Glacier inventories serve as critical baseline data for understanding the impacts of climate change on glaciers.The present study maps the outlines of glaciers in the Chandra-Bhaga Basin(western Himalaya)for the years...Glacier inventories serve as critical baseline data for understanding the impacts of climate change on glaciers.The present study maps the outlines of glaciers in the Chandra-Bhaga Basin(western Himalaya)for the years 1993,2000,2010,and 2019 using Landsat Thematic Mapper(TM),Enhanced Thematic Mapper(ETM),and Operational Land Imager(OLI)datasets.A total of 251 glaciers,each having an area above 0.5 km^(2),were identified,which include 216 clean-ice and 35 debris-covered glaciers.Area changes are estimated for three periods:1993-2000,2000-2010,and 2010-2019.The total glacierized area was 996±62 km^(2) in 1993,which decreased to 973±70 km^(2) in 2019.The mean rate of glacier area loss was higher in the recent decade(2010-2019),at 0.036 km^(2),compared to previous decades(0.029 km^(2) in 2000-2010 and 0.025 km^(2) in 1993-2000).Supraglacial debris cover changes are also mapped over the period of 1993 and 2019.It is found that the supraglacial debris cover increased by 14.12±2.54 km^(2)(15.2%)during 1993-2019.Extensive field surveys on Chhota Shigri,Panchi II,Patsio,Hamtah,Mulkila,and Yoche Lungpa glaciers were carried out to validate the glacier outlines and supraglacial debris cover estimated using satellite datasets.Controls of various morphological parameters on retreat were also analyzed.It is observed that small,clean ice,south oriented glaciers,and glaciers with proglacial lakes are losing area at faster rates than other glaciers in the basin.展开更多
AIM:To quantitatively measure ocular morphological parameters of guinea pig with Python technology.METHODS:Thirty-six eyeballs of eighteen 3-weekold guinea pigs were measured with keratometer and photographed to obtai...AIM:To quantitatively measure ocular morphological parameters of guinea pig with Python technology.METHODS:Thirty-six eyeballs of eighteen 3-weekold guinea pigs were measured with keratometer and photographed to obtain the horizontal,coronal,and sagittal planes respectively.The corresponding photo pixels-actual length ratio was acquired by a proportional scale.The edge coordinates were identified artificially by ginput function.Circle and conic curve fitting were applied to fit the contour of the eyeball in the sagittal,coronal and horizontal view.The curvature,curvature radius,eccentricity,tilt angle,corneal diameter,and binocular separation angle were calculated according to the geometric principles.Next,the eyeballs were removed,canny edge detection was applied to identify the contour of eyeball in vitro.The results were compared between in vivo and in vitro.RESULTS:Regarding the corneal curvature and curvature radius on the horizontal and sagittal planes,no significant differences were observed among results in vivo,in vitro,and the keratometer.The horizontal and vertical binocular separation angles were 130.6°±6.39°and 129.8°±9.58°respectively.For the corneal curvature radius and eccentricity in vivo,significant differences were observed between horizontal and vertical planes.CONCLUSION:The Graphical interface window of Python makes up the deficiency of edge detection,which requires too much definition in Matlab.There are significant differences between guinea pig and human beings,such as exotropic eye position,oblique oval eyeball,and obvious discrepancy of binoculus.This study helps evaluate objectively the ocular morphological parameters of small experimental animals in emmetropization research.展开更多
The double flower developmental process is regulated via a complex transcriptional regulatory network.To understand this highly dynamic and complex developmental process of Dianthus spp.,we performed a comparative ana...The double flower developmental process is regulated via a complex transcriptional regulatory network.To understand this highly dynamic and complex developmental process of Dianthus spp.,we performed a comparative analysis of floral morphology and transcriptome dynamics in simple flowers and double flowers.We found that the primordium of double flowers of‘X’was larger in size compared to that of simple flowers of‘L’in Dianthus chinensis.RNA-seq and Weighted Gene Co-expression Network Analysis(WGCNA)during flower development,identified stage-specific gene network modules.Expression analysis by RNA-seq indicated that a group of genes related to floral meristem identity,primordia position and polarity were highly expressed in double flowers genotypes compared to simple flowers genotypes,suggesting their roles in double-petal formation.A total of 21 DEGs related to petal number were identified between simple and double flowers.The experiments of in situ hybridization revealed that DcaAP2L,DcaLFY and DcaUFO genes were expressed in the intra-sepal boundary and petal boundary.We proposed a potential transcriptional regulatory network for simple and double flower development.This study provides novel insights into the molecular mechanism underlying double flower formation in Dianthus spp.展开更多
