Global warming increases the vulnerability of plants, especially alpine herbaceous species, to local extinction. In this study, we collected species distribution information from herbarium specimens for ten selected C...Global warming increases the vulnerability of plants, especially alpine herbaceous species, to local extinction. In this study, we collected species distribution information from herbarium specimens for ten selected Cyananthus and Primula alpine species endemic to the Himalaya-Hengduan Mountains(HHM).Combined with climate data from WorldClim, we used Maximum Entropy Modeling(MaxEnt) to project distributional changes from the current time period to 2070. Our predictions indicate that, under a wide range of climate change scenarios, the distributions of all species will shift upward in elevation and northward in latitude; furthermore, under these scenarios, species will expand the size of their range. For the majority of the species in this study, habitats are available to mitigate upward and northward shifts that are projected to be induced by changing climate. If current climate projections, however, increase in magnitude or continue to increase past our projection dates, suitable habitat for future occupation by alpine species will be limited as we predict range contraction or less range expansion for some of the species under more intensified climate scenarios. Our study not only underscores the value of herbarium source information for future climate model projections but also suggests that future studies on the effects of climate change on alpine species should include additional biotic and abiotic factors to provide greater resolution of the local dynamics associated with species persistence under a warming climate.展开更多
Nervonic acid(NA,cis-15-tetracosenoic acid)is a very long-chain monounsaturated fatty acid that has been shown to be a core component of nerve fibers and nerve cells.It can be used to treat and prevent many neurologic...Nervonic acid(NA,cis-15-tetracosenoic acid)is a very long-chain monounsaturated fatty acid that has been shown to be a core component of nerve fibers and nerve cells.It can be used to treat and prevent many neurological diseases.At present,commercially available NA is mainly derived from Acer truncatum seeds,which contain about 5%e6%NA in their seed oil.The aim of this study were to identify and analyze NA-containing Acer species that could be used as NA resource plants.For this purpose,46 Acer species seeds were collected in China and in some or all of the seed oils from these species 15 fatty acids were detected,including linoleic acid,oleic acid(C18:1D9,C18:1D11),erucic acid,palmitic acid,NA,linolenic acid(C18:3D6,9,12,C18:3D9,12,15),eicosenoic acid(C20:1D11,C20:1D13),stearic acid,behenic acid,tetracosanoic acid,arachidic acid,and docosadienoic acid.Nervonic acid was detected in all samples,but the content was highly variable among species.NA content over 9%was detected in eleven species,of which Acer elegantulum had the highest levels(13.90%).The seed oil content,seed weight,and fatty acid profiles varied among species,but the comprehensive evaluation value(W)showed that A.coriaceifolium could be a new potential NA resources plant.The results also showed that NA was significantly negatively correlated with palmitic acid,oleic acid,and eicosenoic acid,but positively correlated with eicosadienoic acid,behenic acid,erucic acid,and tetracosanoic acid,which indicate the probable pathway for NA biosynthesis in Acer plants.This study has identified Acer species that may serve as NA resources and will help guide subsequent species breeding programs.展开更多
Characterizing trait variation across different ecological scales in plant communities has been viewed as a way to gain insights into the mechanisms driving species coexistence.However,little is known about how change...Characterizing trait variation across different ecological scales in plant communities has been viewed as a way to gain insights into the mechanisms driving species coexistence.However,little is known about how changes in intraspecific and interspecific traits across sites influence species richness and community assembly,especially in understory herbaceous communities.Here we partitioned the variance of four functional traits(maximum height,leaf thickness,leaf area and specific leaf area)across four nested biological scales:individual,species,plot,and elevation to quantify the scale-dependent distributions of understory herbaceous trait variance.We also integrated the comparison of the trait variance ratios to null models to investigate the effects of different ecological processes on community assembly and functional diversity along a 1200-m elevational gradient in Yulong Mountain.We found interspecific trait variation was the main trait variation component for leaf traits,although intraspecific trait variation ranged from 10% to 28% of total variation.In particular,maximum height exhibited high plasticity,and intraspecific variation accounted for 44% of the total variation.Despite the fact that species composition varied across elevation and species richness decreased dramatically along the elevational gradient,there was little variance at our largest(elevation)scale in leaf traits and functional diversity remained constant along the elevational gradient,indicating that traits responded to smaller scale influences.External filtering was only observed at high elevations.However,strong internal filtering was detected along the entire elevational gradient in understory herbaceous communities,possibly due to competition.Our results provide evidence that species coexistence in understory herbaceous communities might be structured by differential niche-assembled processes.This approach ee integrating different biological scales of trait variation ee may provide a better understanding of the mechanisms involved in the structure of communities.展开更多
Seed dormancy and germination characteristics are important factors determining plant reproductive success, and may be expected to have a major influence on plant distribution. In this study, we aimed to explore the c...Seed dormancy and germination characteristics are important factors determining plant reproductive success, and may be expected to have a major influence on plant distribution. In this study, we aimed to explore the characteristics of seed dormancy and germination in two endemic Rheum species(Rheum nobile and Rheum alexandrae) in the Himalaya-Hengduan Mountains. To determine the type of dormancy,fresh seeds of the two species(one population each) were incubated in light at 25/15 and 15/5℃, and then dry after-ripening(DAR) seeds were incubated on water agar substrate with or without GA_3. To determine the effect of temperature and light on germination, DAR seeds of the two species(two populations each) were incubated both in the light and in the dark at several temperatures, including constant and alternating temperatures. Base temperature(T_b) and thermal times for 50% germination(θ_(50)) were calculated. DAR released physiological dormancy(PD), increasing final germination at 15/5℃ and widening the range of germination temperatures from higher to lower, indicative of type 2 non-deep PD for the two Rheum species. Light had no significant effect on germination of seeds from the two species(two populations each). Seeds of the two species germinated significantly better(>80%) at medium temperatures(10-25℃) than at extreme low(5℃) or high(35℃) temperatures. Alternating temperatures(25/15 and 15/5℃) did not significantly increase the final germination of the two species either in the light and in the dark, but it promoted seed germination more quickly than corresponding constant temperatures in the light in both Rh. alexandrae populations, especially at 15/5℃. Germination in response to temperature was well described by the thermal-time model at suboptimal temperatures. The estimated Tbvalues were 1 and 0.9℃, respectively, in two Rh. nobile populations; 4 and 4.1℃,respectively, in two Rh. alexandrae populations; θ_(50)(thermal time) were 100 and 125℃d, respectively in two Rh. nobile populations; 76.92 and 83.33℃d, respectively in two Rh. alexandrae populations. The dormancy type, and germination responses to temperature and light condition does not explain why the two Rheum species are distributed in contrasting habitats. However, these findings reflect an advantageous germination strategy of these two Rheum species to adapt to the same alpine environments.展开更多
