The tree of life is central to evolutionary biology, yet resolving deep, recalcitrant phylogenetic relationships remains challenging due to complex processes such as incomplete lineage sorting (ILS), hybridization, and polyploidization. Although previous phylogenetic studies have advanced our understanding of Leguminosae (Fabaceae), a species-rich and ecologically diverse family, many deep relationships at the tribal and higher levels remain unresolved. Incorporating newly generated genome skimming data for 231 species with previously issued plastid genomic, mitochondrial genomic, and transcriptomic data, we reconstructed a phylogeny of the family using whole plastomes, 39 mitochondrial genes, and 1559 low-copy nuclear genes, achieving dense taxonomic sampling across almost all recognized tribes and major unplaced lineages. Our results supported the monophyly of the six subfamilies and 49 recognized tribes, identified 10 clades worthy of recognition as new tribes in subfamily Papilionoideae, and clarified many contentious relationships. However, nuclear-nuclear and cytonuclear conflicts persist at multiple nodes among trees inferred from different data sets and analytical methods. We proposed the most probable resolution for 22 contentious nodes by applying nuclear gene tree quartet analysis with corroboration from support of nuclear maximum likelihood and ASTRAL trees. Our results indicate that ILS significantly contributes to observed phylogenetic conflicts, whereas gene flow represents an additional and previously underappreciated factor that mainly contributes to cytonuclear conflicts, particularly along the branches of the Angylocalyceae + Dipterygeae + Amburaneae (ADA) clade and Wisterieae. These processes likely underlie recalcitrant phylogenetic relationships, such as those within the 50-kb inversion clade of Papilionoideae. Our study uses multiple data partitions and analytical methods to resolve contentious phylogenetic relationships in Leguminosae, resulting in a robust phylogenomic framework to guide further investigations in this economically important and exceptionally diverse family.

Polyploidy or whole-genome duplication (WGD) is a significant evolutionary force. However, the mechanisms governing polyploid genome evolution remain unclear, limited largely by a lack of functional analysis tools in organisms that best exemplify the earliest stages of WGD. Tragopogon (Asteraceae) includes an evolutionary model system for studying the immediate consequences of polyploidy. In this study, we significantly improved the transformation system and obtained genome-edited T. porrifolius (2x) and T. mirus (4x) primary generation (T0) individuals. Using CRISPR/Cas9, we knocked out the dihydroflavonol 4-reductase (DFR) gene, which controls anthocyanin synthesis, in both species. All transgenic allotetraploid T. mirus individuals had at least one mutant DFR allele, and 71.4% had all four DFR alleles edited. The resulting mutants lacked anthocyanin, and these mutations were inherited in the T1 generation. This study demonstrates a highly efficient CRISPR platform, producing genome-edited Tragopogon individuals that have completed the life cycle. The approaches used and challenges faced in building the CRISPR system in Tragopogon provide a framework for building similar systems in other non-genetic models. Genome editing in Tragopogon paves the way for novel functional biology studies of polyploid genome evolution and the consequences of WGD on complex traits, holding enormous potential for both basic and applied research.

Recently formed allopolyploid species offer unprecedented insights into the early stages of polyploid evolution. This review examines seven well-studied neopolyploids (we use 'neopolyploid' to refer to very recently formed polyploids, i.e. during the past 300 years), spanning different angiosperm families, exploring commonalities and differences in their evolutionary trajectories. Each neopolyploid provides a unique case study, demonstrating both shared patterns, such as rapid genomic and phenotypic changes, and unique responses to hybridization and genome doubling. While previous studies of these neopolyploids have improved our understanding of polyploidy, significant knowledge gaps remain, highlighting the need for further research into the varied impacts of whole-genome duplication on gene expression, epigenetic modifications, and ecological interactions. Notably, all of these neopolyploids have spontaneously arisen due to human activity in natural environments, underscoring the profound consequences of polyploidization in a rapidly changing world. Understanding the immediate effects of polyploidy is crucial not only for evolutionary biology but also for applied practices, as polyploidy can lead to novel traits, as well as stress tolerance and increased crop yields. Future research directions include investigating the genetic and epigenetic mechanisms underlying polyploid evolution, as well as exploring the potential of neopolyploids for crop improvement and environmental adaptation.

