When benefiting other beneficiaries,cushion plants may reciprocally receive feedback effects.The feedback effects on different sex morphs,however,remains unclear.In this study,taking the gynodioecious Arenaria polytri...When benefiting other beneficiaries,cushion plants may reciprocally receive feedback effects.The feedback effects on different sex morphs,however,remains unclear.In this study,taking the gynodioecious Arenaria polytrichiodes as a model species,we aimed to assess the sex-specific facilitation intensity of cushion plant by measuring the beneficiary cover ratio,and to assess the potential costs in cushion reproductive functions by measuring the flower and fruit cover ratios.The total beneficiary cover ratio was similar between females and hermaphrodites.Females produced much less flowers but more fruits than hermaphrodites.These results suggested that females and hermaphrodites possess similar facilitation intensity,and female cushion A.polytrichoides may allocate more resources saved from pollen production to seed production,while hermaphrodites possibly allocate more resources to pollen production hence reducing seed production.The surface areas covered by beneficiaries produced less flowers and fruits than areas without beneficiaries.In addition,strong negative correlations between beneficiary cover and flower cover were detected for both females and hermaphrodites,but the correlation strength were similar for these two sex morphs.However,the correlation between beneficiary cover and fruit cover was only significantly negative for females,suggesting that beneficiary plants negatively affect fruit reproduction of females while have neutral effects on hermaphrodites.All the results suggest that to facilitate other beneficiaries can induce reproductive costs on cushion A.polytrichoides,with females possibly suffering greater cost than hermaphrodites.Such differentiation in reproductive costs between sex morphs,in long-term perspective,may imply sex imbalance in population dynamics.展开更多
Sexual systems play important roles in angiosperm evolution and exhibit substantial variations among different floras. Thus, studying their evolution in a whole flora is crucial for understanding the formation and mai...Sexual systems play important roles in angiosperm evolution and exhibit substantial variations among different floras. Thus, studying their evolution in a whole flora is crucial for understanding the formation and maintenance of plant biodiversity and predicting its responses to environmental change. In this study, we determined the patterns of plant sexual systems and their associations with geographic elements and various life-history traits in dry-hot valley region of southwestern China, an extremely vulnerable ecosystem. Of the 3166 angiosperm species recorded in this area, 74.5% were hermaphroditic,13.5% were monoecious and 12% were dioecious, showing a high incidence of diclinous species. Diclinous species were strongly associated with tropical elements, whereas hermaphroditic species were strongly associated with temperate and cosmopolitan elements. We also found that hermaphroditism was strongly associated with showy floral displays, specialist entomophily, dry fruits and herbaceous plants.Dioecy was strongly associated with inconspicuous, pale-colored flowers, generalist entomophily, fleshy fruits, and woody plants, whereas monoecy was strongly associated with inconspicuous, pale-colored flowers, anemophily, dry fruits, and herbaceous plants. In addition, hermaphroditic species with generalist entomophily tended to flower in the dry season, whereas diclinous species with specialist entomophily tended to flower in the rainy season. However, independent of sexual systems, plants that produce dry fruits tended to flower in the rainy season and set fruits in the dry season, but the opposite pattern was found for fleshy fruit-producing plants. Our results suggest that in the dry-hot valleys, plant sexual systems are associated with geographic elements as well as various life-history traits that are sensitive to environmental change.展开更多
Eremurus was described at the beginning of the 19th century.However,due to limited sampling and the small number of gene markers to date,its phylogeny and evolution are largely unknown.In this study,we analyzed plasto...Eremurus was described at the beginning of the 19th century.However,due to limited sampling and the small number of gene markers to date,its phylogeny and evolution are largely unknown.In this study,we analyzed plastomes from 27 species belonging to 2 subgenera and 3 sections of Eremurus,which are found in Central Asia(its center of diversity)and China.We also analyzed nuclear DNA ITS of 33 species,encompassing all subgenera and sections of the genus in Central Asia,southwest Asia and China.Our findings revealed that the genus was monophyletic,although both subgenera Eremurus and Henningia were found to be paraphyletic.Both plastome and nrDNA-based phylogenetic trees had three clades that did not reflect the current taxonomy of the genus.Our biogeographical and time-calibrated trees suggest that Eremurus originated in the ancient Tethyan area in the second half of the Eocene.Diversification of Eremurus occurred from the early Oligocene to the late Miocene.Paratethys Sea retreat and several orogenetic events,such as the progressive uplift of the Qinghai-Tibet Plateau and surrounding mountain belts(Altai,Pamir,Tian Shan),caused serious topographic and climate(aridification)changes in Central Asia that may have triggered a split of clades and speciation.In this transformed Central Asia,speciation proceeded rapidly driven mainly by vicariance caused by numerous mountain chains and specialization to a variety of climatic,topographic and soil conditions that exist in this region.展开更多
Brain–computer interface (BCI) systems, such as the P300 speller, enable patients to express intentions withoutnecessitating extensive training.However, the complexity of operational instructions and the slow pace of...Brain–computer interface (BCI) systems, such as the P300 speller, enable patients to express intentions withoutnecessitating extensive training.However, the complexity of operational instructions and the slow pace of characterspelling pose challenges for some patients. In this paper, an image segmentation P300 selector based on YOLOv7-mask and DeepSORT is proposed. The proposed system utilizes a camera to capture real-world objects forclassification and tracking. By applying predefined stimulation rules and object-specificmasks, the proposed systemtriggers stimuli associated with the objects displayed on the screen, inducing the generation of P300 signals in thepatient’s brain. Its video processing mechanism enables the system to identify the target the patient is focusing oneven if the object is partially obscured, overlapped, moving, or changing in number. The system alters the target’scolor display, thereby conveying the patient’s intentions to caregivers. The data analysis revealed that the selfrecognitionaccuracy of the subjects using this method was between 92% and 100%, and the cross-subject P300recognition precision was 81.9%–92.1%. This means that simple instructions such as “Do not worry, just focuson what you desire” effectively discerned the patient’s intentions using the Image Segmentation-P300 selector. Thisapproach provides cost-effective support and allows patients with communication difficulties to easily express theirneeds.展开更多
Flower constancy describes the phenomenon that pollinators tend to successively visit flowers of a single species during foraging,reducing reproductive interference in natural communities.The extent of flower constanc...Flower constancy describes the phenomenon that pollinators tend to successively visit flowers of a single species during foraging,reducing reproductive interference in natural communities.The extent of flower constancy is largely determined by the floral traits of co-flowering species.Both higher inter-specific and lower intraspecific differences of floral traits should contribute to a higher level of flower constancy.However,previous studies mainly focused on interspecific difference,and the intraspecific variation(consistency)of floral traits received much less attention.We hypothesise that selection may favour lower intraspecific floral trait variation in communities composed of multiple co-flowering congeners.We investigated the floral colour variation of three focal Pedicularis species that share pollinators in 19communities composed of either single or multiple Pedicularis species.Colour was quantified using image-based colour analysis as perceived by pollinators.We found that most of the intrapopulation floral colour variation was below the colour discrimination threshold of bumblebees,implying strongly constrained by the visual selection by pollinators.Contrary to the hypothesis,there is no significant difference in intraspecific floral colour variation between different community contexts.It may be due to the relatively large interspecific floral colour differences of most co-flowering species.The influence of community context on intraspecific variation may be reflected in floral traits other than colours.展开更多