Several conservation programs have been started for the critically endangered Sichou oak(Quercus sichourensis) since 2007.These programs include detailed field investigations,seedling cultivation and research on the f...Several conservation programs have been started for the critically endangered Sichou oak(Quercus sichourensis) since 2007.These programs include detailed field investigations,seedling cultivation and research on the fruit biology of the species.In this study,we first report on the five mature individual trees found in our 9-year field investigation.Thus far,a total of 10 mature individuals have been recorded.All Q.sichourensis trees are healthy and most produce healthy acorns.Acorns of Q.sichourensis are large with dry masses of 8.0-14.0 g.These acorns had high moisture contents at collection and died shortly after(7-28 d) when dried with silica gel.Characteristics of Q,sichourensis acorns varied between populations.Compared with the acorns from Funing,the acorns collected from Ceheng were bigger,more viable(germination percentage was up to 96%),less sensitive to desiccation,and germinated faster.Q.sichourensis occurs in regions with a distinct 5-6 month dry season.Habitat degradation is largely responsible for the rareness of Quercus sichorensis,but desiccation sensitivity of the acorns may also limit the regeneration of the species and potentially lead to its continued rareness.As a species with extremely small populations(PSESP),Q.sichourensis is facing high risk of extinction and should be defined as a Critically Endangered species in the global IUCN Red List.展开更多
Four new species of Orchidaceae from China,Heminium lijiangense,Peristylus fasciculatus,Platanthera milinensis,and Ponerorchis gongshanensis,together with a new country record,Peristylus tenuicallus,are described and ...Four new species of Orchidaceae from China,Heminium lijiangense,Peristylus fasciculatus,Platanthera milinensis,and Ponerorchis gongshanensis,together with a new country record,Peristylus tenuicallus,are described and illustrated based on morphological and/or phylogenetic analyses.Heminium lijiangense is closely related to H.elisabethae but differs from it by having the dorsal sepal ovate-orbicular and lip midlobe distinctly shorter than lateral lobes.P.fasciculatus is close to Peristylus tradescantifolius but is distinguished from it by having several fascicled and straight,root-like tubers(vs.one or two oblongoid tubers),old stems usually persistent,middle lobe of lip narrowly ligulate-lanceolate and half as long as the lateral lobes(vs.middle lobe deltoid,about a third as long as the lateral lobes or less),a raised callus at the base of each lateral lobe(vs.callus absent),spur gradually attenuate toward the apex(vs.spur clavate).Platanthera milinensis is similar to P.stenochila by sharing small green flowers and lip without a spur,but differs in having a creeping rhizome,a corymbose inflorescence,and a broadly ovate and slightly 3-lobed lip.Ponerochis gongshanensis is similar to P.faberi in its small flowers,but differs in having a linear leaf c.3 mm wide(vs.leaf 5-13 mm wide),in the lip having collar-like raised margins on the sides of the spur entrance,and a mid-lobe which is notched at the apex but not divided into two divergent lobules that are nearly as large as the lateral lobes,as in P.faberi.All the proposed species obtained high support in phylogenetic analysis as new species.The recently described genus Apetalanthe is reduced to synonymy of Ponerorchis and a new combination is made.展开更多
Two new species of Yushania(Poaceae,Bambusoideae,Arundinarieae)are described and illustrated from Hunan,China.Yushania longshanensis D.Z.Li&X.Y.Ye is distinguished from related species(Y.confusa,Y.angustifolia and...Two new species of Yushania(Poaceae,Bambusoideae,Arundinarieae)are described and illustrated from Hunan,China.Yushania longshanensis D.Z.Li&X.Y.Ye is distinguished from related species(Y.confusa,Y.angustifolia and Y.pachyclada)by having a thinner culm(0.2e0.3 cm in diameter),glabrous sheath scar,no oral setae,a large glabrous leaf blade(10e200.9e1.3 cm)and 3e4 pairs of secondary veins.Yushania stoloniforma D.Z.Li&X.Y.Ye has a distinctive scrambling habit,which differs from its putative close allies.Both of these two new species have a solitary branch at the basal nodes and can be assigned to Yushania sect.Yushania based on morphological features.Additionally,we treated Yushania gigantea T.P.Yi&L.Yang as a new synonym of Y.elevata T.P.Yi and renamed Y.microphylla T.P.Yi&L.Yang as Y.weiningensis D.Z.Li&X.Y.Ye.展开更多
Liparis aureolabella and L mengziensis,two new species from the karst region of southwestern China,and L bingzhongluoensis,a new species from montane region in Yunnan,are described and illustrated.L aureolabella is ea...Liparis aureolabella and L mengziensis,two new species from the karst region of southwestern China,and L bingzhongluoensis,a new species from montane region in Yunnan,are described and illustrated.L aureolabella is easily distinguished from its relatives by having abaxially purple leave with purple reticulate veins prominent adaxially,a lip auriculate at base,and falcate-lanceolate pollinia.Liparis mengziensis is closely related to L.petiolata and L.auriculata,but differs from them by having an ovate to broadly ovate leaf,purple lip and apex connate along the margins.Liparis bingzhongluoensis is similar to Liparis nanlingensis,but the new species is characterized by having a lip with two transparent ridges on its disc,longitudinally concave basal callus and triangular column wings.Phylogenetic analyses based on nuclear ribosomal ITS and plastid matK sequences showed that L aureolabella and L mengziensis are nested with L petiolata or L auriculata in a monophyletic clade.L bingzhongluoensis is sister to a clade formed by L.nanlingensis,L.tsii,L sasakii and L.krameri.Moreover,morphological comparisons strongly support that the three species as separated species newly to science.展开更多
Dryopteris sect.Diclisodon is a small section of ferns with about 12 species mainly distributed in East Asia.Here,we carried out morphological and phylogenetic analyses of this section.A new species from southwest Chi...Dryopteris sect.Diclisodon is a small section of ferns with about 12 species mainly distributed in East Asia.Here,we carried out morphological and phylogenetic analyses of this section.A new species from southwest China,D.gaoligongensis,is described and illustrated.Dryopteris gaoligongensis resembles D.indonesiana and D.sparsa,but differs by having a creeping rhizome and large 4-pinnate fronds.We also show that D.glabrior Ching&Z.Y.Liu is a distinct species;however,because it is a later homonym of D.glabrior Copel.,it should be renamed D.renchangiana.We conclude that a species previously known as D.nitidula,also an illegitimate homonym,should be recognized with a new name,D.sinonepalensis.We resolve the phylogenetic position of D.yoroii as sister to other sampled species of D.sect Diclisodon.Our phylogenetic analyses confirm the distinctiveness of D.gaoligongensis,D.renchangiana,and D.sinonepalensis.A key to species of D.sect Diclisodon in China is provided.展开更多
Three woody bamboo species collected in Hainan,China in 1940 have been described as Dinochloa based on vegetative specimens.However,the identity of these species has long been in doubt,largely because the vegetative p...Three woody bamboo species collected in Hainan,China in 1940 have been described as Dinochloa based on vegetative specimens.However,the identity of these species has long been in doubt,largely because the vegetative phase in species of Dinochloa is morphologically similar to that in species of Melocalamus,a climbing or scrambling bamboo genus of the paleotropical woody bamboos(Poaceae:Bambusoideae)that consists of about 15 species and one variety.To determine the phylogenetic affinity of the three Dinochloa species from Hainan,we sampled almost all recognized Chinese species of Melocalamus and representative species of Dinochloa as well as other closely related genera,performed molecular phylogenetic analysis,and compared their morphology based on herbarium and fieldwork investigation.Our ddRAD data indicate that the three species from Hainan are closely related to Melocalamus,not Dinochloa.Morphological analysis showed that these three species have a climbing habit but do not grow spirally,their culm leaves have smooth bases,and there is a ring of powder and/or tomenta above and below the nodes.Taken together our findings indicate that the three species from Hainan originally published in Dinochloa should be transferred to Melocalamus,i.e.,Melocalamus orenudus(McClure) D.Z.Li& J.X.Liu,Melocalamus puberulus(McClure) D.Z.Li & J.X.Liu,and Melocalamus utilis(McClure) D.Z.Li &J.X.Liu,respectively.This study concludes with an enumeration of Chinese species of Melocalamus,with a key to nine recognized species and one variety,and a lectotypification for M. compatiflorus.展开更多
Magnolia sinica is one of the most endangered Magnoliaceae species in China.Seed biology information concerning its long-term ex situ conservation and utilization is insufficient.This study investigated dormancy statu...Magnolia sinica is one of the most endangered Magnoliaceae species in China.Seed biology information concerning its long-term ex situ conservation and utilization is insufficient.This study investigated dormancy status,germination requirements and storage behavior of M.sinica.Freshly matured seeds germinated to ca.86.5%at 25/15℃but poorly at 30℃;GA3 and moist chilling promoted germination significantly at 20℃.Embryos grew at temperatures(alternating or constant)between 20℃and 25℃,but not at 5℃or 30℃.Our results indicate that M.sinica seeds possibly have non-deep simple mor-phophysiological dormancy(MPD).Seeds survived desiccation to 9.27%and 4.85%moisture content(MC)as well as a further 6-month storage at-20℃and in liquid nitrogen,including recovery in vitro as excised embryos.The established protocol ensured that at least 58%of seedlings were obtained after both cold storage and cryopreservation.These results indicate that both conventional seed banking and cryopreservation have potential as long-term ex situ conservation methods,although further optimized approaches are recommended for this critically endangered magnolia species.展开更多