Lake is an important part of the natural ecosystem, and its morphological characteristics reflect the capacity of lake regulation and storage, the strength of material migration, and the characteristics of shoreline d...Lake is an important part of the natural ecosystem, and its morphological characteristics reflect the capacity of lake regulation and storage, the strength of material migration, and the characteristics of shoreline development. In most existing studies, remote sensing images are used to quantify the morphological characteristics of lakes. However, the extraction accuracy of lake water is greatly affected by cloud cover and vegetation cover, and the inversion accuracy of lake elevation data is poor, which cannot accurately describe the response relationship of lake landscape morphology with water level change. Therefore, this paper takes Tonle Sap Lake as the research object, which is the largest natural freshwater lake in Southeast Asia. DEM is constructed based on high-resolution measured topographic data, and morphological indicators such as lake area, lake shoreline length, perimeter area ratio, longest axis length, maximum width, shoreline development index, lake shape complexity, compactness ratio and form ratio are adopted to researching the evolution law of high water overflows and low water outbursts quantitatively, and clarifying the variation characteristics of landscape morphology with water level gradient in Tonle Sap Lake. The research results have important theoretical significance for the scientific utilization of Tonle Sap Lake water resources and the protection of the lake ecosystem.展开更多
Autophagy is a cellular catabolic process characterized by the formation of double-membrane autophagosomes.Transmission electron microscopy is the most rigorous method to clearly visualize autophagic engulfment and de...Autophagy is a cellular catabolic process characterized by the formation of double-membrane autophagosomes.Transmission electron microscopy is the most rigorous method to clearly visualize autophagic engulfment and degradation.A large number of studies have shown that autophagy is closely related to the digestion,secretion,and regeneration of gastrointestinal(GI)cells.However,the role of autophagy in GI diseases remains controversial.This article focuses on the morphological and biochemical characteristics of autophagy in GI diseases,in order to provide new ideas for their diagnosis and treatment.展开更多
The maintenance of sand-fixing vegetation is important for the stability of artificial sand-fixing systems in which seed dispersal plays a key role.Based on field wind tunnel experiments using 11 common plant species ...The maintenance of sand-fixing vegetation is important for the stability of artificial sand-fixing systems in which seed dispersal plays a key role.Based on field wind tunnel experiments using 11 common plant species on the southeastern edge of the Tengger Desert,China,we studied the secondary seed dispersal in the fixed and semi-fixed sand dunes as well as in the mobile dunes in order to understand the limitations of vegetation regeneration and the maintenance of its stability.Our results indicated that there were significant variations among the selected 11 plant species in the threshold of wind speed(TWS).The TWS of Caragana korshinskii was the highest among the 11 plant species,whereas that of Echinops gmelinii was the lowest.Seed morphological traits and underlying surface could generally explain the TWS.During the secondary seed dispersal processes,the proportions of seeds that did not disperse(no dispersal)and only dispersed over short distance(short-distance dispersal within the wind tunnel test section)were significantly higher than those of seeds that were buried(including lost seeds)and dispersed over long distance(long-distance dispersal beyond the wind tunnel test section).Compared with other habitats,the mobile dunes were the most difficult places for secondary seed dispersal.Buried seeds were the easiest to be found in the semi-fixed sand dunes,whereas fixed sand dunes were the best sites for seeds that dispersed over long distance.The results of linear mixed models showed that after controlling the dispersal distance,smaller and rounder seeds dispersed farther.Shape index and wind speed were the two significant influencing factors on the burial of seeds.The explanatory power of wind speed,underlying surface,and seed morphological traits on the seeds that did not disperse and dispersed over short distance was far greater than that on the seeds that were buried and dispersed over long distance,implying that the processes and mechanisms of burial and long-distance dispersal are more complex.In summary,most seeds in the study area either did not move,were buried,or dispersed over short distance,promoting local vegetation regeneration.展开更多
Objective:To determine the relationship between teratozoospermia and sperm DNA fragmentation(SDF)in the human ejaculate.Methods:This retrospective study included 100 normozoospermic men as a control cohort(abnormal fo...Objective:To determine the relationship between teratozoospermia and sperm DNA fragmentation(SDF)in the human ejaculate.Methods:This retrospective study included 100 normozoospermic men as a control cohort(abnormal forms>14%),210 patients with a high level of abnormal forms(≤4%)and 65 patients presenting with a moderate level of abnormal forms(>4%to≤14%)based on the World Health Organization definitions.Sperm morphology was assessed using bright field microscopy.Sperm DNA fragmentation was assessed using the sperm chromatin dispersion assay.Non-parametric analyses were conducted to examine the relationship between abnormal sperm morphology and sperm DNA fragmentation;receiver operating characteristic(ROC)analyses were conducted to assess sensitivity and specificity of this relationship.Results:A correlation analysis revealed that the higher the proportion of abnormal spermatozoa in the ejaculate,the higher the level of SDF(Spearman's Rho=-0.230;P<0.001).Significant differences in the proportion of SDF were found when all cohorts were compared(P<0.001);these significant differences were also retained when the different cohorts were compared pairwise.ROC analysis showed a moderate but significant predictive value for SDF to differentiate patients with different levels of teratozoospemia.Conclusions:Although analysis of a more continuous range of values for teratozoospermia would help further clarify any causal relationship with SDF,there is clearly a synergistic or coincident affiliation between these variables that needs to be acknowledged by the clinician when interpreting the spermiogram.展开更多