Background:Cholangiocarcinoma(CCA)is highly malignant and has a poor prognosis has a high malignant degree and poor prognosis.The purpose of this study is to develop a new prognostic model based on genes related to th...Background:Cholangiocarcinoma(CCA)is highly malignant and has a poor prognosis has a high malignant degree and poor prognosis.The purpose of this study is to develop a new prognostic model based on genes related to the tumor microenvironment(TME).Methods:Derived from the discerned differentially expressed genes within The Cancer Genome Atlas(TCGA)dataset,this investigation employed the methodology of weighted gene co-expression network analysis(WGCNA)to ascertain gene co-expressed modules intricately linked to the Tumor Microenvironment(TME)among Cholangiocarcinoma(CCA)patients.The genes associated with prognosis,as identified through Cox regression analysis,were employed in the formulation of a predictive model.This model underwent validation,leading to the development of a risk score formula and nomogram.Concurrently,we validated the model’s reliability using data from CCA patients in the Gene Expression Omnibus(GEO)database(accession:GSE107943).Results:6139 DEGs were divided into 10 co-expressed gene modules using WGCNA.Among these,two modules(blue module with 832 genes and brown module with 1379 genes)showed high correlation with the TME.Five prognostic genes(BNIP3,COL4A3,SPRED3,CEBPB,PLOD2)were identified through Cox regression analysis,and a prognostic model and risk score formula were developed based on these genes.Risk score formula:Risk score=BNIP3×1.70520-COL4A3×2.39815+SPRED3×1.17936+CEBPB×0.40456+PLOD2×0.24785.Kaplan-Meier survival analysis revealed that the survival probabilities of the low-risk group were significantly higher than those of the high-risk group.Furthermore,the related evaluation indexes suggested that the model exhibited strong predictive ability.Conclusion:The prognostic model,based on five TME-related genes(BNIP3,COL4A3,SPRED3,CEBPB,PLOD2),could accurately assess the prognosis of CCA patients to aid in guiding clinical decisions.展开更多
Plants have long been thought to be less dependent on pollinators for seed production at higher elevations due to adverse pollination environments.However,recent research has yet to consistently support the generality...Plants have long been thought to be less dependent on pollinators for seed production at higher elevations due to adverse pollination environments.However,recent research has yet to consistently support the generality of this expectation.In this study,we asked whether pollinator dependence decreases along an elevational gradient and how it varies with various reproductive traits.To answer these questions,we quantified pollinator-plant associations and various reproductive traits for 112 flowering plants spanning a large elevational gradient(990-4260 m a.s.l.)in the Qinghai-Tibet Plateau.We found that flowering plants in the Qinghai-Tibet Plateau region are highly dependent on pollinators for seed production(76.2%of seed production was contributed by animal pollinators and 44.6%of plants would produce no seed without pollinator visitation).Contrary to our expectation,there was no significant elevational gradient in pollinator dependence index.Although the pollinator dependence index was not significantly correlated with pollen limitation,flower size,floral longevity,or reward type,it was correlated with compatibility status and flowering time.These findings indicate that pollinator dependence does not decrease along an elevational gradient in the Qinghai-Tibet Plateau.Our study also highlights the severe vulnerability of flowering plant seed production to pollinator declines under global change in the Qinghai-Tibet Plateau region,particularly for early-flowering or self-incompatible plants growing at higher elevations(e.g.,subnival belt).展开更多
Brandisia is a shrubby genus of about eight species distributed basically in East Asian evergreen broadleaved forests(EBLFs),with distribution centers in the karst regions of Yunnan,Guizhou,and Guangxi in southwestern...Brandisia is a shrubby genus of about eight species distributed basically in East Asian evergreen broadleaved forests(EBLFs),with distribution centers in the karst regions of Yunnan,Guizhou,and Guangxi in southwestern China.Based on the hemiparasitic and more or less liana habits of this genus,we hypothesized that its evolution and distribution were shaped by the development of EBLFs there.To test our hypothesis,the most comprehensive phylogenies of Brandisia hitherto were constructed based on plastome and nuclear loci(nrDNA,PHYA and PHYB);then divergence time and ancestral areas were inferred using the combined nuclear loci dataset.Phylogenetic analyses reconfirmed that Brandisia is a member of Orobanchaceae,with unstable placements caused by nuclear-plastid incongruences.Within Brandisia,three major clades were well supported,corresponding to the three subgenera based on morphology.Brandisia was inferred to have originated in the early Oligocene(32.69 Mya)in the Eastern Himalayas-SW China,followed by diversification in the early Miocene(19.45 Mya)in karst EBLFs.The differentiation dates of Brandisia were consistent with the origin of keystone species of EBLFs in this region(e.g.,Fagaceae,Lauraceae,Theaceae,and Magnoliaceae)and the colonization of other characteristic groups(e.g.,Gesneriaceae and Mahonia).These findings indicate that the distribution and evolution of Brandisia were facilitated by the rise of the karst EBLFs in East Asia.In addition,the woody and parasitic habits,and pollination characteristics of Brandisia may also be the important factors affecting its speciation and dispersal.展开更多
Dear Editor,Understanding the evolution and survival mechanisms of endangered wild medicinal herbs is crucial for their cultivation,utilization,and conservation.The snow lotus species Saussurea involucrata(Kar.&Ki...Dear Editor,Understanding the evolution and survival mechanisms of endangered wild medicinal herbs is crucial for their cultivation,utilization,and conservation.The snow lotus species Saussurea involucrata(Kar.&Kir.)Sch.Bip.(2n=32)(i.e.the well-known Tianshan snow lotus)which belongs to the eudicot family Asteraceae,is a famous traditional Chinese medicinal herb having anti-inflammatory.展开更多
Foundational cushion plants can re-organize community structures and sustain a prominent proportion of alpine biodiversity,but they are sensitive to climate change.The loss of cushion species can have broad consequenc...Foundational cushion plants can re-organize community structures and sustain a prominent proportion of alpine biodiversity,but they are sensitive to climate change.The loss of cushion species can have broad consequences for associated biota.The potential plant community changes with the population dynamics of cushion plants remain,however,unclear.Using eight plant communities along a climatic and community successional gradient,we assessed cushion population dynamics,the underlying ecological constraints and hence associated plant community changes in alpine communities dominated by the foundational cushion plant Arenaria polytrichoides.The population dynamics of Arenaria are attributed to ecological constraints at a series of life history stages.Reproductive functions are constrained by increasing associated beneficiary plants;subsequent seedling establishment is constrained by temperature,water and light availability,extreme climate events,and interspecific competition;strong competitive exclusion may accelerate mortality and degeneration of cushion populations.Along with cushion dynamics,species composition,abundance and community structure gradually change.Once cushion plants completely degenerate,previously cushion-dominated communities shift to relatively stable communities that are overwhelmingly dominated by sedges.Climate warming may accelerate the degeneration process of A.polytrichoides.Degeneration of this foundational cushion plant will possibly induce massive changes in alpine plant communities and hence ecosystem functions in alpine ecosystems.The assessment of the population dynamics of foundation species is critical for an effective conservation of alpine biodiversity.展开更多