Delimiting species requires multiple sources of evidence.Here,we delimited two varieties of Halenia elliptica(Gentianaceae)using several lines of evidence,including morphological traits and mating system in a sympatri...Delimiting species requires multiple sources of evidence.Here,we delimited two varieties of Halenia elliptica(Gentianaceae)using several lines of evidence,including morphological traits and mating system in a sympatric population,phylogenetic relationships based on nrITS and cpDNA(rpl16)data,and complete chloroplast genome sequences.Comparative analysis of 21 morphological traits clearly separates the two varieties of H.elliptica.Examination of the flowering process and pollination treatments indicate that H.elliptica var.grandiflora produces seeds via outcrossing,whereas H.elliptica var.elliptica produces seeds via mixed mating.Furthermore,hand-pollinated hybridization of the two varieties produced no seeds.Observations of pollinators showed that when bees began a pollination bout on H.elliptica var.grandiflora they preferred to continue pollinating this variety;however,when they began a pollination bout on H.elliptica var.elliptica,they showed no preference for either variety.Phylogenetic analysis confirmed the monophyly of H.elliptica,which was further divided into two monophyletic clades corresponding to the two varieties.A large number of variants from the chloroplast genomes reflected remarkable genetic dissimilarities between the two varieties of H.elliptica.We recommend that the two varieties of H.elliptica should be revised as two species(H.elliptica and H.grandiflora).Our findings indicate that H.elliptica varieties may have split into two separate species due to a shift in mating system,changes in flowering phenology and/or post-pollination reproductive isolation.展开更多
Walnuts are highly valued for their rich nutritional profile and wide medicinal applications.This demand has led to the intensification of breeding activities in major walnut production areas such as southwest China,i...Walnuts are highly valued for their rich nutritional profile and wide medicinal applications.This demand has led to the intensification of breeding activities in major walnut production areas such as southwest China,in order to develop more superior cultivars.With the increasing number of cultivars,accurate identification becomes fundamental to selecting the right cultivar for grafting,industrial processing or development of new cultivars.To ensure proper identification of cultivars and understand the genetic structure of wild and cultivated material,we genotyped 362 cultivated and wild individuals of walnut trees from southwest China(with two additional populations from Xinjiang,plus three cultivars from Canada,France and Belgium) using 36 polymorphic microsatellite loci.We found relatively low indices of genetic diversity(H_(O)=0.570,H_(E)=0.404,N_(A)=2.345) as well as a high level of clonality(>85% of cultivars),indicating reliance on genetically narrow sources of parental material for breeding.Our STRUCTURE and PCoA analyses generally delineated the two species,though considerable levels of introgression were also evident.More significantly,we detected a distinct genetic group of cultivated Juglans sigillata,which mainly comprised individuals of the popular ’Yangbidapao’ landrace.Finally,a core set of 18 SSR loci was selected,which was capable of identifying 32 cultivars.In a nutshell,our results call for more utilization of genetically disparate material,including wild walnut trees,as parental sources to breed for more cultivars.The data reported herein will significantly contribute towards the genetic improvement and conservation of the walnut germplasm in southwest China.展开更多
The composition of membrane lipids is sensitive to environmental stresses.Submergence is a type of stress often encountered by plants.However,how the molecular species of membrane lipids respond to submergence has not...The composition of membrane lipids is sensitive to environmental stresses.Submergence is a type of stress often encountered by plants.However,how the molecular species of membrane lipids respond to submergence has not yet been characterised.In this study,we used a lipidomic approach to profile the molecular species of membrane lipids in whole plants of Arabidopsis thaliana that were completely submerged for three days.The plants survived one day of submergence,after which,we found that the total membrane lipids were only subtly decreased,showing significant decreases of monogalactosyldiacylglycerol(MGDG)and phosphatidylcholine(PC)and an increase of phosphatidic acid(PA);however,the basic lipid composition was retained.In contrast,three days of submergence caused plants to die,and the membranes deteriorated via the rapid loss of 96% of lipid content together with a 229% increase in PA.The turnover of molecular species from PG and MGDG to PA indicated that submergenceinduced lipid changes occurred through PA-mediated degradation.In addition,molecular species of extraplastidic PG degraded sooner than plastidic ones,lyso-phospholipids exhibited various patterns of change,and the double-bond index(DBI)remained unchanged until membrane deterioration.Our results revealed the unique changes of membrane lipids upon submergence and suggested that the major cause of the massive lipid degradation could be anoxia.展开更多
Cymbidium(Orchidaceae:Epidendroideae),with around 60 species,is widely-distributed across Southeast Asia,providing a nice system for studying the processes that underlie patterns of biodiversity in the region.However,...Cymbidium(Orchidaceae:Epidendroideae),with around 60 species,is widely-distributed across Southeast Asia,providing a nice system for studying the processes that underlie patterns of biodiversity in the region.However,phylogenetic relationships of Cymbidium have not been well resolved,hampering investigations of species diversification and the biogeographical history of this genus.In this study,we construct a plastome phylogeny of 56 Cymbidium species,with four well-resolved major clades,which provides a framework for biogeographical and diversification rate analyses.Molecular dating and biogeographical analyses show that Cymbidium likely originated in the region spanning northern IndoBurma to the eastern Himalayas during the early Miocene(~21.10 Ma).It then rapidly diversified into four major clades in East Asia within approximately a million years during the middle Miocene.Cymbidium spp.migration to the adjacent regions(Borneo,Philippines,and Sulawesi)primarily occurred during the Pliocene-Pleistocene period.Our analyses indicate that the net diversification rate of Cymbidium has decreased since its origin,and is positively associated with changes in temperature and monsoon intensity.Favorable hydrothermal conditions brought by monsoon intensification in the early Miocene possibly contributed to the initial rapid diversification,after which the net diversification rate was reduced with the cooling climate after the middle Miocene.The transition from epiphytic to terrestrial habits may have enabled adaptation to cooler environments and colonization of northern niches,yet without a significant effect on diversification rates.This study provides new insights into how monsoon activity and temperature changes affected the diversification dynamics of plants in Southeast Asia.展开更多
Wintergreen oil is a folk medicine widely used in foods,pesticides,cosmetics and drugs.In China,nine out of 47 species within Gaultheria(Ericaceae)are traditionally used as Chinese medicinal wintergreens;however,phylo...Wintergreen oil is a folk medicine widely used in foods,pesticides,cosmetics and drugs.In China,nine out of 47 species within Gaultheria(Ericaceae)are traditionally used as Chinese medicinal wintergreens;however,phylogenetic approaches currently used to discriminating these species remain unsatisfactory.In this study,we sequenced and characterized plastomes from nine Chinese wintergreen species and identified candidate DNA barcoding regions for Gaultheria.Each Gaultheria plastome contained 110 unique genes(76 protein-coding,30 tRNA,and four rRNA genes).Duplication of trnfM,rps14,and rpl23 genes were detected,while all plastomes lacked ycf1 and ycf2 genes.Gaultheria plastomes shared substantially contracted SSC regions that contained only the ndhF gene.Moreover,plastomes of Gaultheria leucocarpa var.yunnanensis contained an inversion in the LSC region and an IR expansion to cover the ndhF gene.Multiple rearrangement events apparently occurred between the Gaultheria plastomes and those from several previously reported families in Ericales.Our phylogenetic reconstruction using 42 plastomes revealed well-supported relationships within all nine Gaultheria species.Additionally,seven mutational hotspot regions were identified as potential DNA barcodes for Chinese medicinal wintergreens.Our study is the first to generate complete plastomes and describe the structural variations of the complicated genus Gaultheria.In addition,our findings provide important resources for identification of Chinese medicinal wintergreens.展开更多