Biological invasions are profoundly altering Earth's ecosystems, but generalities about the effects of nonnative species on the diversity and productivity of native communities have been elusive. This lack of generality may reflect the limited spatial and temporal extents of most previous studies. Using >5 million tree measurements across eastern US forests from 1995 to 2023, we quantified temporal trends in tree diversity and biomass. We then analyzed community-level changes in native tree diversity and biomass in relation to nonnative tree invasion and native species colonization. Across the entire eastern United States, native tree species richness decreased over time in plots where nonnatives occurred, whereas nonnative species richness and the biomass of both natives and nonnatives increased over time. At the community scale, native richness tended to decline following nonnative invasion, whereas native biomass and richness-independent measures of trait and phylogenetic diversity tended to remain stable. These patterns can be explained by the rarity of the displaced native species and their functional and phylogenetic similarity to native species that survived nonnative invasions. In contrast, native survivors tended to be functionally distinct from nonnative invaders, suggesting an important role for niche partitioning in community dynamics. Colonization by previously absent native species was associated with an increase in native richness (beyond the addition of native colonizers), which contrasts with declines in native richness that tended to follow nonnative invasion. These results suggest a causal role for nonnative species in the native richness decline of invaded communities.

The Qinghai-Tibet Plateau (QTP) harbors extraordinarily high levels of biodiversity and endemism. The region is warming at a rate twice the global average, yet the evolutionary dynamics of its unique biota are poorly understood. Here, we used the endemic land plant genera of the QTP to investigate how its floristic endemism was shaped over time by Cenozoic geoclimatic changes. We first clarified that the QTP hosts 82 endemic land plant genera; we found that the origins of these endemic genera were most likely driven by ecological niche and elevation differentiation, caused by the uplift of the QTP and associated climate change. By sampling 37 land plant clades that together encompass 1,740 species, covering all 82 endemic genera, we show that QTP floristic endemism had emerged by the Early Eocene. Furthermore, the unique biodiversity of the QTP comprises a mix of indigenous elements and immigrants. Among the three subregions of the QTP (Plateau Platform, Himalaya, and the Hengduan Mountains), the processes associated with floristic endemism are asynchronous, reflecting different geoclimatic events with the Miocene as a particularly critical period. The relative contributions of in situ speciation and immigration to the unique biodiversity of the three subregions are also markedly different; in situ speciation dominated in the Hengduan Mountains, which hosts the oldest endemic components of the flora and has served as an important "pump" and "sink" of unique biodiversity. These findings provide insights into how past geoclimatic events may have shaped floristic endemism on the QTP and also have important conservation implications.

AimA species' rate of climatic niche evolution may reflect its ability to survive changing climates. Yet large-scale studies of these rates remain limited. Here, we assessed global patterns in climatic niche rates among angiosperms and explored the potential drivers shaping these patterns.LocationGlobal.Time PeriodCurrent.Major Taxa StudiedAngiosperms.MethodsWe estimated broad-scale climatic niches for 231,567 angiosperm species based on distributional data from over 1100 sources. By integrating a published phylogeny of angiosperms, we estimated rates of climatic niche change for each extant species as the difference between its current and ancestral niche divided by the species' age. Global patterns were analysed by averaging rates for all the species found in each geographic unit. We used multiple statistical models to explore the relative contributions of niche width and climatic seasonality to shaping these geographic patterns of niche evolution. We analysed patterns of niche evolution and their underlying drivers separately for temperature-related and precipitation-related niches and for different directions of niche evolution (i.e., increases and decreases in species' temperature and precipitation niche values when compared to their most recent ancestors).ResultsRates for temperature variables increased with latitude, whereas rates for precipitation variables decreased with latitude. These opposing patterns in temperature and precipitation rates were related to opposing latitudinal patterns in climatic seasonality and species' niche widths for temperature and precipitation. Rates also differed for different directions of niche evolution, with different patterns associated with changes to warmer vs. cooler climates and wetter vs. drier climates.Main ConclusionsOur results revealed large-scale geographic patterns in rates of climatic niche change for temperature and precipitation for the largest clade of angiosperms and their underlying drivers. These findings may have important implications for species' abilities to respond to recent climate change.