Eighty years ago, a botanical institute called"the Yunnan Provincial Institute of Agricultural and Forestry Botany"was jointly founded by the Jingsheng Biology Institute and the Yunnan State Department of Ed...Eighty years ago, a botanical institute called"the Yunnan Provincial Institute of Agricultural and Forestry Botany"was jointly founded by the Jingsheng Biology Institute and the Yunnan State Department of Education in Kunming. At that time, the Heilong Dragon Park became the institute's home (Fig. 1) and the research conducted there mostly focused on taxonomy and economical botany. When the institute came under the auspices of the Chinese Academy of Science, it still had fewer than 20 staff members.展开更多
1.Introduction The Hengduan Mountains region(HDM)in southwest China,one of the earth's 34 biodiversity hotspots,is characterized by its unique geology,dramatic topography,a climate where snow and below freezing te...1.Introduction The Hengduan Mountains region(HDM)in southwest China,one of the earth's 34 biodiversity hotspots,is characterized by its unique geology,dramatic topography,a climate where snow and below freezing temperatures can occur on any day of the year,by its location at elevations averaging between(1400e)2000 and4500(e5300)meters above sea level(m a.s.l.),and by one of展开更多
To detect the horizontal pattern of phylogenetic structure shown by alpine plants, we measured phylogenetic structure using net related index(NRI) and net nearest taxon index(NTI), and analyzed the phylogenetic struct...To detect the horizontal pattern of phylogenetic structure shown by alpine plants, we measured phylogenetic structure using net related index(NRI) and net nearest taxon index(NTI), and analyzed the phylogenetic structure patterns of alpine plants along longitude, latitude and environmental gradients in the Hengduan Mountains Region(HDMR). Our results show that: 1) the phylogenetic structure tended to cluster with increasing latitude and longitude; 2) for NRI, latitude was closer related than longitude,while for NTI, longitude was closer related than latitude, though they both not significantly relate to NTI.The phylogenetic structure tended towards overdispersion in the southern HDMR, with good climate conditions of higher mean annual temperature and more mean annual precipitation. In contrast, with harsh climate conditions of lower mean annual temperature and less mean annual precipitation, the increasing environmental stress led to phylogenetic clustering in the northern HDMR. The results highlighted that in the alpine region of HDMR, environmental filters and geographical isolation had a great effect on the latitudinal and longitudinal alpine species distribution, respectively.展开更多
Previous attempts to elucidate the drivers of speciation mechanisms and spatial distribution patterns of biodiversity in mountain regions have treated different floras within a single geological region as one flora,ig...Previous attempts to elucidate the drivers of speciation mechanisms and spatial distribution patterns of biodiversity in mountain regions have treated different floras within a single geological region as one flora,ignoring the potential contributions of high habitat/ecosystem heterogeneity.Furthermore,current conservation strategies largely focus on forest ecosystems and/or specific flagship species,ignoring marginal ecosystems,leaving species in these ecosystems at risk.Here,we compared the spatial patterns of biodiversity and the potential drivers of these patterns in the river valley and subnival ecosystems of the Hengduan Mountains region(HDM)in southwestern China.Specifically,we compared spatial patterns of diversity,endemism,and threatened species in these ecosystems based on both traditional measurements and recent phylogenetic approaches.We then examined how those patterns were related to environmental factors and human activity in these same regions.We found that the middle-southern HDM supports the highest diversity and endemism for the river valley and subnival ecosystems;however,the distribution patterns of neo-and paleo-endemism in these two ecosystems differ.Regression models indicate that habitat diversity and paleo-climatic fluctuation are important drivers of diversity and endemism for these two ecosystems.Temperature and precipitation,however,showed different influences on the spatial patterns in different ecosystems.Categorical analysis of neo-and paleoendemism(CANAPE)indicated that most endemism centers are not covered by current nature reserves.Moreover,the intensity of human activity is highest in the southern and southeastern HDM,which coincides with the distribution patterns of diversity,mixed-endemism and high-priority(and threatened)species.These findings suggest that different floras within a single geographic/floristic region respond differently to environmental factors and show different spatial phylogenetic patterns.We,therefore,recommend that future research into the drivers of biodiversity consider the contributions of various ecosystem types within a single geological region.This study also provides a theoretical basis for protecting habitat diversity.Our work confirms that current conservation efforts are insufficient to protect ecosystem diversity in the river valley and subnival ecosystems of the Hengduan Mountains.Therefore,we recommend the establishment of nature reserves in the regions identified in this study;furthermore,we strongly recommend improving current and establishing new management policies for biodiversity conservation in this region.展开更多
Yunnan,located in southwestern China,harbors more than 19,000 higher plants,which represents the highest plant diversity in the country.However,plant diversity in Yunnan faces enormous threats today,including habitat ...Yunnan,located in southwestern China,harbors more than 19,000 higher plants,which represents the highest plant diversity in the country.However,plant diversity in Yunnan faces enormous threats today,including habitat destruction and fragmentation,environmental pollution,and over-exploitation of natural resources.Despite recent efforts to protect biodiversity,there are still thousands of threatened species,some of which have become extinct.We analyzed available data to gain a greater understanding of plant diversity and the status of plant conservation in Yunnan.We found that southern,southeastern,and northwestern Yunnan are hotspots of total species,endemic species,specimens,new species and threatened species,whereas southeastern Yunnan is a hotspot for plant species with extremely small populations.Moreover,we found that there are still conservation gaps and poorly protected areas in central,eastern,and northeastern Yunnan.We conclude that conservation of plant diversity in Yunnan requires modern field investigation,systematic research,the development of comprehensive databases,and government support.We recommend that conservationists pay more attention to building and improving functional protection systems and popularizing science.展开更多
Toxicodendron is a genus in the Rhus complex of Anacardiaceae with a disjunct distribution between eastern Asia and North America, extending to southeastern Asia and the neotropics. Nuclear (internal transcribed spac...Toxicodendron is a genus in the Rhus complex of Anacardiaceae with a disjunct distribution between eastern Asia and North America, extending to southeastern Asia and the neotropics. Nuclear (internal transcribed spacer, external transcribed spacer, and NIA-i3) and chloroplast (ndhF and trnL-F) sequences were used to construct phylogenetic relationships of Toxicodendron. Phylogenetic analysis of these data strongly support Toxieodendron as a monophyletic group distinct from other genera of the Rhus complex, and the phylogeny does not fully corroborate classification at the sectional level. Two temperate disjunct lineages were detected, one from section Toxicodendron and the other between the eastern North American Toxicodendron vernix and the eastern Asian Toxicodendron vernieifluum. Their divergence times were estimated to be 13.46 (7.95-19.42) and 7.53 (2.76-12.86) mya, respectively. The disjunction between section Griffithii (taxa from warm temperate to tropical Asia) and Toxieodendron striatum (from the neotropics) was supported and their divergence time was estimated to be 20.84 (11.1 6-30.52) mya in the early Miocene. Our biogeographic results and the paleontological data support the Bering land bridge as the most likely route to explain the temperate disjunctions, yet the tropical disjunction in Toxicodendron seems to be best explained by the North Atlantic land bridge hypothesis.展开更多