The first record of abnormal body coloration in Sebastes koreanus Kim and Lee,1994,from the Yellow Sea of China,was documented based on morphological characteristics and DNA barcoding.The two rockfish specimens were c...The first record of abnormal body coloration in Sebastes koreanus Kim and Lee,1994,from the Yellow Sea of China,was documented based on morphological characteristics and DNA barcoding.The two rockfish specimens were collected from the coastal waters of Qingdao,China,and the whole body and all fins of them were red.Of the two red-colored rockfish,there were tiny deep red spots on each fin,2 red radial stripes behind and below the eyes and 1 large deep red blotch on the opercula,while the similar stripe and spot patterns are also present in the S.koreanus specimens with normal body coloration.The countable characteristics of the two specimens are in the range of the morphometry of S.koreanus.To further clarify the species identity and taxonomic status of the two specimens,DNA barcode analysis was carried out.The genetic distance between the red-colored rockfish and S.koreanus was 0,and the minimum net genetic distances between the red-colored rockfish and other Sebastes species except for S.koreanus were 3.0%,which exceeds the threshold of species delimitation.The phylogenetic analysis showed that the DNA barcoding sequences of the two red-colored rockfish clustered with the S.koreanus sequences.The above results of DNA barcode analysis also support that the two red-colored rockfish could be identified as the species of S.koreanus.The mechanism of color variation in S.koreanus is desirable for further research and the species could be an ideal model to study the color-driven speciation of the rockfishes.展开更多
Alpine revegetated dunes have been barely researched in terms of morphological change and migration within its regional aeolian environments. To reveal the sand-fixing and land-reforming mechanisms of artificial veget...Alpine revegetated dunes have been barely researched in terms of morphological change and migration within its regional aeolian environments. To reveal the sand-fixing and land-reforming mechanisms of artificial vegetation, we observed the morphology and migration of four dunes with four revegetated types(Hippophae rhamnoides Linn., Salix cheilophila Schneid., Populus simonii Carr., and Artemisia desertorum Spreng.) using unpiloted aerial vehicle images and GPS(global positioning system) mapping in 2009 and 2018. Spatial analysis of GIS(geographic information system) revealed that the revegetated dunes exhibited a steady progression from barchan dune shapes to dome or ribbons shapes mainly through knap planation, wing amplification, and slope symmetrization. Generally, conditions of northern aspects, smaller slope degree, and larger altitude of unvegetated dunes would suffer more serious wind erosion. The southward movement of dune wings with a migration speed of 2.0–5.0 m/a and the alternating motion of sand ridges in eastwestern directions led greater stability in revegetated dunes. The moving distances of revegetated dunes remarkably changed in patterns of quadratic or linear function with depositional depth. Compared with unvegetated dunes, the near-surface wind velocity of revegetated dunes decreased by 20%–30%, which led to heavy accumulation in low-flat dunes and erosion in high-steep dunes, but all vegetation species produced obvious sand-fixing benefits(100%–450% and 3%–140% in the lower and higher dune scales of revegetated dunes, respectively) with decreasing sand transport rates and increasing coverages. In practice, the four vegetation species effectively anchored mobile dunes by adapting to regional aeolian environment. However, future revegetation efforts should consider optimizing dune morphology by utilizing H. rhamnoides as a pioneer plant, S. cheilophila and P.microphylla in windward and northward dune positions, and A. desertorum in a sand accumulative southward position. Also, we should adjust afforestation structure and replant some shrub or herbs in the higher revegetated dunes to prevent fixed dune activation and southward expansion.展开更多
A comprehensive understanding of spatial distribution and clustering patterns of gravels is of great significance for ecological restoration and monitoring.However,traditional methods for studying gravels are low-effi...A comprehensive understanding of spatial distribution and clustering patterns of gravels is of great significance for ecological restoration and monitoring.However,traditional methods for studying gravels are low-efficiency and have many errors.This study researched the spatial distribution and cluster characteristics of gravels based on digital image processing technology combined with a self-organizing map(SOM)and multivariate statistical methods in the grassland of northern Tibetan Plateau.Moreover,the correlation of morphological parameters of gravels between different cluster groups and the environmental factors affecting gravel distribution were analyzed.The results showed that the morphological characteristics of gravels in northern region(cluster C)and southern region(cluster B)of the Tibetan Plateau were similar,with a low gravel coverage,small gravel diameter,and elongated shape.These regions were mainly distributed in high mountainous areas with large topographic relief.The central region(cluster A)has high coverage of gravels with a larger diameter,mainly distributed in high-altitude plains with smaller undulation.Principal component analysis(PCA)results showed that the gravel distribution of cluster A may be mainly affected by vegetation,while those in clusters B and C could be mainly affected by topography,climate,and soil.The study confirmed that the combination of digital image processing technology and SOM could effectively analyzed the spatial distribution characteristics of gravels,providing a new mode for gravel research.展开更多