Southwest China is characterized by high plateaus, large mountain systems, and deeply incised dry valleys formed by major rivers and their tributaries. Despite the considerable attention given to alpine plant radiations in this region, the timing and mode of diversification of the numerous dry valley plant lineages remain unknown. To address this knowledge gap, we investigated the macroevolution of Isodon (Lamiaceae), a lineage commonly distributed in the dry valleys in southwest China and wetter areas of Asia and Africa. We reconstructed a robust phylogeny encompassing nearly 90% of the approximately 140 extant Isodon species using transcriptome and genome-resequencing data. Our results suggest a rapid radiation of Isodon during the Pliocene that coincided with a habit shift from herbs to shrubs and a habitat shift from humid areas to dry valleys. The shrubby growth form likely acted as a preadaptation allowing for the movement of Isodon species into these dry valleys. Ecological analyses highlight drought-related factors as key drivers influencing the niche preferences of different growth forms and species richness of Isodon. The interplay between topography and the development of the East Asian monsoon since the middle Miocene likely contributed to the formation of the dry valley biome in southwest China. This study enhances our understanding of evolutionary dynamics and ecological drivers shaping the distinctive flora of southwest China and reveals the strategies employed by montane plants in response to climate change and dryland expansion, thus facilitating conservation efforts globally.

Polyploidy, also known as whole-genome duplication (WGD), is a significant evolutionary force in green plants, especially angiosperms. The dynamic nature of polyploid genomes generates genetic diversity and drives the evolution of novel traits and adaptations. Pangenomics is emerging as a major frontier in plant genome research, with a rapidly growing number of pangenomes for individual species and associated analyses providing novel agronomic and evolutionary insights. Polyploid genome analysis can be confounded by intraspecific variation when relying on a single reference genome assembly. The use of pangenomes that better represent the genomic diversity of a species helps overcome this limitation. ­However, a major gap remains between the number of pangenomic studies in polyploid compared to diploid species, despite the widespread prevalence of WGD, limiting the potential of the pangenome framework for characterizing and understanding polyploid genomes. Furthermore, most polyploid pangenome studies have focused on domesticated crop species, and natural populations have rarely been examined. In addition to applications in crop improvement, pangenomes can provide insights into the ecological and evolutionary impact of polyploidy. Here, we summarize recent pangenome studies in polyploid plants and highlight promising topics for future research. We hope this article will encourage the growth of pangenomic studies in polyploid systems, particularly in natural populations.

Polyploidy, or whole-genome duplication (WGD), is a significant evolutionary force. Following allopolyploidy, duplicate gene copies (homeologs) have divergent evolutionary trajectories: some genes are preferentially retained in duplicate, while others tend to revert to single-copy status. Examining the effect of homeolog loss (i.e., changes in gene dosage) on associated phenotypes is essential for unraveling the genetic mechanisms underlying polyploid genome evolution. However, homeolog-specific editing has been demonstrated in only a few crop species and remains unexplored beyond agricultural applications. Tragopogon (Asteraceae) includes an evolutionary model system for studying the immediate consequences of polyploidy in nature. In this study, we developed a CRISPR-mediated homeolog-specific editing platform in allotetraploid T. mirus. Using the MYB10 and DFR genes as examples, we successfully knocked out the targeted homeolog in T. mirus (4x) without editing the other homeolog (i.e., no off-target events). The editing efficiencies, defined as the percentage of plants with at least one allele of the targeted homeolog modified, were 35.7% and 45.5% for MYB10 and DFR, respectively. Biallelic modification of the targeted homeolog occurred in the T0 generation. These results demonstrate the robustness of homeolog-specific editing in polyploid Tragopogon, laying the foundation for future studies of genome evolution following WGD in nature.