The Hengduan Mountains region of south-west China is a noted biodiversity,hotspot, but the geographic origins and historical assembly of its rich endemic flora, including the sky-island species ofSolms-laubachia Musch...The Hengduan Mountains region of south-west China is a noted biodiversity,hotspot, but the geographic origins and historical assembly of its rich endemic flora, including the sky-island species ofSolms-laubachia Muschl. (Brassicaceae), have been little studied. Previous molecular studies on the phylogeny of Solms-laubachia showed it to be paraphyletic, leading to considerable expansion not only of its taxonomic limits, but also its geographic range, with the inclusion of taxa from outside the Hengduan region. However, these studies provided little resolution of interspecific relationships, preventing inferences about historical biogeography within the clade. In the present study, new sequence data from two nuclear genes (LEAFY and G3pdh) and two chloroplast intergenic spacers (petN-psbM and psbM-trnD) were combined with existing markers to increase phylogenetic signals. Phaeonychium villosum (Maxim.) Al-Shehbaz was found to be nested within Solms-laubachia s.l. In general, phylogenetic relationships appear to be a good predictor of geography, with the Hengduan Mountain endemics embedded in a paraphyletic grade of species from the western Himalayas and central Asia, but they also imply morphological homoplasy, lncongruence was detected between the nuclear and chloroplast gene trees, perhaps resulting from incomplete lineage sorting of ancestral polymorphisms. The crown age ofSolms-laubachia s.l. was estimated to be approximately 1.42-3.68 mya, using Bayesian relaxed molecular clock analysis. Historical biogeographic analysis using a parametric dispersalextinction-cladogenesis model inferred central Asia and the western Himalayas as most probable ancestral range of Solms-laubachia s.l., and estimated higher rates of eastward expansion than westward during the diversification of descendant lineages. In summary, our results suggest that Solms-laubachia s.l. originated during the Pliocene in central Asia, and subsequently migrated eastward into the Hengduan Mountains, colonizing sky-island, alpine scree-slope habitats that may have provided novel ecological opportunity and accelerated speciation, ultimately establishing this region as the present center of diversity of the genus.展开更多
The species composition of regional plant assemblages can in large part be explained by a long history of biogeographical and evolutionary events. Traditional attempts of floristic studies typically focus on the analy...The species composition of regional plant assemblages can in large part be explained by a long history of biogeographical and evolutionary events. Traditional attempts of floristic studies typically focus on the analyses of taxonomic composition, often ignoring the rich context that evolutionary history can provide.In 2014, Swenson and Uma~na introduced the term ‘phylofloristics' to define a phylogenetically enabled analysis of the species composition of regional floras. Integrating phylogenetic information into traditional floristic analysis can provide a promising way to explore the ecological, biogeographic, and evolutionary processes that drive plant assemblies at multiple spatial scales. In this review, we summarize the current progress on the phylogenetic structure, spatial phylogenetic pattern, origin and diversification, phylogenetic regionalization of floristic assemblages, and application of phylogenetic information in biodiversity conservation. These summaries highlight the importance of incorporating phylogenetic information to improve our understanding of floristic assembly from an evolutionary perspective. The review ends with a brief outlook on future challenges for phylofloristic studies,including generating a highly resolved species-level phylogenetic tree, compiling detailed and refined information regarding the geographic distribution of all plant life, extracting trait information from publications and herbarium specimens, and developing technological and methodological approaches for big data analysis.展开更多
Cushion species occur in nearly all alpine environments worldwide. In past decades, the adaptive and ecosystem-engineering roles of such highly specialized life forms have been well studied. However, the adaptive stra...Cushion species occur in nearly all alpine environments worldwide. In past decades, the adaptive and ecosystem-engineering roles of such highly specialized life forms have been well studied. However, the adaptive strategies responsible for cushion species reproductive success and maintenance in severe alpine habitats remain largely unclear. In this study, we reviewed the current understanding of reproductive strategies and population persistence in alpine cushion species. We then present a preliminary case study on the sexual reproduction of Arenaria polytrichoides(Caryophyllaceae), a typical cushion species inhabiting high elevations of the Himalaya Hengduan Mountains, which is a hotspot for diversification of cushion species. Finally, we highlight the limitations of our current understanding of alpine cushion species reproduction and propose future directions for study.展开更多
Cytological characters of four species in Syncalathium (Asteraceae: Lactuceae), a small genus with six identified species endemic to alpine scree of the Sino-Himalayan region, are surveyed in this report. Three spe...Cytological characters of four species in Syncalathium (Asteraceae: Lactuceae), a small genus with six identified species endemic to alpine scree of the Sino-Himalayan region, are surveyed in this report. Three species (Syncalathiumpilosum, Syncalathium chrysocephalum, and Syncalathium disciforme) are examined for the first time. Combined with our previous counts, five species have been cytologically investigated from the genus and the results indicated that all species are diploid with the basic somatic chromosome number of x=8. The karyotype asymmetry of Syncalathium souliei is 2A, distinct from the other four species of 1A, and the remaining species are divided into two subgroups with different karyotypes, consistent with their morphological features. The significance of the cytological evolution of Syncalathium is briefly discussed.展开更多
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0502 to H.S.)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA20050203 to H.S.)+3 种基金the Yunnan Applied Basic Research Project(202001AT070060 to J.G.C.)the National Natural Science Foundation of China(31271552 to J.G.C.)the CAS“Light of West China”Program(J.G.C.)the Young Academic and Technical Leader Raising Foundation of Yunnan Province(202205AC160053 to J.G.C.)。
文摘When benefiting other beneficiaries,cushion plants may reciprocally receive feedback effects.The feedback effects on different sex morphs,however,remains unclear.In this study,taking the gynodioecious Arenaria polytrichiodes as a model species,we aimed to assess the sex-specific facilitation intensity of cushion plant by measuring the beneficiary cover ratio,and to assess the potential costs in cushion reproductive functions by measuring the flower and fruit cover ratios.The total beneficiary cover ratio was similar between females and hermaphrodites.Females produced much less flowers but more fruits than hermaphrodites.These results suggested that females and hermaphrodites possess similar facilitation intensity,and female cushion A.polytrichoides may allocate more resources saved from pollen production to seed production,while hermaphrodites possibly allocate more resources to pollen production hence reducing seed production.The surface areas covered by beneficiaries produced less flowers and fruits than areas without beneficiaries.In addition,strong negative correlations between beneficiary cover and flower cover were detected for both females and hermaphrodites,but the correlation strength were similar for these two sex morphs.However,the correlation between beneficiary cover and fruit cover was only significantly negative for females,suggesting that beneficiary plants negatively affect fruit reproduction of females while have neutral effects on hermaphrodites.All the results suggest that to facilitate other beneficiaries can induce reproductive costs on cushion A.polytrichoides,with females possibly suffering greater cost than hermaphrodites.Such differentiation in reproductive costs between sex morphs,in long-term perspective,may imply sex imbalance in population dynamics.