Epitaxial graphene grown on silicon carbide(Si C/graphene)is a promising solution for achieving a highprecision quantum Hall resistance standard.Previous research mainly focused on the quantum resistance metrology of ...Epitaxial graphene grown on silicon carbide(Si C/graphene)is a promising solution for achieving a highprecision quantum Hall resistance standard.Previous research mainly focused on the quantum resistance metrology of n-type Si C/graphene,while a comprehensive understanding of the quantum resistance metrology behavior of graphene with different doping types is lacking.Here,we fabricated both n-and p-type Si C/graphene devices via polymer-assisted molecular adsorption and conducted systematic magneto-transport measurements in a wide parameter space of carrier density and temperature.It is demonstrated that n-type devices show greater potential for development of quantum resistance metrology compared with p-type devices,as evidenced by their higher carrier mobility,lower critical magnetic field for entering quantized Hall plateaus,and higher robustness of the quantum Hall effect against thermal degeneration.These discrepancies can be reasonably attributed to the weaker scattering from molecular dopants for n-type devices,which is further supported by the analyses on the quantum interference effect in multiple devices.These results enrich our understanding of the charged impurity on electronic transport performance of graphene and,more importantly,provide a useful reference for future development of graphene-based quantum resistance metrology.展开更多
Sesame is Burkina Faso’s second essential agricultural export after cotton. It’s consequently a supply of income for producers and foreign exchange for the country. However, sesame production is characterized by low...Sesame is Burkina Faso’s second essential agricultural export after cotton. It’s consequently a supply of income for producers and foreign exchange for the country. However, sesame production is characterized by low average yields of about 538 kg·ha<sup>-1</sup> at the farmer’s field as compared to the potential yield of the improved varieties (1500 - 2000 kg·ha<sup>-1</sup>). Fungal diseases are some of the major constraints to sesame production in Burkina Faso. The present study contributes to the development of means to control pathogenic fungi of this crop, which are responsible for significant losses. The objective is to identify the fungi associated with diseased sesame plant samples. To this end, 149 samples of diseased sesame plants were collected from different production sites located in three agro-climatic zones of the country. The analysis of the samples according to the blotting paper method, based on the morphological characteristics of the fungi, allowed the identification of 18 genera with prevalence rates from 2.68% to 97.98%. The most frequently identified genera were Macrophomina (97.98%), Cercospora (86.57%), Fusarium (85.23%), Phoma (62.41%) and Colletotrichum (61.07%). The results also showed a variable distribution of fungi according to the agro-climatic zone with the predominance of Macrophomina in all three zones. Molecular identification by DNA sequencing of 120 isolates belonging to the different fungi detected allowed the identification of 25 species of which the most representative were Macrophomina phaseolina, Cercospora sesami, Corynespora cassiicola, Alternaria simsimi, Alternaria porri, Fusarium oxysporum, F. fujikuroi, F. equiseti, Colletotrichum capsici, and C. gloesporiodes. The present study showed that diseased sesame plants collected from different production sites in Burkina Faso housed several species of fungi. The fungi presence in diseased plants indicates the need to inform and raise the stakeholders’ awareness about the phytosanitary problems of sesame, but also to develop effective and appropriate control methods against these crop pathogens in Burkina Faso.展开更多
This study set out to look into the palyno-morphological characteristics of specific allergenic species from diverse plant families in Samarkand, Uzbekistan. Six different species i.e. Betula pendula, Fraxinus pennsyl...This study set out to look into the palyno-morphological characteristics of specific allergenic species from diverse plant families in Samarkand, Uzbekistan. Six different species i.e. Betula pendula, Fraxinus pennsylvanica, Magnolia × soulangeana, Pinus brutia var. eldarica, Populus alba, Quercus robur were collected, pressed, identified, and then examined under a microscope. Under light microscope, both quantitative and qualitative characteristics of the pollen grains were recorded, including pollen type, pollen size, pollen shape (polar and equatorial view), P/E ratio, mesocolpium distance, exine thickness, colpi type, colpi length, and width. It was found that a warm spring in Uzbekistan causes an early commencement of the vegetative and dusting phases, in contrast to the climatic circumstances of the researched entities’ motherland (cold spring). Studies in aeropalinology and morphology enable the resolution of numerous environmental issues. The findings highlighted the importance of pollen morphology as an identifying aid and showed how the tested species’ palynological characteristics varied. In order to promote future phylogenetic description of the Uzbekistan flora, the current study may help us better understand the palynomorphological traits of native plants. This essay only briefly and inadequately addresses these issues. The information gathered will be used to make an atlas of allergic plants in Samarkand and an electronic warning system for the general public about the spread of pollen from the city’s allergenic plants in the future.展开更多