The origin and phylogenetic distribution of symbiotic associations between nodulating angiosperms and nitrogen- fixing bacteria have long intrigued biologists. Recent comparative evolutionary analyses have yielded alternative hypotheses: a multistep pathway of independent gains and losses of root nodule symbiosis vs. a single gain followed by numerous losses. A detailed reconstruction of the history of genes involved in signaling between nitrogen- fixing bacteria and potential hosts, particularly lipo- chitooligosaccharide (LCO) signaling, is needed to distinguish between these hypotheses. LCO recognition by plants involves the Nod Factor Perception (NFP) gene family; in the legume model Medicago truncatula (Fabales), MtNFP is essential for establishing rhizobial symbiosis. Here, we document convergent evolution of NFP, indicating multiple origins of LCO- driven symbiosis. In contrast to previous models that explain the recruitment of NFP via a single duplication in the ancestor of the nitrogen- fixing clade, our phylogenomic and synteny results suggest this duplication does not span the entire clade. Tandem duplication in a common ancestor of Cucurbitales and Rosales resulted in the NFP1 and NFP2 groups. In contrast, the phylogenetically closest paralog of MtNFP is MtLYR1, located on a different chromosome within a large syntenic block. All available data indicate that a large- scale duplication resulted in MtNFP and MtLYR1, likely corresponding to a whole- genome duplication in an ancestor of subfamily Papilionoideae of Fabaceae. We show that MtNFP and the NFP2- like group are not orthologous, indicating multiple independent gains of NFP- based LCO signaling. This molecular convergence provides a possible mechanism for multiple gains of root nodule symbiosis across the nitrogen- fixing clade.

The origin and phylogenetic distribution of symbiotic associations between nodulating angiosperms and nitrogen-fixing bacteria have long intrigued biologists. Recent comparative evolutionary analyses have yielded alternative hypotheses: a multistep pathway of independent gains and losses of root nodule symbiosis vs. a single gain followed by numerous losses. A detailed reconstruction of the history of genes involved in signaling between nitrogen-fixing bacteria and potential hosts, particularly lipo-chitooligosaccharide (LCO) signaling, is needed to distinguish between these hypotheses. LCO recognition by plants involves the Nod Factor Perception (NFP) gene family; in the legume model Medicago truncatula (Fabales), MtNFP is essential for establishing rhizobial symbiosis. Here, we document convergent evolution of NFP, indicating multiple origins of LCO-driven symbiosis. In contrast to previous models that explain the recruitment of NFP via a single duplication in the ancestor of the nitrogen-fixing clade, our phylogenomic and synteny results suggest this duplication does not span the entire clade. Tandem duplication in a common ancestor of Cucurbitales and Rosales resulted in the NFP1 and NFP2 groups. In contrast, the phylogenetically closest paralog of MtNFP is MtLYR1, located on a different chromosome within a large syntenic block. All available data indicate that a large-scale duplication resulted in MtNFP and MtLYR1, likely corresponding to a whole-genome duplication in an ancestor of subfamily Papilionoideae of Fabaceae. We show that MtNFP and the NFP2-like group are not orthologous, indicating multiple independent gains of NFP-based LCO signaling. This molecular convergence provides a possible mechanism for multiple gains of root nodule symbiosis across the nitrogen-fixing clade.