基金supported by the Key Projects of the Joint Fund of the National Natural Science Foundation of China (U23A20149)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA20050203)+3 种基金the Second Tibetan Plateau Scientific Expedition and Research program (2019QZKK0502)the National Natural Science Foundation of China (32371702, 32071669 and 31770249)the West Light Foundation of the Chinese Academy of Sciences Interdisciplinary Innovation Team Program (xbzg-zdsys202319)the Ten-thousand Talents Program of Yunnan Province (YNWR-QNBJ-2018-208)。
文摘Sexual systems play important roles in angiosperm evolution and exhibit substantial variations among different floras. Thus, studying their evolution in a whole flora is crucial for understanding the formation and maintenance of plant biodiversity and predicting its responses to environmental change. In this study, we determined the patterns of plant sexual systems and their associations with geographic elements and various life-history traits in dry-hot valley region of southwestern China, an extremely vulnerable ecosystem. Of the 3166 angiosperm species recorded in this area, 74.5% were hermaphroditic,13.5% were monoecious and 12% were dioecious, showing a high incidence of diclinous species. Diclinous species were strongly associated with tropical elements, whereas hermaphroditic species were strongly associated with temperate and cosmopolitan elements. We also found that hermaphroditism was strongly associated with showy floral displays, specialist entomophily, dry fruits and herbaceous plants.Dioecy was strongly associated with inconspicuous, pale-colored flowers, generalist entomophily, fleshy fruits, and woody plants, whereas monoecy was strongly associated with inconspicuous, pale-colored flowers, anemophily, dry fruits, and herbaceous plants. In addition, hermaphroditic species with generalist entomophily tended to flower in the dry season, whereas diclinous species with specialist entomophily tended to flower in the rainy season. However, independent of sexual systems, plants that produce dry fruits tended to flower in the rainy season and set fruits in the dry season, but the opposite pattern was found for fleshy fruit-producing plants. Our results suggest that in the dry-hot valleys, plant sexual systems are associated with geographic elements as well as various life-history traits that are sensitive to environmental change.
基金supported by grants from the Key Projects of the Joint Fund of the National Natural Science Foundation of China (U23A20149)the Second Tibetan Plateau Scientific Expedition and Research (STEP) program (2019QZKK0502)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA20050203)International Partnership Program of the Chinese Academy of Sciences (151853KYSB20180009)the state research project Taxonomic revision of polymorphic plant families of the flora of Uzbekistan’ (FZ-20200929321)the State Programs for the years 2021-2025 ’Grid mapping of the flora of Uzbekistan’ and the ’Tree of life:monocots of Uzbekistan’ of the Institute of Botany of the Academy of Sciences of the Republic of Uzbekistan
文摘Eremurus was described at the beginning of the 19th century.However,due to limited sampling and the small number of gene markers to date,its phylogeny and evolution are largely unknown.In this study,we analyzed plastomes from 27 species belonging to 2 subgenera and 3 sections of Eremurus,which are found in Central Asia(its center of diversity)and China.We also analyzed nuclear DNA ITS of 33 species,encompassing all subgenera and sections of the genus in Central Asia,southwest Asia and China.Our findings revealed that the genus was monophyletic,although both subgenera Eremurus and Henningia were found to be paraphyletic.Both plastome and nrDNA-based phylogenetic trees had three clades that did not reflect the current taxonomy of the genus.Our biogeographical and time-calibrated trees suggest that Eremurus originated in the ancient Tethyan area in the second half of the Eocene.Diversification of Eremurus occurred from the early Oligocene to the late Miocene.Paratethys Sea retreat and several orogenetic events,such as the progressive uplift of the Qinghai-Tibet Plateau and surrounding mountain belts(Altai,Pamir,Tian Shan),caused serious topographic and climate(aridification)changes in Central Asia that may have triggered a split of clades and speciation.In this transformed Central Asia,speciation proceeded rapidly driven mainly by vicariance caused by numerous mountain chains and specialization to a variety of climatic,topographic and soil conditions that exist in this region.
文摘Brain–computer interface (BCI) systems, such as the P300 speller, enable patients to express intentions withoutnecessitating extensive training.However, the complexity of operational instructions and the slow pace of characterspelling pose challenges for some patients. In this paper, an image segmentation P300 selector based on YOLOv7-mask and DeepSORT is proposed. The proposed system utilizes a camera to capture real-world objects forclassification and tracking. By applying predefined stimulation rules and object-specificmasks, the proposed systemtriggers stimuli associated with the objects displayed on the screen, inducing the generation of P300 signals in thepatient’s brain. Its video processing mechanism enables the system to identify the target the patient is focusing oneven if the object is partially obscured, overlapped, moving, or changing in number. The system alters the target’scolor display, thereby conveying the patient’s intentions to caregivers. The data analysis revealed that the selfrecognitionaccuracy of the subjects using this method was between 92% and 100%, and the cross-subject P300recognition precision was 81.9%–92.1%. This means that simple instructions such as “Do not worry, just focuson what you desire” effectively discerned the patient’s intentions using the Image Segmentation-P300 selector. Thisapproach provides cost-effective support and allows patients with communication difficulties to easily express theirneeds.
基金funded by the West Light Foundation of The Chinese Academy of Sciencesnational youth talent support programYunnan youth talents plan(YNWR-QNBJ-2018-183 to Y.N.)。
文摘Flower constancy describes the phenomenon that pollinators tend to successively visit flowers of a single species during foraging,reducing reproductive interference in natural communities.The extent of flower constancy is largely determined by the floral traits of co-flowering species.Both higher inter-specific and lower intraspecific differences of floral traits should contribute to a higher level of flower constancy.However,previous studies mainly focused on interspecific difference,and the intraspecific variation(consistency)of floral traits received much less attention.We hypothesise that selection may favour lower intraspecific floral trait variation in communities composed of multiple co-flowering congeners.We investigated the floral colour variation of three focal Pedicularis species that share pollinators in 19communities composed of either single or multiple Pedicularis species.Colour was quantified using image-based colour analysis as perceived by pollinators.We found that most of the intrapopulation floral colour variation was below the colour discrimination threshold of bumblebees,implying strongly constrained by the visual selection by pollinators.Contrary to the hypothesis,there is no significant difference in intraspecific floral colour variation between different community contexts.It may be due to the relatively large interspecific floral colour differences of most co-flowering species.The influence of community context on intraspecific variation may be reflected in floral traits other than colours.