Although great accomplishments of in situ conservation have been made during the last decade throughout the world, there is an urgent need to conduct more targeted research to explore many basic questions about crop w...Although great accomplishments of in situ conservation have been made during the last decade throughout the world, there is an urgent need to conduct more targeted research to explore many basic questions about crop wild relatives (CWR) in situ conservation such as how to better identify and manage the target in situ conservation populations of CWR. In this study, we performed an extensive field investigation of 201 natural populations or habitats of O. rufipogon, a seriously endangered wild progenitor of cultivated rice in China. Our updated information suggests that: 1) the majority of the natural populations have been extinct throughout China, which leads to serious fragmentation of the population system as a whole;and 2) the survived populations have become small in size and thus fragmented within the population as a result of the loss of subpopulations. To assess the relationships between the biodiversity education and conservation of wild rice, we employed participatory approaches in the field investigation. Our data indicate that the continuous rapid decline of biodiversity education seemed closely related to the extinction of wild rice germplasm. These findings imply the potential necessity and huge challenge for making in situ conservation plans in the future. By means of our understanding of ecogeography, sociology and culture, and population genetics of the species, we propose a strategy for selecting in situ conservation locations as well as priority sites for establishing in situ conservation practices in China.展开更多
Pseudosasa gracilis(Poaceae:Bambusoideae)is a temperate woody bamboo species endemic to Southcentral China with a narrow distribution.Previous phylogenetic studies revealed an unexpected,isolated phylogenetic position...Pseudosasa gracilis(Poaceae:Bambusoideae)is a temperate woody bamboo species endemic to Southcentral China with a narrow distribution.Previous phylogenetic studies revealed an unexpected,isolated phylogenetic position of Ps.gracilis.Here we conducted phylogenomic analysis by sampling populations of Ps.gracilis and its sympatric species Ps.nanunica and Sinosasa polytricha reflecting different genomic signals,by deep genome skimming.Integrating molecular evidence from chloroplast genes and genome-wide SNPs,we deciphered the phylogenetic relationships of Ps.gracilis.Both plastid and nuclear data indicate that Ps.gracilis is more closely related to Sinosasa,which is discordant with the taxonomic treatment.To further explore this molecular-morphological conflict,we screened 411“perfect-copy”syntenic genes to reconstruct phylogenies using both the concatenation and coalescent methods.We observed extensive discordance between gene trees and the putative species tree.A significant hybridization event was detected based on 411 genes from the D subgenome,showing Ps.gracilis was a hybrid descendant between Sinosasa longiligulata and Ps.nanunica,with 63.56%and 36.44%inheritance probabilities of each parent.Moreover,introgression events were detected in the C subgenome between Ps.gracilis and S.polytricha in the same distribution region.Our findings suggest that sympatric hybridization and introgression play a crucial role in the origin of Ps.gracilis.By providing an empirical example of bamboo of hybrid origin using comprehensive analyses based on genomic data from different inheritance systems and morphological characters,our study represents a step forward in understanding of reticulate evolution of bamboos.展开更多
The number of trichomes significantly increased in CRISPR/Cas9-edited BrrTCP4b turnip(Brassica rapa var.rapa)plants.However,the underlying molecular mechanism remains to be uncovered.In this study,we performed the Y2H...The number of trichomes significantly increased in CRISPR/Cas9-edited BrrTCP4b turnip(Brassica rapa var.rapa)plants.However,the underlying molecular mechanism remains to be uncovered.In this study,we performed the Y2H screen using BrrTCP4b as the bait,which unveiled an interaction between BrrTCP4b and BrrTTG1,a pivotal WD40-repeat protein transcription factor in the MYB-bHLH-WD40(MBW)complex.This physical interaction was further validated through bimolecular luciferase complementation and co-immunoprecipitation.Furthermore,it was found that the interaction between BrrTCP4b and BrrTTG1 could inhibit the activity of MBW complex,resulting in decreased expression of BrrGL2,a positive regulator of trichomes development.In contrast,AtTCP4 is known to regulate trichomes development by interacting with AtGL3 in Arabidopsis thaliana.Overall,this study revealed that BrrTCP4b is involved in trichome development by interacting with BrrTTG1 in turnip,indicating a divergence from the mechanisms observed in model plant A.thaliana.The findings contribute to our understanding of the regulatory mechanisms governing trichome development in the non-model plants turnip.展开更多
Descriptions of floral traits based on the visual capabilities of pollinators would advance our understanding of flower evolution and plantepollinator relationships.One such trait is the contrasting UV bullseye color ...Descriptions of floral traits based on the visual capabilities of pollinators would advance our understanding of flower evolution and plantepollinator relationships.One such trait is the contrasting UV bullseye color pattern,which is invisible to human eyes but can be perceived by bee pollinators.However,it remains largely unknown how UV bullseye size affects male and female reproductive fitness.We examined UV bullseye patterns in the dioecious Herpetospermum pedunculosum,and quantified the effects of UV bullseye size on male and female fitness.Both UV bullseye size and flower size were larger in male flowers than in female flowers.The dominant pollinators of H.pedunculosum were bees,which could perceive the UV bullseye pattern.Bee pollinators exhibited a preference for male flowers with nectar rewards,and visited a greater number of male flowers on plants with a larger UV bullseye.Male reproductive fitness was found to decrease in plants with larger UV bullseyes,likely due to the high rate of intra-plant pollen transfer.Rewardless female flowers were less attractive to bee pollinators,resulting in pollen limitation of seed production.Female flowers with moderate UV bullseye size produced more seeds.Our results suggest that UV bullseye is subject to different selection via male and female fitness of H.pedunculosum with deceptive pollination,and large UV bullseye is generally not favored.This research is the first to examine the relationship between UV bullseye size and plant reproductive success,highlighting that floral evolution should be investigated from the pollinator's eye in future research.展开更多
基金funded by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB31010000)the National Key Basic Research Program of China (2014CB954100)the Program of Science and Technology Talents Training of Yunnan Province (2017HA014)
文摘Global warming increases the vulnerability of plants, especially alpine herbaceous species, to local extinction. In this study, we collected species distribution information from herbarium specimens for ten selected Cyananthus and Primula alpine species endemic to the Himalaya-Hengduan Mountains(HHM).Combined with climate data from WorldClim, we used Maximum Entropy Modeling(MaxEnt) to project distributional changes from the current time period to 2070. Our predictions indicate that, under a wide range of climate change scenarios, the distributions of all species will shift upward in elevation and northward in latitude; furthermore, under these scenarios, species will expand the size of their range. For the majority of the species in this study, habitats are available to mitigate upward and northward shifts that are projected to be induced by changing climate. If current climate projections, however, increase in magnitude or continue to increase past our projection dates, suitable habitat for future occupation by alpine species will be limited as we predict range contraction or less range expansion for some of the species under more intensified climate scenarios. Our study not only underscores the value of herbarium source information for future climate model projections but also suggests that future studies on the effects of climate change on alpine species should include additional biotic and abiotic factors to provide greater resolution of the local dynamics associated with species persistence under a warming climate.