Although the frequency of ancient hybridization across the Tree of Life is greater than previously thought, little work has been devoted to uncovering the extent, timeline, and geographic and ecological context of ancient hybridization. Using an expansive new dataset of nuclear and chloroplast DNA sequences, we conducted a multifaceted phylogenomic investigation to identify ancient reticulation in the early evolution of oaks(Quercus). We document extensive nuclear gene tree and cytonuclear discordance among major lineages of Quercus and relatives in Quercoideae. Our analyses recovered clear signatures of gene flow against a backdrop of rampant incomplete lineage sorting, with gene flow most prevalent among major lineages of Quercus and relatives in Quercoideae during their initial radiation, dated to the Early-Middle Eocene. Ancestral reconstructions including fossils suggest ancestors of Castanea + Castanopsis, Lithocarpus, and the Old World oak clade probably co-occurred in North America and Eurasia, while the ancestors of Chrysolepis, Notholithocarpus, and the New World oak clade co-occurred in North America, offering ample opportunity for hybridization in each region.Our study shows that hybridization—perhaps in the form of ancient syngameons like those seen today—has been a common and important process throughout the evolutionary history of oaks and their relatives. Concomitantly, this study provides a methodological framework for detecting ancient hybridization in other groups.

PREMISE:The demographic histories of temperate plants in Northeast Asia in response to Quaternary climate oscillations have long been the focus of evolutionary biologists, but have rarely been studied in herbaceous plants. Here, we investigated the phylogeographic patterns of Mukdenia and Oresitrophe. METHODS:We sequenced two plastid regions for O. rupifraga (22 populations, 222 individuals), M. acanthifolia (five populations, 50 individuals), and M. rossii (14 populations, 139 individuals). To better understand the phylogeographic patterns of these species, we analyzed genetic diversity/structure, divergence times, demographic history, and distributional changes (with ecological niche modeling). We compared the inferred niche space of these species and addressed isolation by distance (IBD) and isolation by environment (IBE). RESULTS:We confirmed the monophyly of each species and detected a phylogeographic division corresponding to an arid belt in North China. Oresitrophe rupifraga is inferred to have contracted into four refugia during Pleistocene interglacial periods. Mukdenia acanthifolia and M. rossii appear to have retreated to the Changbai Mountains and Korean Peninsula during that time. In contrast, a larger potential geographic distribution was inferred for each species during glacial periods. Significant ecological niche differentiation was detected among the three species, which may have been associated with their genetic divergence. CONCLUSIONS:Refugial isolation, climatic barriers, and niche differentiation likely influenced the genetic divergence of Oresitrophe and Mukdenia. Our study has implications for the structure of plant diversity in temperate deciduous forests of Northeast Asia and provides insights into conservation units worthy of protection and management for species of both genera.

Rosids, comprising 90,000-120,000 species, form a large clade of angiosperms, including extensively studied families with many economically and scientifically important plants. They are also ecologically important, dominating many temperate and tropical ecosystems. Great progress in understanding rosid phylogenetic relationships has facilitated evolutionary studies, but phylogenetic uncertainties remain. To construct a more comprehensive nuclear phylogeny with expanded taxon coverage at the familial levels, we generated 203 new transcriptomes and two shotgun genomes. Along with other available data sets, our sample includes 419 eudicots, including 316 rosids, representing 83 families and all 16 rosid orders. Compared to the 1KP study, our highly resolved rosid phylogeny provides strongly supported internal relationships for one additional order and 16 families. We uncovered cytoplasmic-nuclear discordance for several deep rosid relationships with possible evidence of hybridization/gene flow and incomplete lineage sorting. By tracing ancestral states of morphological characters, we revealed putative floral evolutionary trends in some major clades. We detected strong evidence for 27 putative whole-genome duplication (WGD) events distributed across 20 rosid families, including five novel WGDs. Additionally, our expanded taxon sampling allowed for revised phylogenetic positions of several previously reported WGD events. Most of the supported WGDs correspond to origins of families or large subclades and occurred near times of geological and global climate upheavals, including those at the Cretaceous-Paleogene boundary. Our findings support the idea that large-scale genomic changes and key morphological innovations might have contributed to adaptive evolution and increased biodiversity in rosids.