Two new species of Polyalthiopsis(Annonaceae),P.nigra Y.H.Tan & Bin Yang from Guangxi and Yunnan Provinces and P.xui Y.H.Tan & Bin Yang from Yunnan Province,are described and illustrated.P.nigra is morphologic...Two new species of Polyalthiopsis(Annonaceae),P.nigra Y.H.Tan & Bin Yang from Guangxi and Yunnan Provinces and P.xui Y.H.Tan & Bin Yang from Yunnan Province,are described and illustrated.P.nigra is morphologically similar to P.chinensis in having narrowly elliptic-oblong,lemon to yellowish green petals,but differs by having obovoid monocarps,a higher number of leaf secondary veins,leaf blades usually widest above the middle,and a lower ratio of leaf blade length to width.P.xui is morphologically similar to P.floribunda in having axillary inflorescences,1-3(-4) flowers,elliptic leaves,and ellipticovate petals,but differs in the numbers of carpels per flower and ovules per carpel.The molecular phylogenetic analysis using five plastid markers confirm that the two new species belong to the genus Polyalthiopsis and show clear interspecific divergences between P.nigra and P.xui and between them and other species in the genus.Detailed descriptions,colored photographs,and habitat and distribution data for the two new species are provided.In addition,the fruit morphology of P.chinensis is described for the first time,based on living collections.Geographical distributions and a diagnostic key for all Polyalthiopsis species are also presented.展开更多
Rice,the main food crop in China,has been sporadically reported to suffer from weedy rice infestation.However,the overall occurrence and distribution pattern of Chinese weedy rice remains unclear because a systematic ...Rice,the main food crop in China,has been sporadically reported to suffer from weedy rice infestation.However,the overall occurrence and distribution pattern of Chinese weedy rice remains unclear because a systematic survey has not been conducted.In order to reveal the infestation of Chinese weedy rice,a field survey was conducted in 999 sampling sites all over the rice-growing regions in China from 2009 to 2016 using seven-scale visual scoring of the level of weed infestation.Weedy rice was found 39%occurrence incidence in a total of 387 sites.The sampling sites with 50%or higher overall weedy rice infestation index mainly radiated from Jiangsu,Heilongjiang,Ningxia and Guangdong to the whole East China,Northeast China,Northwest China and South China.A total of 45 morphological characters from 287 populations(collected simultaneously with the field survey)out of those occurred sites were observed and analyzed using multivariate analysis in common gardens with the same cultivation conditions in 2017 and 2019.Canonical correlation analysis showed that 45 morphological characters were significantly related to the latitude,mean temperature,minimum temperature,precipitation and mean diurnal range factors.The 287 weedy rice populations were divided into three morphological groups with climate-dependent geographical differentiation:strong tiller type only in Jiangsu,large leaf type in South China and Central China and large grain type mainly in North China.Weedy rice seriously infested rice fields and had a geography,climate and cultivated rice type-dependent morphological and biotype differentiation in China.It is suggested to pay attention to the harmfulness of weedy rice and adopt comprehensive control strategies.展开更多
The rhynchonellide brachiopod Dzieduszyckia Siemiradzki is widely distributed in the Lower Famennian strata,and exhibits a wide range of morphological variations among populations.1272 autochthonous Devonian Rongxian ...The rhynchonellide brachiopod Dzieduszyckia Siemiradzki is widely distributed in the Lower Famennian strata,and exhibits a wide range of morphological variations among populations.1272 autochthonous Devonian Rongxian Dzieduszyckia fossils were collected from three populations in South China,namely the Dazhai,Dalong,and Longmi sections.A series of quantitative morphological analyses were conducted to understand the morphological variation among populations and identify the triggers responsible for such variations.The results show that the Dazhai population differs significantly in morphospace from the Dalong and Longmi populations,while the latter two exhibit more similar morphological features,suggesting that geographic distribution may play a key role in affecting Dzieduszyckia morphology.The Longmi population shows a distinct morphospace from the Dazhai population and an overlapped morphospace with the Dalong population,indicating that habitat may not be the controlling factor.Lastly,the Dazhai and Dalong populations share some morphological similarities,but the Dazhai and Longmi populations occupy completely different morphospaces,indicating that evolution had a greater impact on phenotypic divergence than habitat.Our findings suggest that geographic distribution is the predominant factor influencing the morphological variation of Dzieduszyckia,while evolution and living habitat are less significant,the former of which might play a more important role.展开更多