基金supported by the National Natural Science Foundation of China(grant number 31671732).
文摘Nervonic acid(NA,cis-15-tetracosenoic acid)is a very long-chain monounsaturated fatty acid that has been shown to be a core component of nerve fibers and nerve cells.It can be used to treat and prevent many neurological diseases.At present,commercially available NA is mainly derived from Acer truncatum seeds,which contain about 5%e6%NA in their seed oil.The aim of this study were to identify and analyze NA-containing Acer species that could be used as NA resource plants.For this purpose,46 Acer species seeds were collected in China and in some or all of the seed oils from these species 15 fatty acids were detected,including linoleic acid,oleic acid(C18:1D9,C18:1D11),erucic acid,palmitic acid,NA,linolenic acid(C18:3D6,9,12,C18:3D9,12,15),eicosenoic acid(C20:1D11,C20:1D13),stearic acid,behenic acid,tetracosanoic acid,arachidic acid,and docosadienoic acid.Nervonic acid was detected in all samples,but the content was highly variable among species.NA content over 9%was detected in eleven species,of which Acer elegantulum had the highest levels(13.90%).The seed oil content,seed weight,and fatty acid profiles varied among species,but the comprehensive evaluation value(W)showed that A.coriaceifolium could be a new potential NA resources plant.The results also showed that NA was significantly negatively correlated with palmitic acid,oleic acid,and eicosenoic acid,but positively correlated with eicosadienoic acid,behenic acid,erucic acid,and tetracosanoic acid,which indicate the probable pathway for NA biosynthesis in Acer plants.This study has identified Acer species that may serve as NA resources and will help guide subsequent species breeding programs.
基金supported by the National Key Basic Research Program of China (2014CB954100)the Ministry of Science and Technology of the People's Republic of China (2012FY110800)the Applied Fundamental Research Foundation of Yunnan Province (2014GA003)
文摘Characterizing trait variation across different ecological scales in plant communities has been viewed as a way to gain insights into the mechanisms driving species coexistence.However,little is known about how changes in intraspecific and interspecific traits across sites influence species richness and community assembly,especially in understory herbaceous communities.Here we partitioned the variance of four functional traits(maximum height,leaf thickness,leaf area and specific leaf area)across four nested biological scales:individual,species,plot,and elevation to quantify the scale-dependent distributions of understory herbaceous trait variance.We also integrated the comparison of the trait variance ratios to null models to investigate the effects of different ecological processes on community assembly and functional diversity along a 1200-m elevational gradient in Yulong Mountain.We found interspecific trait variation was the main trait variation component for leaf traits,although intraspecific trait variation ranged from 10% to 28% of total variation.In particular,maximum height exhibited high plasticity,and intraspecific variation accounted for 44% of the total variation.Despite the fact that species composition varied across elevation and species richness decreased dramatically along the elevational gradient,there was little variance at our largest(elevation)scale in leaf traits and functional diversity remained constant along the elevational gradient,indicating that traits responded to smaller scale influences.External filtering was only observed at high elevations.However,strong internal filtering was detected along the entire elevational gradient in understory herbaceous communities,possibly due to competition.Our results provide evidence that species coexistence in understory herbaceous communities might be structured by differential niche-assembled processes.This approach ee integrating different biological scales of trait variation ee may provide a better understanding of the mechanisms involved in the structure of communities.
基金supported by National Key Research and Development Program of China (2017YFC0505201)NSFC (grant 31670206 to Z.-M. L. and 31570228 to B. S.),major Program of NSFC (grant 31590823 to H. S.)+1 种基金the Orientation Training Programme for Postdoctoral Fellows from Yunnan Province to D.-L. P.the Young Academic and Technical Leader Raising Foundation of Yunnan Province to B. S.
文摘Seed dormancy and germination characteristics are important factors determining plant reproductive success, and may be expected to have a major influence on plant distribution. In this study, we aimed to explore the characteristics of seed dormancy and germination in two endemic Rheum species(Rheum nobile and Rheum alexandrae) in the Himalaya-Hengduan Mountains. To determine the type of dormancy,fresh seeds of the two species(one population each) were incubated in light at 25/15 and 15/5℃, and then dry after-ripening(DAR) seeds were incubated on water agar substrate with or without GA_3. To determine the effect of temperature and light on germination, DAR seeds of the two species(two populations each) were incubated both in the light and in the dark at several temperatures, including constant and alternating temperatures. Base temperature(T_b) and thermal times for 50% germination(θ_(50)) were calculated. DAR released physiological dormancy(PD), increasing final germination at 15/5℃ and widening the range of germination temperatures from higher to lower, indicative of type 2 non-deep PD for the two Rheum species. Light had no significant effect on germination of seeds from the two species(two populations each). Seeds of the two species germinated significantly better(>80%) at medium temperatures(10-25℃) than at extreme low(5℃) or high(35℃) temperatures. Alternating temperatures(25/15 and 15/5℃) did not significantly increase the final germination of the two species either in the light and in the dark, but it promoted seed germination more quickly than corresponding constant temperatures in the light in both Rh. alexandrae populations, especially at 15/5℃. Germination in response to temperature was well described by the thermal-time model at suboptimal temperatures. The estimated Tbvalues were 1 and 0.9℃, respectively, in two Rh. nobile populations; 4 and 4.1℃,respectively, in two Rh. alexandrae populations; θ_(50)(thermal time) were 100 and 125℃d, respectively in two Rh. nobile populations; 76.92 and 83.33℃d, respectively in two Rh. alexandrae populations. The dormancy type, and germination responses to temperature and light condition does not explain why the two Rheum species are distributed in contrasting habitats. However, these findings reflect an advantageous germination strategy of these two Rheum species to adapt to the same alpine environments.
基金supported by NSFCYunnan joint fund to support key projects (No. U1302262 and U1502231)
文摘Several conservation programs have been started for the critically endangered Sichou oak(Quercus sichourensis) since 2007.These programs include detailed field investigations,seedling cultivation and research on the fruit biology of the species.In this study,we first report on the five mature individual trees found in our 9-year field investigation.Thus far,a total of 10 mature individuals have been recorded.All Q.sichourensis trees are healthy and most produce healthy acorns.Acorns of Q.sichourensis are large with dry masses of 8.0-14.0 g.These acorns had high moisture contents at collection and died shortly after(7-28 d) when dried with silica gel.Characteristics of Q,sichourensis acorns varied between populations.Compared with the acorns from Funing,the acorns collected from Ceheng were bigger,more viable(germination percentage was up to 96%),less sensitive to desiccation,and germinated faster.Q.sichourensis occurs in regions with a distinct 5-6 month dry season.Habitat degradation is largely responsible for the rareness of Quercus sichorensis,but desiccation sensitivity of the acorns may also limit the regeneration of the species and potentially lead to its continued rareness.As a species with extremely small populations(PSESP),Q.sichourensis is facing high risk of extinction and should be defined as a Critically Endangered species in the global IUCN Red List.