The theoretical population dynamics of autopolyploids – organisms with more than two genome copies of a single ancestral species – and their diploid progenitors have been extensively studied. The acquisition of multiple genome copies, being in essence a stochastic process, strongly suggests a probabilistic approach to examine the long-term dynamics of a population with multiple cytotypes. Yet, our current understanding of empirical evidence on the dynamics of autopolyploid populations has not incorporated stochastic population dynamics. To investigate the factors contributing to the probability and stability of coexisting cytotypes, we designed a new population dynamics model with demographic and environmental stochasticities to simulate the formation, establishment, and persistence of diploids, triploids, and autotetraploids over time when gene flow is allowed among cytotypes. Contrary to previous research, increased selfing rates and pronounced reproductive isolation stabilized the long-run coexistence of multiple cyto-types. In stressful environments, these dynamics become much more complex, and our stochastic modeling approach helped reveal the resulting intricacies that give tetraploids competitive advantage over their diploid progenitors. Our work is fundamental to a better understanding of the dynamics of coexistence of multiple cytotypes and is a necessary step for further work modeling the dynamics between an autopolyploid and its diploid progenitor.

Reticulate evolution and recalcitrant phylogenetic relationships are common in the East Asian evergreen broad-leaved forests (EA-EBLFs),. Hybridization and incomplete lineage sorting (ILS) can both occur during diversification of these forests, yet the extent of ILS has often been overlooked. Among floristic elements in the EA-EBLFs, plant genera that are disjunctly distributed between eastern Asia and eastern North America (EA-ENA disjuncts) provide an excellent system to explore the magnitude of hybridization and ILS after vicariance and long-distance dispersal. Here, we investigated the evolutionary history of Stewartia L. (Theaceae), one of the EA-ENA disjuncts whose major members inhabit the EA-EBLFs (ca. 20 spp. in EA vs. two spp. in ENA) using target enrichment sequence data obtained from Angiosperms353. Based on nearly complete taxon sampling, we recovered two Stewartia clades (the EA deciduous and evergreen clades) in the EA-EBLFs. Our estimates indicate that these two clades started to diversify in the late Miocene, and the evergreen clade showed a higher diversification rate than the deciduous clade. The SNaQ and NANUQ analyses detected hybridization signals within both clades, primarily involving S. serrata and S. tonkinensis, respectively. In addition, the QuIBL analysis revealed co-occurring introgression and ILS in 98/105 and 318/360 tested triplets (Δ BIC < - 10) in the deciduous and evergreen clades, respectively. The Phytop analysis further supported ILS as the primary source of gene-tree discordance. Our study reveals complex phylogenetic and evolutionary patterns in EA-EBLF endemics and highlights the importance of hybridization and ILS in this region.

The evolutionary histories of many polyploid plant species are difficult to resolve due to a complex interplay of hybridization, incomplete lineage sorting, and missing diploid progenitors. In the case of octoploid strawberry with four subgenomes designated ABCD, the identities of the diploid progenitors for subgenomes C and D have been subject to much debate. By integrating new sequencing data from North American diploids with reticulate phylogeny and admixture analyses, we uncovered introgression from an extinct or unsampled species in the clade of Fragaria viridis, Fragaria nipponica, and Fragaria nilgerrensis into the donor of subgenome A of octoploid Fragaria prior to its divergence from F. vesca subsp. bracteata. We also detected an introgression event from F. iinumae into an ancestor of F. nipponica and F. nilgerrensis. Using an LTR-age-distribution-based approach, we estimate that the octoploid and its intermediate hexaploid and tetraploid ancestors emerged approximately 0.8, 2, and 3 million years ago, respectively. These results provide an explanation for previous reports of F. viridis and F. nipponica as donors of the C and D subgenomes and suggest a greater role than previously thought for homoploid hybridization in the diploid progenitors of octoploid strawberry. The integrated set of approaches used here can help advance polyploid genome analysis in other species where hybridization and incomplete lineage sorting obscure evolutionary relationships.