The marine and freshwater Hildenbrandia samples were collected from diverse locations of China and Japan,and mor-phological characterization and molecular phylogenetic analysis were conducted on these samples.Morpholo...The marine and freshwater Hildenbrandia samples were collected from diverse locations of China and Japan,and mor-phological characterization and molecular phylogenetic analysis were conducted on these samples.Morphological measurements of freshwater specimens were consistent with the results of H.jigongshanensis,whereas cell dimensions of marine specimens were slightly larger than those of widely distributed H.rubra and H.crouanii.Phylogenetic trees based on rbcL,psbA and UPA sequences were consistent.Freshwater specimens collected in this study formed an independent clade with H.jigongshanensis supported by high values.Species attribution was confirmed further by the similar ITS2 secondary structures among the samples of H.jigongshan-ensis.It was found that the intraspecific divergence of rbcL gene in H.jigongshanensis was smaller than other two freshwater species H.rivularis and H.angolensis.Phylogenetic trees showed that marine specimens in this study grouped together with H.rubra samples of North America,and were different with the H.rubra samples of Europe.Combining the comparison results of CBC numbers in ITS2 secondary structure,we propose the marine samples collected in this study to be a new species Hildenbrandia qingdaoensis sp.nov.The separation of the marine and freshwater specimens was supported by the rbcL,UPA and psbA phylogeny as well as ITS2 se-condary structure inference.Biogeographical reconstruction showed the ancestor of freshwater Hildenbrandia might derive from South America and dispersed from North America to Europe and then to Asian countries,which needs to be verified further with more sam-ples and molecular evidences from South America.展开更多
Many attentions have been previously focused to identify the multiple biochemical components related to tea quality and health benefits,however, the natural variation of biochemical components present in tea germplasm...Many attentions have been previously focused to identify the multiple biochemical components related to tea quality and health benefits,however, the natural variation of biochemical components present in tea germplasm has not been adequately evaluated. In this study, the main biochemical components, leaf morphological and yield characteristics were evaluated for four rounds of tea leaves in a panel of 87 elite tea cultivars suitable for black, green, or oolong tea. Significant variations were observed among the tea cultivars, as well as seasonal differences in the levels of the free amino acid(FAA), caffeine(CAF), tea polyphenols(TP), water extract(WE) and TP to FAA ratio(TP/FAA). Results showed that the average levels of FAA showed a seasonal change, with the highest level of 4.0% in the 1st spring tea in the cultivars suitable for green tea and the lowest of 3.2% in summer tea in the cultivars suitable for black tea. The average CAF content was highest 3.2% in the cultivars suitable for oolong tea in the 1st spring and the lowest 2.5% in the cultivars suitable for green tea in summer. Limited seasonal and varietal variations were noticed in the average levels of WE among the three categories of tea. In addition, significant natural variation of the morphological characteristics, bud length varying from 2.5 cm to 8.7 cm, bud density from 190.3 buds · m-2to 1 730.3 buds · m-2, mature leaves biomass from 128.4 kg · hm-2to 2 888.4 kg · hm-2, and yield component traits of 100 buds(one bud with two leaves) dry weight from 3.7 g to37.7 g, tea yield/round from 444.6 kg · hm-2to 905.3 kg · hm-2, were observed. The aim of our evaluation was not only to identify the advantages of seasonal and clonal variations but also to provide a new viewpoint for their further application. Representative accessions were selected from the germplasm to promote the establishment of an inherent biochemical constituent expressing the quality of black, green, and oolong tea. The findings might be utilized to establish early selection criteria to enhance the tea breeding and production program.展开更多
In the last two decades,the Yangtze Estuary has undergone significant changes under the influence of reduced sediment inflow and estuary engineering.This study investigates the influence of floods and typhoons on sedi...In the last two decades,the Yangtze Estuary has undergone significant changes under the influence of reduced sediment inflow and estuary engineering.This study investigates the influence of floods and typhoons on sediment concentration and the morphological evolution of shoals and channels in the Yangtze Estuary.The analysis is conducted through the utilization of topographic data measured pre-and post-flood events and observations of hydro-sedimentary changes during typhoons.By using a generalized estuary mathematical model,this study examines the interplay between varying tidal ranges,tidal divisions,runoff volumes,and regulation projects on the erosion and deposition of shoals and channels in bifurcated estuaries.The results show that due to the implementation of river and waterway regulation projects,the impact of the 2020 flood on the main channel and shoal was significantly less than that of the1998 flood.The swing amplitude of the South Branch main channel decreased.However,local river sections such as the Southern Waterway of Baimao Shoal exhibited erosion.During typhoons,sediment concentration in the 20 cm above the bottom increased significantly and was closely related to wave processes,with a weakened correlation to tidal dynamics.After typhoons,high shoals in South Passage above 0 m were silted up,while the terrain on one side of the tail of Jiuduan Shoal in the downstream deep-water area was generally scoured due to strong wave action.The generalized mathematical model of the bifurcated estuary revealed that M2 tidal component contributed most to the ero sion and deposition evolution of estuary shoals and channels,with floods exhibiting characteristics of sedime ntation on shoals and erosion on channels.With the implementation of a branch rectification project,branch resistance increased,diversion decreased,and the riverbed changed from pre-project erosion to post-project sedimentation,with an increase in erosion in non-project branches.展开更多