基金supported by Medical Scientific Research Foundation of Chongqing of China(2022MSXM048).
文摘Background:Cholangiocarcinoma(CCA)is highly malignant and has a poor prognosis has a high malignant degree and poor prognosis.The purpose of this study is to develop a new prognostic model based on genes related to the tumor microenvironment(TME).Methods:Derived from the discerned differentially expressed genes within The Cancer Genome Atlas(TCGA)dataset,this investigation employed the methodology of weighted gene co-expression network analysis(WGCNA)to ascertain gene co-expressed modules intricately linked to the Tumor Microenvironment(TME)among Cholangiocarcinoma(CCA)patients.The genes associated with prognosis,as identified through Cox regression analysis,were employed in the formulation of a predictive model.This model underwent validation,leading to the development of a risk score formula and nomogram.Concurrently,we validated the model’s reliability using data from CCA patients in the Gene Expression Omnibus(GEO)database(accession:GSE107943).Results:6139 DEGs were divided into 10 co-expressed gene modules using WGCNA.Among these,two modules(blue module with 832 genes and brown module with 1379 genes)showed high correlation with the TME.Five prognostic genes(BNIP3,COL4A3,SPRED3,CEBPB,PLOD2)were identified through Cox regression analysis,and a prognostic model and risk score formula were developed based on these genes.Risk score formula:Risk score=BNIP3×1.70520-COL4A3×2.39815+SPRED3×1.17936+CEBPB×0.40456+PLOD2×0.24785.Kaplan-Meier survival analysis revealed that the survival probabilities of the low-risk group were significantly higher than those of the high-risk group.Furthermore,the related evaluation indexes suggested that the model exhibited strong predictive ability.Conclusion:The prognostic model,based on five TME-related genes(BNIP3,COL4A3,SPRED3,CEBPB,PLOD2),could accurately assess the prognosis of CCA patients to aid in guiding clinical decisions.
基金This work was supported by the Second Tibetan Plateau Scientific Expedition and Research program(2019QZKK0502)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA20050203)+3 种基金the National Natural Science Foundation of China(31770249 and 32071669)the Young Academic and Technical Leader Raising Foundation of Yunnan Province(2017HB062)the Ten-thousand Talents Program of Yunnan Province(YNWR-QNBJ2018-208)the Yunnan Innovation Team Project(202305AS350004).
文摘Plants have long been thought to be less dependent on pollinators for seed production at higher elevations due to adverse pollination environments.However,recent research has yet to consistently support the generality of this expectation.In this study,we asked whether pollinator dependence decreases along an elevational gradient and how it varies with various reproductive traits.To answer these questions,we quantified pollinator-plant associations and various reproductive traits for 112 flowering plants spanning a large elevational gradient(990-4260 m a.s.l.)in the Qinghai-Tibet Plateau.We found that flowering plants in the Qinghai-Tibet Plateau region are highly dependent on pollinators for seed production(76.2%of seed production was contributed by animal pollinators and 44.6%of plants would produce no seed without pollinator visitation).Contrary to our expectation,there was no significant elevational gradient in pollinator dependence index.Although the pollinator dependence index was not significantly correlated with pollen limitation,flower size,floral longevity,or reward type,it was correlated with compatibility status and flowering time.These findings indicate that pollinator dependence does not decrease along an elevational gradient in the Qinghai-Tibet Plateau.Our study also highlights the severe vulnerability of flowering plant seed production to pollinator declines under global change in the Qinghai-Tibet Plateau region,particularly for early-flowering or self-incompatible plants growing at higher elevations(e.g.,subnival belt).
基金funded by the Key Projects of the Joint Fund of the National Natural Science Foundation of China(U1802232)the national youth talent support program+2 种基金CAS"Light of West China"ProgramYunnan youth talent support program(YNWR-QNBJ-2018-183 to Y.N.)Vietnam Academy of Science and Technology(UQDTCB.06/22-23)。
文摘Brandisia is a shrubby genus of about eight species distributed basically in East Asian evergreen broadleaved forests(EBLFs),with distribution centers in the karst regions of Yunnan,Guizhou,and Guangxi in southwestern China.Based on the hemiparasitic and more or less liana habits of this genus,we hypothesized that its evolution and distribution were shaped by the development of EBLFs there.To test our hypothesis,the most comprehensive phylogenies of Brandisia hitherto were constructed based on plastome and nuclear loci(nrDNA,PHYA and PHYB);then divergence time and ancestral areas were inferred using the combined nuclear loci dataset.Phylogenetic analyses reconfirmed that Brandisia is a member of Orobanchaceae,with unstable placements caused by nuclear-plastid incongruences.Within Brandisia,three major clades were well supported,corresponding to the three subgenera based on morphology.Brandisia was inferred to have originated in the early Oligocene(32.69 Mya)in the Eastern Himalayas-SW China,followed by diversification in the early Miocene(19.45 Mya)in karst EBLFs.The differentiation dates of Brandisia were consistent with the origin of keystone species of EBLFs in this region(e.g.,Fagaceae,Lauraceae,Theaceae,and Magnoliaceae)and the colonization of other characteristic groups(e.g.,Gesneriaceae and Mahonia).These findings indicate that the distribution and evolution of Brandisia were facilitated by the rise of the karst EBLFs in East Asia.In addition,the woody and parasitic habits,and pollination characteristics of Brandisia may also be the important factors affecting its speciation and dispersal.
基金This work was supported by grants from the National Natural Science Foundation of China(U2003122)the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0502).Sequencing service was provided by Bioyi Biotechnology Co.,Ltd.Wuhan,China。
文摘Dear Editor,Understanding the evolution and survival mechanisms of endangered wild medicinal herbs is crucial for their cultivation,utilization,and conservation.The snow lotus species Saussurea involucrata(Kar.&Kir.)Sch.Bip.(2n=32)(i.e.the well-known Tianshan snow lotus)which belongs to the eudicot family Asteraceae,is a famous traditional Chinese medicinal herb having anti-inflammatory.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0502)the Yunnan Applied Basic Research Project(202001AT070060)+2 种基金the National Natural Science Foundation of China(31271552)the CAS“Light of West China”Program,the Young Academic and Technical Leader Raising Foundation of Yunnan Province(202205AC160053)the Yunnan Innovation team project(202305AS350004)。
文摘Foundational cushion plants can re-organize community structures and sustain a prominent proportion of alpine biodiversity,but they are sensitive to climate change.The loss of cushion species can have broad consequences for associated biota.The potential plant community changes with the population dynamics of cushion plants remain,however,unclear.Using eight plant communities along a climatic and community successional gradient,we assessed cushion population dynamics,the underlying ecological constraints and hence associated plant community changes in alpine communities dominated by the foundational cushion plant Arenaria polytrichoides.The population dynamics of Arenaria are attributed to ecological constraints at a series of life history stages.Reproductive functions are constrained by increasing associated beneficiary plants;subsequent seedling establishment is constrained by temperature,water and light availability,extreme climate events,and interspecific competition;strong competitive exclusion may accelerate mortality and degeneration of cushion populations.Along with cushion dynamics,species composition,abundance and community structure gradually change.Once cushion plants completely degenerate,previously cushion-dominated communities shift to relatively stable communities that are overwhelmingly dominated by sedges.Climate warming may accelerate the degeneration process of A.polytrichoides.Degeneration of this foundational cushion plant will possibly induce massive changes in alpine plant communities and hence ecosystem functions in alpine ecosystems.The assessment of the population dynamics of foundation species is critical for an effective conservation of alpine biodiversity.