基金Project of Orchid Biodiversity Survey of ChinaNational Forestry and Grassland Administration+2 种基金the National Natural Science Foundation of China(No.31670194)the Large-scale Scientific Facilities of theChinese Academy of Sciences(Grant No.2017-LSFGBOWS-02)the National Wild Plant Germplasm Resource Center。
文摘Four new species of Orchidaceae from China,Heminium lijiangense,Peristylus fasciculatus,Platanthera milinensis,and Ponerorchis gongshanensis,together with a new country record,Peristylus tenuicallus,are described and illustrated based on morphological and/or phylogenetic analyses.Heminium lijiangense is closely related to H.elisabethae but differs from it by having the dorsal sepal ovate-orbicular and lip midlobe distinctly shorter than lateral lobes.P.fasciculatus is close to Peristylus tradescantifolius but is distinguished from it by having several fascicled and straight,root-like tubers(vs.one or two oblongoid tubers),old stems usually persistent,middle lobe of lip narrowly ligulate-lanceolate and half as long as the lateral lobes(vs.middle lobe deltoid,about a third as long as the lateral lobes or less),a raised callus at the base of each lateral lobe(vs.callus absent),spur gradually attenuate toward the apex(vs.spur clavate).Platanthera milinensis is similar to P.stenochila by sharing small green flowers and lip without a spur,but differs in having a creeping rhizome,a corymbose inflorescence,and a broadly ovate and slightly 3-lobed lip.Ponerochis gongshanensis is similar to P.faberi in its small flowers,but differs in having a linear leaf c.3 mm wide(vs.leaf 5-13 mm wide),in the lip having collar-like raised margins on the sides of the spur entrance,and a mid-lobe which is notched at the apex but not divided into two divergent lobules that are nearly as large as the lateral lobes,as in P.faberi.All the proposed species obtained high support in phylogenetic analysis as new species.The recently described genus Apetalanthe is reduced to synonymy of Ponerorchis and a new combination is made.
基金funded by the National Natural Science Foundation of China(nos.31800315,31430011)the Applied and Fundamental Research Foundation of Yunnan Province(2019FD059).
文摘Two new species of Yushania(Poaceae,Bambusoideae,Arundinarieae)are described and illustrated from Hunan,China.Yushania longshanensis D.Z.Li&X.Y.Ye is distinguished from related species(Y.confusa,Y.angustifolia and Y.pachyclada)by having a thinner culm(0.2e0.3 cm in diameter),glabrous sheath scar,no oral setae,a large glabrous leaf blade(10e200.9e1.3 cm)and 3e4 pairs of secondary veins.Yushania stoloniforma D.Z.Li&X.Y.Ye has a distinctive scrambling habit,which differs from its putative close allies.Both of these two new species have a solitary branch at the basal nodes and can be assigned to Yushania sect.Yushania based on morphological features.Additionally,we treated Yushania gigantea T.P.Yi&L.Yang as a new synonym of Y.elevata T.P.Yi and renamed Y.microphylla T.P.Yi&L.Yang as Y.weiningensis D.Z.Li&X.Y.Ye.
基金financially supported by National Forestry and Grassland Administration(2019073019,2019073003,2019073002)National Science&Technology Infrastructure,the Large-scale Scientific Facilities of the Chinese Academy of Sciences(2017LSFGBOWS-02)+4 种基金Science and Technology Basic Resources Investigation Program of China"Survey and Germplasm Conservation of Plant Species with Extremely Small Populations in South-west China"(2017FY100100)grants from Southeast Asia Biodiversity Research Institute,Chinese Academy of Sciences(Grant No.Y4ZK111B01)the National Natural Science Foundation of China(Grant Nos.31670194,31870195)the Special Investigation on Vulnerable Habitat Plants in Daweishan Area,Yunnan,China(2018-2021)the CAS 135 Program(2017XTBG-T03)。
文摘Liparis aureolabella and L mengziensis,two new species from the karst region of southwestern China,and L bingzhongluoensis,a new species from montane region in Yunnan,are described and illustrated.L aureolabella is easily distinguished from its relatives by having abaxially purple leave with purple reticulate veins prominent adaxially,a lip auriculate at base,and falcate-lanceolate pollinia.Liparis mengziensis is closely related to L.petiolata and L.auriculata,but differs from them by having an ovate to broadly ovate leaf,purple lip and apex connate along the margins.Liparis bingzhongluoensis is similar to Liparis nanlingensis,but the new species is characterized by having a lip with two transparent ridges on its disc,longitudinally concave basal callus and triangular column wings.Phylogenetic analyses based on nuclear ribosomal ITS and plastid matK sequences showed that L aureolabella and L mengziensis are nested with L petiolata or L auriculata in a monophyletic clade.L bingzhongluoensis is sister to a clade formed by L.nanlingensis,L.tsii,L sasakii and L.krameri.Moreover,morphological comparisons strongly support that the three species as separated species newly to science.
基金the Strategic Priority Research Program of Chinese Academy of Sciences(XDB31000000)the National Natural Science Foundation of China(31970232)the Technological leading talent project of Yunnan(2017HA014)。
文摘Dryopteris sect.Diclisodon is a small section of ferns with about 12 species mainly distributed in East Asia.Here,we carried out morphological and phylogenetic analyses of this section.A new species from southwest China,D.gaoligongensis,is described and illustrated.Dryopteris gaoligongensis resembles D.indonesiana and D.sparsa,but differs by having a creeping rhizome and large 4-pinnate fronds.We also show that D.glabrior Ching&Z.Y.Liu is a distinct species;however,because it is a later homonym of D.glabrior Copel.,it should be renamed D.renchangiana.We conclude that a species previously known as D.nitidula,also an illegitimate homonym,should be recognized with a new name,D.sinonepalensis.We resolve the phylogenetic position of D.yoroii as sister to other sampled species of D.sect Diclisodon.Our phylogenetic analyses confirm the distinctiveness of D.gaoligongensis,D.renchangiana,and D.sinonepalensis.A key to species of D.sect Diclisodon in China is provided.
基金supported by the National Natural Science Foundation of China (31670396 and 31800181)Postdoctoral Directional Training Foundation of Yunnan Province,China (E2317482)the Key R & D program of Yunnan Province,China (202103AC100003)。
文摘Three woody bamboo species collected in Hainan,China in 1940 have been described as Dinochloa based on vegetative specimens.However,the identity of these species has long been in doubt,largely because the vegetative phase in species of Dinochloa is morphologically similar to that in species of Melocalamus,a climbing or scrambling bamboo genus of the paleotropical woody bamboos(Poaceae:Bambusoideae)that consists of about 15 species and one variety.To determine the phylogenetic affinity of the three Dinochloa species from Hainan,we sampled almost all recognized Chinese species of Melocalamus and representative species of Dinochloa as well as other closely related genera,performed molecular phylogenetic analysis,and compared their morphology based on herbarium and fieldwork investigation.Our ddRAD data indicate that the three species from Hainan are closely related to Melocalamus,not Dinochloa.Morphological analysis showed that these three species have a climbing habit but do not grow spirally,their culm leaves have smooth bases,and there is a ring of powder and/or tomenta above and below the nodes.Taken together our findings indicate that the three species from Hainan originally published in Dinochloa should be transferred to Melocalamus,i.e.,Melocalamus orenudus(McClure) D.Z.Li& J.X.Liu,Melocalamus puberulus(McClure) D.Z.Li & J.X.Liu,and Melocalamus utilis(McClure) D.Z.Li &J.X.Liu,respectively.This study concludes with an enumeration of Chinese species of Melocalamus,with a key to nine recognized species and one variety,and a lectotypification for M. compatiflorus.