Taxonomic uncertainties of rare species often hinder effective prioritization for conservation.One such taxonomic uncertainty is the 90-year-old enigma of Fagus chienii.F.chienii was previously only known from the typ...Taxonomic uncertainties of rare species often hinder effective prioritization for conservation.One such taxonomic uncertainty is the 90-year-old enigma of Fagus chienii.F.chienii was previously only known from the type specimens collected in 1935 in Pingwu County of Sichuan Province,China,and has long been thought to be on the verge of extinction.However,morphological similarities to closely related Fagus species have led many to question the taxonomic status of F.chienii.To clarify this taxonomic uncertainty,we used the newly collected samples to reconstruct a molecular phylogeny of Chinese Fagus species against the phylogenetic backbone of the whole genus using seven nuclear genes.In addition,we examined nine morphological characters to determine whether F.chienii is morphologically distinct from its putatively closest relatives(F.hayatae,F.longipetiolata,and F.lucida).Both morphological and phylogenetic analyses indicated that F.chienii is conspecific with F.hayatae.We recommended that F.chienii should not be treated as a separate species in conservation management.However,conservation strategies such as in situ protection and ex situ germplasm preservation should be adopted to prevent the peculiar“F.chienii”population from extinction.展开更多
基金We also extend our gratitude to the Glaciology Group,Jawaharlal Nehru University for providing necessary support for this research.MFA acknowledges the grants from SERB(CRG/2020/004877)and MOES/16/19/2017-RDEAS projects.SV and MFA express appreciation for the support from ISRO/RES/4/690/21-22 project.
文摘Glacier inventories serve as critical baseline data for understanding the impacts of climate change on glaciers.The present study maps the outlines of glaciers in the Chandra-Bhaga Basin(western Himalaya)for the years 1993,2000,2010,and 2019 using Landsat Thematic Mapper(TM),Enhanced Thematic Mapper(ETM),and Operational Land Imager(OLI)datasets.A total of 251 glaciers,each having an area above 0.5 km^(2),were identified,which include 216 clean-ice and 35 debris-covered glaciers.Area changes are estimated for three periods:1993-2000,2000-2010,and 2010-2019.The total glacierized area was 996±62 km^(2) in 1993,which decreased to 973±70 km^(2) in 2019.The mean rate of glacier area loss was higher in the recent decade(2010-2019),at 0.036 km^(2),compared to previous decades(0.029 km^(2) in 2000-2010 and 0.025 km^(2) in 1993-2000).Supraglacial debris cover changes are also mapped over the period of 1993 and 2019.It is found that the supraglacial debris cover increased by 14.12±2.54 km^(2)(15.2%)during 1993-2019.Extensive field surveys on Chhota Shigri,Panchi II,Patsio,Hamtah,Mulkila,and Yoche Lungpa glaciers were carried out to validate the glacier outlines and supraglacial debris cover estimated using satellite datasets.Controls of various morphological parameters on retreat were also analyzed.It is observed that small,clean ice,south oriented glaciers,and glaciers with proglacial lakes are losing area at faster rates than other glaciers in the basin.
基金Supported by the National Natural Science Foundation of China(No.81400428)Self-selected Projects of Shanghai Children’s Hospital(No.2020R124)Shanghai Children’s Hospital Hospital-level Project Clinical Research Cultivation Special Focus Project(No.2021YLYZ03).
文摘AIM:To quantitatively measure ocular morphological parameters of guinea pig with Python technology.METHODS:Thirty-six eyeballs of eighteen 3-weekold guinea pigs were measured with keratometer and photographed to obtain the horizontal,coronal,and sagittal planes respectively.The corresponding photo pixels-actual length ratio was acquired by a proportional scale.The edge coordinates were identified artificially by ginput function.Circle and conic curve fitting were applied to fit the contour of the eyeball in the sagittal,coronal and horizontal view.The curvature,curvature radius,eccentricity,tilt angle,corneal diameter,and binocular separation angle were calculated according to the geometric principles.Next,the eyeballs were removed,canny edge detection was applied to identify the contour of eyeball in vitro.The results were compared between in vivo and in vitro.RESULTS:Regarding the corneal curvature and curvature radius on the horizontal and sagittal planes,no significant differences were observed among results in vivo,in vitro,and the keratometer.The horizontal and vertical binocular separation angles were 130.6°±6.39°and 129.8°±9.58°respectively.For the corneal curvature radius and eccentricity in vivo,significant differences were observed between horizontal and vertical planes.CONCLUSION:The Graphical interface window of Python makes up the deficiency of edge detection,which requires too much definition in Matlab.There are significant differences between guinea pig and human beings,such as exotropic eye position,oblique oval eyeball,and obvious discrepancy of binoculus.This study helps evaluate objectively the ocular morphological parameters of small experimental animals in emmetropization research.