文摘Eighty years ago, a botanical institute called"the Yunnan Provincial Institute of Agricultural and Forestry Botany"was jointly founded by the Jingsheng Biology Institute and the Yunnan State Department of Education in Kunming. At that time, the Heilong Dragon Park became the institute's home (Fig. 1) and the research conducted there mostly focused on taxonomy and economical botany. When the institute came under the auspices of the Chinese Academy of Science, it still had fewer than 20 staff members.
基金funded by the Major Program of the National Natural Science Foundation of China (31590823 to H.S.),the National Natural Science Foundation of China(31370004 and 31570213 to J.W.Z.,31700165 to T.D.)the National Key R&D Program of China (2017YFC0505200 to H.S.)CAS ‘Light of West China’ Program to T.D.
文摘1.Introduction The Hengduan Mountains region(HDM)in southwest China,one of the earth's 34 biodiversity hotspots,is characterized by its unique geology,dramatic topography,a climate where snow and below freezing temperatures can occur on any day of the year,by its location at elevations averaging between(1400e)2000 and4500(e5300)meters above sea level(m a.s.l.),and by one of
基金supported by Major Program of National Natural Science Foundation of China grant no. 31590823 to Hang Sunthe National Natural Science Foundation of China (NSFC) Grant No. 31560063Key Disciplines (Ecology) Project of Yunnan Education Department
文摘To detect the horizontal pattern of phylogenetic structure shown by alpine plants, we measured phylogenetic structure using net related index(NRI) and net nearest taxon index(NTI), and analyzed the phylogenetic structure patterns of alpine plants along longitude, latitude and environmental gradients in the Hengduan Mountains Region(HDMR). Our results show that: 1) the phylogenetic structure tended to cluster with increasing latitude and longitude; 2) for NRI, latitude was closer related than longitude,while for NTI, longitude was closer related than latitude, though they both not significantly relate to NTI.The phylogenetic structure tended towards overdispersion in the southern HDMR, with good climate conditions of higher mean annual temperature and more mean annual precipitation. In contrast, with harsh climate conditions of lower mean annual temperature and less mean annual precipitation, the increasing environmental stress led to phylogenetic clustering in the northern HDMR. The results highlighted that in the alpine region of HDMR, environmental filters and geographical isolation had a great effect on the latitudinal and longitudinal alpine species distribution, respectively.
基金This study was supported equally by the National Key R&D Program of China(2017YFC0505200 to H Sun)the Major Program of the National Natural Science Foundation of China(31590823 to H Sun)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA20050203 to H Sun)USDA National Institute of Food and Agriculture(McIntire Stennis#101869 to DS).
文摘Previous attempts to elucidate the drivers of speciation mechanisms and spatial distribution patterns of biodiversity in mountain regions have treated different floras within a single geological region as one flora,ignoring the potential contributions of high habitat/ecosystem heterogeneity.Furthermore,current conservation strategies largely focus on forest ecosystems and/or specific flagship species,ignoring marginal ecosystems,leaving species in these ecosystems at risk.Here,we compared the spatial patterns of biodiversity and the potential drivers of these patterns in the river valley and subnival ecosystems of the Hengduan Mountains region(HDM)in southwestern China.Specifically,we compared spatial patterns of diversity,endemism,and threatened species in these ecosystems based on both traditional measurements and recent phylogenetic approaches.We then examined how those patterns were related to environmental factors and human activity in these same regions.We found that the middle-southern HDM supports the highest diversity and endemism for the river valley and subnival ecosystems;however,the distribution patterns of neo-and paleo-endemism in these two ecosystems differ.Regression models indicate that habitat diversity and paleo-climatic fluctuation are important drivers of diversity and endemism for these two ecosystems.Temperature and precipitation,however,showed different influences on the spatial patterns in different ecosystems.Categorical analysis of neo-and paleoendemism(CANAPE)indicated that most endemism centers are not covered by current nature reserves.Moreover,the intensity of human activity is highest in the southern and southeastern HDM,which coincides with the distribution patterns of diversity,mixed-endemism and high-priority(and threatened)species.These findings suggest that different floras within a single geographic/floristic region respond differently to environmental factors and show different spatial phylogenetic patterns.We,therefore,recommend that future research into the drivers of biodiversity consider the contributions of various ecosystem types within a single geological region.This study also provides a theoretical basis for protecting habitat diversity.Our work confirms that current conservation efforts are insufficient to protect ecosystem diversity in the river valley and subnival ecosystems of the Hengduan Mountains.Therefore,we recommend the establishment of nature reserves in the regions identified in this study;furthermore,we strongly recommend improving current and establishing new management policies for biodiversity conservation in this region.
基金the National Key R&D Program of China(2017YFC0505200)the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0502)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(XDA20050203)the Key Projects of the Joint Fund of the National Natural Science Foundation of China(U1802232).
文摘Yunnan,located in southwestern China,harbors more than 19,000 higher plants,which represents the highest plant diversity in the country.However,plant diversity in Yunnan faces enormous threats today,including habitat destruction and fragmentation,environmental pollution,and over-exploitation of natural resources.Despite recent efforts to protect biodiversity,there are still thousands of threatened species,some of which have become extinct.We analyzed available data to gain a greater understanding of plant diversity and the status of plant conservation in Yunnan.We found that southern,southeastern,and northwestern Yunnan are hotspots of total species,endemic species,specimens,new species and threatened species,whereas southeastern Yunnan is a hotspot for plant species with extremely small populations.Moreover,we found that there are still conservation gaps and poorly protected areas in central,eastern,and northeastern Yunnan.We conclude that conservation of plant diversity in Yunnan requires modern field investigation,systematic research,the development of comprehensive databases,and government support.We recommend that conservationists pay more attention to building and improving functional protection systems and popularizing science.
