinct local lineages within this endangered species, which emerged approximately 3.09 and 0.32 million years ago. These divergence events align well with the geographic and climatic oscillations that occurred across the distributional range.Additionally, we observed frequent hybridization events between the three lineages, resulting in the formation of hybrid populations in their adjacent as well as disjunct regions. These hybridizations likely arose from climate-driven population expansion and/or long-distance gene flow. Furthermore, we identified numerous environment-correlated gene variants across the total and many other genes that exhibited signals of positive evolution during the maintenance of two major local lineages. Our findings shed light on the highly dynamic evolution underlying the remarkably similar phenotype of this endangered species. Importantly, these results not only provide guidance for the development of conservation plans but also enhance our understanding of evolutionary past for this and other endangered species with similar histories.展开更多
The phylogenetic position of the monotypic woody Parapteropyrum(Polygonaceae)remains controversial.Parapteropyrum has been thought to be closely related to the woody genera of the tribe Atraphaxideae,although some evi...The phylogenetic position of the monotypic woody Parapteropyrum(Polygonaceae)remains controversial.Parapteropyrum has been thought to be closely related to the woody genera of the tribe Atraphaxideae,although some evidence indicates that it nests within the herbal buckwheat genus Fagopyrum of tribe Polygoneae.In this study,we used plastome data to determine the phylogenetic position of Parapteropyrum(Fagopyrum)tibeticum.Different reference species were used to assemble plastomes of three species currently placed in the tribe Ataphaxideae:Parapteropyrum(Fagopyrum)tibeticum,Atraphaxis bracteata and Calligonum ebinuricum.Once assembled,plastomes were characterized and compared to plastomes of 12 species across the family Polygonaceae.Phylogenetic analyses of Polygonaceae were performed using whole plastome,all plastome genes,and single-copy genes.Plastomes assembled using different reference plastomes did not differ;however,annotations showed small variation.Plastomes of Parapteropyrum(Fagopyrum)tibeticum,A.bracteata and C.ebinuricum have the typical quadripartite structure with lengths between 159,265 bp and 164,270 bp,and a total number of plastome genes of about 130.Plastome microsatellites(SSR)ranged in number from 48 to 77.Maximum Likelihood and Bayesian analyses of three plastome data sets consistently nested Parapteropyrum within the genus Fagopyrum.Furthermore,our analyses indicated that sampled woody genera of the family Polygonaceae are polyphyletic.Our study provides strong evidence that the woody Parapteropyrum tibeticum,which is distantly related to woody genera sampled here,should be taxonomically placed under Fagopyrum as Fagopyrum tibeticum.展开更多
Establishing how lineages with similar traits are phylogenetically related remains critical for understanding the origin of biodiversity on Earth.Floral traits in plants are widely used to explore phylogenetic relatio...Establishing how lineages with similar traits are phylogenetically related remains critical for understanding the origin of biodiversity on Earth.Floral traits in plants are widely used to explore phylogenetic relationships and to delineate taxonomic groups.The subtribe Swertiinae(Gentianaceae)comprises more than 350 species with high floral diversity ranging from rotate to tubular corollas and possessing diverse nectaries.Here we performed phylogenetic analysis of 60 species from all 15 genera of the subtribe Swertiinae sensu Ho and Liu,representing the range of floral diversity,using data from the nuclear and plastid genomes.Extensive topological conflicts were present between the nuclear and plastome trees.Three of the 15 genera represented by multiple species are polyphyletic in both trees.Key floral traits including corolla type,absence or presence of lobe scales,nectary type,nectary position,and stigma type are randomly distributed in the nuclear and plastome trees without phylogenetic correlation.We also revealed the likely ancient hybrid origin of one large clade comprising 10 genera with diverse floral traits.These results highlight the complex evolutionary history of this subtribe.The phylogenies constructed here provide a basic framework for further exploring the ecological and genetic mechanisms underlying both species diversification and floral diversity.展开更多
基金supported by the Second Tibetan Plateau Scientific Expedition and Research program (No. 2019QZKK0502)Strategic Priority Research Program of Chinese Academy of Sciences (No. XDB31010300)+1 种基金Fundamental Research Funds for the Central UniversitiesInternational Collaboration 111 Program (BP0719040)。
文摘The identification and understanding of cryptic intraspecific evolutionary units(lineages) are crucial for planning effective conservation strategies aimed at preserving genetic diversity in endangered species.However, the factors driving the evolution and maintenance of these intraspecific lineages in most endangered species remain poorly understood. In this study, we conducted resequencing of 77 individuals from 22 natural populations of Davidia involucrata, a “living fossil” dove tree endemic to central and southwest China. Our analysis revealed the presence of three distinct local lineages within this endangered species, which emerged approximately 3.09 and 0.32 million years ago. These divergence events align well with the geographic and climatic oscillations that occurred across the distributional range.Additionally, we observed frequent hybridization events between the three lineages, resulting in the formation of hybrid populations in their adjacent as well as disjunct regions. These hybridizations likely arose from climate-driven population expansion and/or long-distance gene flow. Furthermore, we identified numerous environment-correlated gene variants across the total and many other genes that exhibited signals of positive evolution during the maintenance of two major local lineages. Our findings shed light on the highly dynamic evolution underlying the remarkably similar phenotype of this endangered species. Importantly, these results not only provide guidance for the development of conservation plans but also enhance our understanding of evolutionary past for this and other endangered species with similar histories.