The macroevolutionary processes that have shaped biodiversity across the temperate realm remain poorly understood and may have resulted from evolutionary dynamics related to diversification rates, dispersal rates, and colonization times, closely coupled with Cenozoic climate change. We integrated phylogenomic, environmental ordination, and macroevolutionary analyses for the cosmopolitan angiosperm family Rhamnaceae to disentangle the evolutionary processes that have contributed to high species diversity within and across temperate biomes. Our results show independent colonization of environmentally similar but geographically separated temperate regions mainly during the Oligocene, consistent with the global expansion of temperate biomes. High global, regional, and local temperate diversity was the result of high in situ diversification rates, rather than high immigration rates or accumulation time, except for Southern China, which was colonized much earlier than the other regions. The relatively common lineage dispersals out of temperate hotspots highlight strong source-sink dynamics across the cosmopolitan distribution of Rhamnaceae. The proliferation of temperate environments since the Oligocene may have provided the ecological opportunity for rapid in situ diversification of Rhamnaceae across the temperate realm. Our study illustrates the importance of high in situ diversification rates for the establishment of modern temperate biomes and biodiversity hotspots across spatial scales.

The angiosperm family Elaeagnaceae comprises three genera and ca.100 species distributed mainly in Eurasia and North America.Little family-wide phylogenetic and biogeographic research on Elaeagnaceae has been conducted,limiting the application and preservation of natural genetic resources.Here,we reconstructed a strongly supported phylogenetic framework of Elaeagnaceae to better understand inter-and intrageneric relationships,as well as the origin and biogeographical history of the family.For this purpose,we used both nuclear and plastid sequences from Hyb-Seq and genome skimming approaches to reconstruct a well-supported phylogeny and,along with current distributional data,infer historical biogeographical processes.Our phylogenetic analyses of both nuclear and plastid data strongly support the monophyly of Elaeagnaceae and each of the three genera.Elaeagnus was resolved as sister to the well-supported clade of Hippophae and Shepherdia.The intrageneric relationships of Elaeagnus and Hippophae were also well resolved.High levels of nuclear gene tree conflict and cytonuclear discordance were detected within Elaeagnus,and our analyses suggest putative ancient and recent hybridization.We inferred that Elaeagnaceae originated at ca.90.48 Ma(95％CI=89.91-91.05 Ma),and long-distance dispersal likely played a major role in shaping its intercontinentally disjunct distribution.This work presents the most comprehensive phylogenetic framework for Elaeagnaceae to date,offers new insights into previously unresolved relationships in Elaeagnus,and provides a foundation for further studies on classification,evolution,biogeography,and conservation of Elaeagnaceae.

Vaccinieae is a morphologically diverse and species-rich (∼1430 species) tribe in Ericaceae. Although the majority of diversity is tropical, Vaccinieae are best known for temperate crops (i.e., blueberries, cranberries, huckleberries, lingonberries) in Vaccinium. Vaccinium itself (∼500 species) has been previously suggested as highly polyphyletic and taxonomic boundaries among many of the other genera in the tribe remain uncertain. We assessed the evolutionary history of Vaccinieae with phylogenomic analyses based on a target-enrichment dataset containing 256 low-copy nuclear loci and 210 species representing 30 of the 35 genera in the tribe and 25 of the 29 sections of Vaccinium. We conducted time-calibrated biogeographic analyses and diversification analyses to explore the area of origin and global dispersal history of the tribe. The analysis recovered a temperate North American origin for Vaccinieae approximately 30 million years ago. Tropical diversity of Vaccinieae was inferred to result from multiple, independent movements into the tropics from north-temperate ancestors. Diversification rate increases corresponded to radiation into the Andes and SE Asia. The pseudo-10-locular ovary evolved once in the tribe from the five-locular state, coinciding with the diversification of a major clade that includes most Asian Vaccinium and the group from which commercial blueberries are derived (V. sect. Cyanococcus). A reconstruction from available chromosome counts suggests that a major polyploid event predated the evolution of nearly half the diversity of Vaccinieae. The extent of polyphyly in Vaccinium documented here supports the need for a generic reclassification of the tribe.