基金supported bygrants from the National Basic Research Program of China (973 Program,grant no. 2007CB411601)the National Natural Science Foundation of China (grant nos.30625004 and 40771073 to H. Sun)+2 种基金the Yunnan Natural Science Foundation (grant no. 2008CC013)the John D. and Catherine T. MacArthur Foundation (to J.Wen)supported by the Laboratory of Analytical Biology of the National Museum of Natural History,Smithsonian Institution,Washington DC,USA
文摘Toxicodendron is a genus in the Rhus complex of Anacardiaceae with a disjunct distribution between eastern Asia and North America, extending to southeastern Asia and the neotropics. Nuclear (internal transcribed spacer, external transcribed spacer, and NIA-i3) and chloroplast (ndhF and trnL-F) sequences were used to construct phylogenetic relationships of Toxicodendron. Phylogenetic analysis of these data strongly support Toxieodendron as a monophyletic group distinct from other genera of the Rhus complex, and the phylogeny does not fully corroborate classification at the sectional level. Two temperate disjunct lineages were detected, one from section Toxicodendron and the other between the eastern North American Toxicodendron vernix and the eastern Asian Toxicodendron vernieifluum. Their divergence times were estimated to be 13.46 (7.95-19.42) and 7.53 (2.76-12.86) mya, respectively. The disjunction between section Griffithii (taxa from warm temperate to tropical Asia) and Toxieodendron striatum (from the neotropics) was supported and their divergence time was estimated to be 20.84 (11.1 6-30.52) mya in the early Miocene. Our biogeographic results and the paleontological data support the Bering land bridge as the most likely route to explain the temperate disjunctions, yet the tropical disjunction in Toxicodendron seems to be best explained by the North Atlantic land bridge hypothesis.
基金supported by the Chinese National Natural Science Foundation (grants no.30625004,40771073 to HS)the Yunnan Natural Science Foundation (2008CC013 to HS)+4 种基金the US National Science Foundation (grant no. DEB-0321846,to DEB)the John D. and Catherine T. MacArthur Foundation (grant to JW,RR,and GM)the Innovation Project of the Chinese Academy of Sciences (KSCX2-YW-Z-030)a Mercer Fellowship from the Arnold Arboretum (to JPY)supported by the National Geographic Society (grant no.7405-03)
文摘The Hengduan Mountains region of south-west China is a noted biodiversity,hotspot, but the geographic origins and historical assembly of its rich endemic flora, including the sky-island species ofSolms-laubachia Muschl. (Brassicaceae), have been little studied. Previous molecular studies on the phylogeny of Solms-laubachia showed it to be paraphyletic, leading to considerable expansion not only of its taxonomic limits, but also its geographic range, with the inclusion of taxa from outside the Hengduan region. However, these studies provided little resolution of interspecific relationships, preventing inferences about historical biogeography within the clade. In the present study, new sequence data from two nuclear genes (LEAFY and G3pdh) and two chloroplast intergenic spacers (petN-psbM and psbM-trnD) were combined with existing markers to increase phylogenetic signals. Phaeonychium villosum (Maxim.) Al-Shehbaz was found to be nested within Solms-laubachia s.l. In general, phylogenetic relationships appear to be a good predictor of geography, with the Hengduan Mountain endemics embedded in a paraphyletic grade of species from the western Himalayas and central Asia, but they also imply morphological homoplasy, lncongruence was detected between the nuclear and chloroplast gene trees, perhaps resulting from incomplete lineage sorting of ancestral polymorphisms. The crown age ofSolms-laubachia s.l. was estimated to be approximately 1.42-3.68 mya, using Bayesian relaxed molecular clock analysis. Historical biogeographic analysis using a parametric dispersalextinction-cladogenesis model inferred central Asia and the western Himalayas as most probable ancestral range of Solms-laubachia s.l., and estimated higher rates of eastward expansion than westward during the diversification of descendant lineages. In summary, our results suggest that Solms-laubachia s.l. originated during the Pliocene in central Asia, and subsequently migrated eastward into the Hengduan Mountains, colonizing sky-island, alpine scree-slope habitats that may have provided novel ecological opportunity and accelerated speciation, ultimately establishing this region as the present center of diversity of the genus.
基金supported by the National Natural Science Foundation of China (grant no. 31570212, 31770228, 31370243)the Talent Project of Yunnan (grant no. 2015HB092)
文摘The species composition of regional plant assemblages can in large part be explained by a long history of biogeographical and evolutionary events. Traditional attempts of floristic studies typically focus on the analyses of taxonomic composition, often ignoring the rich context that evolutionary history can provide.In 2014, Swenson and Uma~na introduced the term ‘phylofloristics' to define a phylogenetically enabled analysis of the species composition of regional floras. Integrating phylogenetic information into traditional floristic analysis can provide a promising way to explore the ecological, biogeographic, and evolutionary processes that drive plant assemblies at multiple spatial scales. In this review, we summarize the current progress on the phylogenetic structure, spatial phylogenetic pattern, origin and diversification, phylogenetic regionalization of floristic assemblages, and application of phylogenetic information in biodiversity conservation. These summaries highlight the importance of incorporating phylogenetic information to improve our understanding of floristic assembly from an evolutionary perspective. The review ends with a brief outlook on future challenges for phylofloristic studies,including generating a highly resolved species-level phylogenetic tree, compiling detailed and refined information regarding the geographic distribution of all plant life, extracting trait information from publications and herbarium specimens, and developing technological and methodological approaches for big data analysis.
基金supported by grants from the National Key Research and Development Program of China (grant no. 2017YFC0505200)the Major Program of National Natural Science Foundation of China (grant no. 31590823) to H Sunthe Natural Science Foundation of China (Grant no. 31500185 to JG Chen, 31470321 to Y Yang)
文摘Cushion species occur in nearly all alpine environments worldwide. In past decades, the adaptive and ecosystem-engineering roles of such highly specialized life forms have been well studied. However, the adaptive strategies responsible for cushion species reproductive success and maintenance in severe alpine habitats remain largely unclear. In this study, we reviewed the current understanding of reproductive strategies and population persistence in alpine cushion species. We then present a preliminary case study on the sexual reproduction of Arenaria polytrichoides(Caryophyllaceae), a typical cushion species inhabiting high elevations of the Himalaya Hengduan Mountains, which is a hotspot for diversification of cushion species. Finally, we highlight the limitations of our current understanding of alpine cushion species reproduction and propose future directions for study.
基金supported bygrants-in-aid from the National Natural Science Foundation of China (NSFC 30625004, 40771073 to HSUN, and 30770167 to Z-L NIE)the Yunnan Natural Science Foundation (2008CC013 to HSUN)the National Science Foundation (DEB-0321846 to DEBOUFFORD)
文摘Cytological characters of four species in Syncalathium (Asteraceae: Lactuceae), a small genus with six identified species endemic to alpine scree of the Sino-Himalayan region, are surveyed in this report. Three species (Syncalathiumpilosum, Syncalathium chrysocephalum, and Syncalathium disciforme) are examined for the first time. Combined with our previous counts, five species have been cytologically investigated from the genus and the results indicated that all species are diploid with the basic somatic chromosome number of x=8. The karyotype asymmetry of Syncalathium souliei is 2A, distinct from the other four species of 1A, and the remaining species are divided into two subgroups with different karyotypes, consistent with their morphological features. The significance of the cytological evolution of Syncalathium is briefly discussed.