基金This work was funded by the National Natural Science Foundation of China(grant No.31590821).
文摘The phylogenetic position of the monotypic woody Parapteropyrum(Polygonaceae)remains controversial.Parapteropyrum has been thought to be closely related to the woody genera of the tribe Atraphaxideae,although some evidence indicates that it nests within the herbal buckwheat genus Fagopyrum of tribe Polygoneae.In this study,we used plastome data to determine the phylogenetic position of Parapteropyrum(Fagopyrum)tibeticum.Different reference species were used to assemble plastomes of three species currently placed in the tribe Ataphaxideae:Parapteropyrum(Fagopyrum)tibeticum,Atraphaxis bracteata and Calligonum ebinuricum.Once assembled,plastomes were characterized and compared to plastomes of 12 species across the family Polygonaceae.Phylogenetic analyses of Polygonaceae were performed using whole plastome,all plastome genes,and single-copy genes.Plastomes assembled using different reference plastomes did not differ;however,annotations showed small variation.Plastomes of Parapteropyrum(Fagopyrum)tibeticum,A.bracteata and C.ebinuricum have the typical quadripartite structure with lengths between 159,265 bp and 164,270 bp,and a total number of plastome genes of about 130.Plastome microsatellites(SSR)ranged in number from 48 to 77.Maximum Likelihood and Bayesian analyses of three plastome data sets consistently nested Parapteropyrum within the genus Fagopyrum.Furthermore,our analyses indicated that sampled woody genera of the family Polygonaceae are polyphyletic.Our study provides strong evidence that the woody Parapteropyrum tibeticum,which is distantly related to woody genera sampled here,should be taxonomically placed under Fagopyrum as Fagopyrum tibeticum.
基金supported by the Natural Science Foundation of China(32170221)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB31000000)Fundamental Research Funds for the Central Universities(YJ201936,SCU2019D013 and 2020SCUNL20)。
文摘Establishing how lineages with similar traits are phylogenetically related remains critical for understanding the origin of biodiversity on Earth.Floral traits in plants are widely used to explore phylogenetic relationships and to delineate taxonomic groups.The subtribe Swertiinae(Gentianaceae)comprises more than 350 species with high floral diversity ranging from rotate to tubular corollas and possessing diverse nectaries.Here we performed phylogenetic analysis of 60 species from all 15 genera of the subtribe Swertiinae sensu Ho and Liu,representing the range of floral diversity,using data from the nuclear and plastid genomes.Extensive topological conflicts were present between the nuclear and plastome trees.Three of the 15 genera represented by multiple species are polyphyletic in both trees.Key floral traits including corolla type,absence or presence of lobe scales,nectary type,nectary position,and stigma type are randomly distributed in the nuclear and plastome trees without phylogenetic correlation.We also revealed the likely ancient hybrid origin of one large clade comprising 10 genera with diverse floral traits.These results highlight the complex evolutionary history of this subtribe.The phylogenies constructed here provide a basic framework for further exploring the ecological and genetic mechanisms underlying both species diversification and floral diversity.