文摘Magnolia sinica is one of the most endangered Magnoliaceae species in China.Seed biology information concerning its long-term ex situ conservation and utilization is insufficient.This study investigated dormancy status,germination requirements and storage behavior of M.sinica.Freshly matured seeds germinated to ca.86.5%at 25/15℃but poorly at 30℃;GA3 and moist chilling promoted germination significantly at 20℃.Embryos grew at temperatures(alternating or constant)between 20℃and 25℃,but not at 5℃or 30℃.Our results indicate that M.sinica seeds possibly have non-deep simple mor-phophysiological dormancy(MPD).Seeds survived desiccation to 9.27%and 4.85%moisture content(MC)as well as a further 6-month storage at-20℃and in liquid nitrogen,including recovery in vitro as excised embryos.The established protocol ensured that at least 58%of seedlings were obtained after both cold storage and cryopreservation.These results indicate that both conventional seed banking and cryopreservation have potential as long-term ex situ conservation methods,although further optimized approaches are recommended for this critically endangered magnolia species.
基金the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0502)National Key R&D Program of China(2017YFC0505200)+1 种基金National Natural Science Foundation of China(31460096 and 31590823)State Key Laboratory of Phytochemistry and Plant Resources in West China(P2020-KF04).
文摘Delimiting species requires multiple sources of evidence.Here,we delimited two varieties of Halenia elliptica(Gentianaceae)using several lines of evidence,including morphological traits and mating system in a sympatric population,phylogenetic relationships based on nrITS and cpDNA(rpl16)data,and complete chloroplast genome sequences.Comparative analysis of 21 morphological traits clearly separates the two varieties of H.elliptica.Examination of the flowering process and pollination treatments indicate that H.elliptica var.grandiflora produces seeds via outcrossing,whereas H.elliptica var.elliptica produces seeds via mixed mating.Furthermore,hand-pollinated hybridization of the two varieties produced no seeds.Observations of pollinators showed that when bees began a pollination bout on H.elliptica var.grandiflora they preferred to continue pollinating this variety;however,when they began a pollination bout on H.elliptica var.elliptica,they showed no preference for either variety.Phylogenetic analysis confirmed the monophyly of H.elliptica,which was further divided into two monophyletic clades corresponding to the two varieties.A large number of variants from the chloroplast genomes reflected remarkable genetic dissimilarities between the two varieties of H.elliptica.We recommend that the two varieties of H.elliptica should be revised as two species(H.elliptica and H.grandiflora).Our findings indicate that H.elliptica varieties may have split into two separate species due to a shift in mating system,changes in flowering phenology and/or post-pollination reproductive isolation.
基金the National Natural Science Foundation of China (31770367,41971071)Top-notch Young Talents Project of Yunnan Provincial "Ten Thousand Talents Program"(YNWR-QNBJ-2018-146)+5 种基金the Key Research Program of Frontier Sciences,CAS (ZDBS-LY-7001)Natural Science Foundation of Yunnan (2017FB027)CAS’ Youth Innovation Promotion Association (2019385)the Biological Resources Program,Chinese Academy of Sciences (KFJ-BRP-017-XX)the Postdoctoral International Exchange Program of the Office of China Postdoctoral Councilthe Postdoctoral Targeted Funding and Postdoctoral Research Fund of Yunnan Province
文摘Walnuts are highly valued for their rich nutritional profile and wide medicinal applications.This demand has led to the intensification of breeding activities in major walnut production areas such as southwest China,in order to develop more superior cultivars.With the increasing number of cultivars,accurate identification becomes fundamental to selecting the right cultivar for grafting,industrial processing or development of new cultivars.To ensure proper identification of cultivars and understand the genetic structure of wild and cultivated material,we genotyped 362 cultivated and wild individuals of walnut trees from southwest China(with two additional populations from Xinjiang,plus three cultivars from Canada,France and Belgium) using 36 polymorphic microsatellite loci.We found relatively low indices of genetic diversity(H_(O)=0.570,H_(E)=0.404,N_(A)=2.345) as well as a high level of clonality(>85% of cultivars),indicating reliance on genetically narrow sources of parental material for breeding.Our STRUCTURE and PCoA analyses generally delineated the two species,though considerable levels of introgression were also evident.More significantly,we detected a distinct genetic group of cultivated Juglans sigillata,which mainly comprised individuals of the popular ’Yangbidapao’ landrace.Finally,a core set of 18 SSR loci was selected,which was capable of identifying 32 cultivars.In a nutshell,our results call for more utilization of genetically disparate material,including wild walnut trees,as parental sources to breed for more cultivars.The data reported herein will significantly contribute towards the genetic improvement and conservation of the walnut germplasm in southwest China.
基金Acknowledgements The authors thank Mary Roth (Kansas Lipidomics Research Center) for her assistance with the lipid analysis, Dr. Yanxia Jia for the use of the IMAGING-PAM chlorophyll fluorometer.
文摘The composition of membrane lipids is sensitive to environmental stresses.Submergence is a type of stress often encountered by plants.However,how the molecular species of membrane lipids respond to submergence has not yet been characterised.In this study,we used a lipidomic approach to profile the molecular species of membrane lipids in whole plants of Arabidopsis thaliana that were completely submerged for three days.The plants survived one day of submergence,after which,we found that the total membrane lipids were only subtly decreased,showing significant decreases of monogalactosyldiacylglycerol(MGDG)and phosphatidylcholine(PC)and an increase of phosphatidic acid(PA);however,the basic lipid composition was retained.In contrast,three days of submergence caused plants to die,and the membranes deteriorated via the rapid loss of 96% of lipid content together with a 229% increase in PA.The turnover of molecular species from PG and MGDG to PA indicated that submergenceinduced lipid changes occurred through PA-mediated degradation.In addition,molecular species of extraplastidic PG degraded sooner than plastidic ones,lyso-phospholipids exhibited various patterns of change,and the double-bond index(DBI)remained unchanged until membrane deterioration.Our results revealed the unique changes of membrane lipids upon submergence and suggested that the major cause of the massive lipid degradation could be anoxia.
基金supported by grants from the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB31000000)The 14th Five-Year Plan of the Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences (XTBG-1450101)+3 种基金the Science and Technology Basic Resources Investigation Program of China (2021FY100200)the Key Basic Research Program of Yunnan Province,China (202101BC070003)the Yunnan Revitalization Talent Support Program"Young Talent"and"Innovation Team"ProjectsEcological and Environmental Conservation Program from the Department of Ecology and Environment of Yunnan Province。
文摘Cymbidium(Orchidaceae:Epidendroideae),with around 60 species,is widely-distributed across Southeast Asia,providing a nice system for studying the processes that underlie patterns of biodiversity in the region.However,phylogenetic relationships of Cymbidium have not been well resolved,hampering investigations of species diversification and the biogeographical history of this genus.In this study,we construct a plastome phylogeny of 56 Cymbidium species,with four well-resolved major clades,which provides a framework for biogeographical and diversification rate analyses.Molecular dating and biogeographical analyses show that Cymbidium likely originated in the region spanning northern IndoBurma to the eastern Himalayas during the early Miocene(~21.10 Ma).It then rapidly diversified into four major clades in East Asia within approximately a million years during the middle Miocene.Cymbidium spp.migration to the adjacent regions(Borneo,Philippines,and Sulawesi)primarily occurred during the Pliocene-Pleistocene period.Our analyses indicate that the net diversification rate of Cymbidium has decreased since its origin,and is positively associated with changes in temperature and monsoon intensity.Favorable hydrothermal conditions brought by monsoon intensification in the early Miocene possibly contributed to the initial rapid diversification,after which the net diversification rate was reduced with the cooling climate after the middle Miocene.The transition from epiphytic to terrestrial habits may have enabled adaptation to cooler environments and colonization of northern niches,yet without a significant effect on diversification rates.This study provides new insights into how monsoon activity and temperature changes affected the diversification dynamics of plants in Southeast Asia.
基金the National Natural Science Foundation of China(31960080,41671052 and 42175139)the Reserve Talents of Young and Middle-aged Academic and Technical Leaders in Yunnan province(202005AC160020)the Program Innovative Research Team in Science and Technology in Yunnan Province(202005AE160004).
文摘Wintergreen oil is a folk medicine widely used in foods,pesticides,cosmetics and drugs.In China,nine out of 47 species within Gaultheria(Ericaceae)are traditionally used as Chinese medicinal wintergreens;however,phylogenetic approaches currently used to discriminating these species remain unsatisfactory.In this study,we sequenced and characterized plastomes from nine Chinese wintergreen species and identified candidate DNA barcoding regions for Gaultheria.Each Gaultheria plastome contained 110 unique genes(76 protein-coding,30 tRNA,and four rRNA genes).Duplication of trnfM,rps14,and rpl23 genes were detected,while all plastomes lacked ycf1 and ycf2 genes.Gaultheria plastomes shared substantially contracted SSC regions that contained only the ndhF gene.Moreover,plastomes of Gaultheria leucocarpa var.yunnanensis contained an inversion in the LSC region and an IR expansion to cover the ndhF gene.Multiple rearrangement events apparently occurred between the Gaultheria plastomes and those from several previously reported families in Ericales.Our phylogenetic reconstruction using 42 plastomes revealed well-supported relationships within all nine Gaultheria species.Additionally,seven mutational hotspot regions were identified as potential DNA barcodes for Chinese medicinal wintergreens.Our study is the first to generate complete plastomes and describe the structural variations of the complicated genus Gaultheria.In addition,our findings provide important resources for identification of Chinese medicinal wintergreens.
文摘Although great accomplishments of in situ conservation have been made during the last decade throughout the world, there is an urgent need to conduct more targeted research to explore many basic questions about crop wild relatives (CWR) in situ conservation such as how to better identify and manage the target in situ conservation populations of CWR. In this study, we performed an extensive field investigation of 201 natural populations or habitats of O. rufipogon, a seriously endangered wild progenitor of cultivated rice in China. Our updated information suggests that: 1) the majority of the natural populations have been extinct throughout China, which leads to serious fragmentation of the population system as a whole;and 2) the survived populations have become small in size and thus fragmented within the population as a result of the loss of subpopulations. To assess the relationships between the biodiversity education and conservation of wild rice, we employed participatory approaches in the field investigation. Our data indicate that the continuous rapid decline of biodiversity education seemed closely related to the extinction of wild rice germplasm. These findings imply the potential necessity and huge challenge for making in situ conservation plans in the future. By means of our understanding of ecogeography, sociology and culture, and population genetics of the species, we propose a strategy for selecting in situ conservation locations as well as priority sites for establishing in situ conservation practices in China.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB31000000)the National Natural Science Foundation of China(32200193).
文摘Pseudosasa gracilis(Poaceae:Bambusoideae)is a temperate woody bamboo species endemic to Southcentral China with a narrow distribution.Previous phylogenetic studies revealed an unexpected,isolated phylogenetic position of Ps.gracilis.Here we conducted phylogenomic analysis by sampling populations of Ps.gracilis and its sympatric species Ps.nanunica and Sinosasa polytricha reflecting different genomic signals,by deep genome skimming.Integrating molecular evidence from chloroplast genes and genome-wide SNPs,we deciphered the phylogenetic relationships of Ps.gracilis.Both plastid and nuclear data indicate that Ps.gracilis is more closely related to Sinosasa,which is discordant with the taxonomic treatment.To further explore this molecular-morphological conflict,we screened 411“perfect-copy”syntenic genes to reconstruct phylogenies using both the concatenation and coalescent methods.We observed extensive discordance between gene trees and the putative species tree.A significant hybridization event was detected based on 411 genes from the D subgenome,showing Ps.gracilis was a hybrid descendant between Sinosasa longiligulata and Ps.nanunica,with 63.56%and 36.44%inheritance probabilities of each parent.Moreover,introgression events were detected in the C subgenome between Ps.gracilis and S.polytricha in the same distribution region.Our findings suggest that sympatric hybridization and introgression play a crucial role in the origin of Ps.gracilis.By providing an empirical example of bamboo of hybrid origin using comprehensive analyses based on genomic data from different inheritance systems and morphological characters,our study represents a step forward in understanding of reticulate evolution of bamboos.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences,Pan-Third Pole Environment Study for a Green Silk Road(Pan-TPE)(XDA2004010306)the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0502)Science and Technology Program of Xizang Autonomous Region(XZ202001ZY0003G).
文摘The number of trichomes significantly increased in CRISPR/Cas9-edited BrrTCP4b turnip(Brassica rapa var.rapa)plants.However,the underlying molecular mechanism remains to be uncovered.In this study,we performed the Y2H screen using BrrTCP4b as the bait,which unveiled an interaction between BrrTCP4b and BrrTTG1,a pivotal WD40-repeat protein transcription factor in the MYB-bHLH-WD40(MBW)complex.This physical interaction was further validated through bimolecular luciferase complementation and co-immunoprecipitation.Furthermore,it was found that the interaction between BrrTCP4b and BrrTTG1 could inhibit the activity of MBW complex,resulting in decreased expression of BrrGL2,a positive regulator of trichomes development.In contrast,AtTCP4 is known to regulate trichomes development by interacting with AtGL3 in Arabidopsis thaliana.Overall,this study revealed that BrrTCP4b is involved in trichome development by interacting with BrrTTG1 in turnip,indicating a divergence from the mechanisms observed in model plant A.thaliana.The findings contribute to our understanding of the regulatory mechanisms governing trichome development in the non-model plants turnip.
基金National Natural Science Foundation of China(32160261)the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0502)Science and Technology Program of Xizang Autonomous Region(XZ202001YD0008C).
文摘Descriptions of floral traits based on the visual capabilities of pollinators would advance our understanding of flower evolution and plantepollinator relationships.One such trait is the contrasting UV bullseye color pattern,which is invisible to human eyes but can be perceived by bee pollinators.However,it remains largely unknown how UV bullseye size affects male and female reproductive fitness.We examined UV bullseye patterns in the dioecious Herpetospermum pedunculosum,and quantified the effects of UV bullseye size on male and female fitness.Both UV bullseye size and flower size were larger in male flowers than in female flowers.The dominant pollinators of H.pedunculosum were bees,which could perceive the UV bullseye pattern.Bee pollinators exhibited a preference for male flowers with nectar rewards,and visited a greater number of male flowers on plants with a larger UV bullseye.Male reproductive fitness was found to decrease in plants with larger UV bullseyes,likely due to the high rate of intra-plant pollen transfer.Rewardless female flowers were less attractive to bee pollinators,resulting in pollen limitation of seed production.Female flowers with moderate UV bullseye size produced more seeds.Our results suggest that UV bullseye is subject to different selection via male and female fitness of H.pedunculosum with deceptive pollination,and large UV bullseye is generally not favored.This research is the first to examine the relationship between UV bullseye size and plant reproductive success,highlighting that floral evolution should be investigated from the pollinator's eye in future research.