基金supported by funding from National Natural Science Foundation of China(Grant Nos.32002074 and 31872135)China Postdoctoral Science Foundation(Grant No.2021M693445)。
文摘The double flower developmental process is regulated via a complex transcriptional regulatory network.To understand this highly dynamic and complex developmental process of Dianthus spp.,we performed a comparative analysis of floral morphology and transcriptome dynamics in simple flowers and double flowers.We found that the primordium of double flowers of‘X’was larger in size compared to that of simple flowers of‘L’in Dianthus chinensis.RNA-seq and Weighted Gene Co-expression Network Analysis(WGCNA)during flower development,identified stage-specific gene network modules.Expression analysis by RNA-seq indicated that a group of genes related to floral meristem identity,primordia position and polarity were highly expressed in double flowers genotypes compared to simple flowers genotypes,suggesting their roles in double-petal formation.A total of 21 DEGs related to petal number were identified between simple and double flowers.The experiments of in situ hybridization revealed that DcaAP2L,DcaLFY and DcaUFO genes were expressed in the intra-sepal boundary and petal boundary.We proposed a potential transcriptional regulatory network for simple and double flower development.This study provides novel insights into the molecular mechanism underlying double flower formation in Dianthus spp.
文摘Lake is an important part of the natural ecosystem, and its morphological characteristics reflect the capacity of lake regulation and storage, the strength of material migration, and the characteristics of shoreline development. In most existing studies, remote sensing images are used to quantify the morphological characteristics of lakes. However, the extraction accuracy of lake water is greatly affected by cloud cover and vegetation cover, and the inversion accuracy of lake elevation data is poor, which cannot accurately describe the response relationship of lake landscape morphology with water level change. Therefore, this paper takes Tonle Sap Lake as the research object, which is the largest natural freshwater lake in Southeast Asia. DEM is constructed based on high-resolution measured topographic data, and morphological indicators such as lake area, lake shoreline length, perimeter area ratio, longest axis length, maximum width, shoreline development index, lake shape complexity, compactness ratio and form ratio are adopted to researching the evolution law of high water overflows and low water outbursts quantitatively, and clarifying the variation characteristics of landscape morphology with water level gradient in Tonle Sap Lake. The research results have important theoretical significance for the scientific utilization of Tonle Sap Lake water resources and the protection of the lake ecosystem.
基金Supported by the National Natural Science Foundation of China,No.81900533Science and Technology Project of Henan Science and Technology Department,No.232102520032。
文摘Autophagy is a cellular catabolic process characterized by the formation of double-membrane autophagosomes.Transmission electron microscopy is the most rigorous method to clearly visualize autophagic engulfment and degradation.A large number of studies have shown that autophagy is closely related to the digestion,secretion,and regeneration of gastrointestinal(GI)cells.However,the role of autophagy in GI diseases remains controversial.This article focuses on the morphological and biochemical characteristics of autophagy in GI diseases,in order to provide new ideas for their diagnosis and treatment.
基金supported by the Key R&D Program of Ningxia Hui Autonomous Region,China(2021BEG03008)the Natural Science Foundation of Ningxia Hui Autonomous Region,China(2021AAC03083).
文摘The maintenance of sand-fixing vegetation is important for the stability of artificial sand-fixing systems in which seed dispersal plays a key role.Based on field wind tunnel experiments using 11 common plant species on the southeastern edge of the Tengger Desert,China,we studied the secondary seed dispersal in the fixed and semi-fixed sand dunes as well as in the mobile dunes in order to understand the limitations of vegetation regeneration and the maintenance of its stability.Our results indicated that there were significant variations among the selected 11 plant species in the threshold of wind speed(TWS).The TWS of Caragana korshinskii was the highest among the 11 plant species,whereas that of Echinops gmelinii was the lowest.Seed morphological traits and underlying surface could generally explain the TWS.During the secondary seed dispersal processes,the proportions of seeds that did not disperse(no dispersal)and only dispersed over short distance(short-distance dispersal within the wind tunnel test section)were significantly higher than those of seeds that were buried(including lost seeds)and dispersed over long distance(long-distance dispersal beyond the wind tunnel test section).Compared with other habitats,the mobile dunes were the most difficult places for secondary seed dispersal.Buried seeds were the easiest to be found in the semi-fixed sand dunes,whereas fixed sand dunes were the best sites for seeds that dispersed over long distance.The results of linear mixed models showed that after controlling the dispersal distance,smaller and rounder seeds dispersed farther.Shape index and wind speed were the two significant influencing factors on the burial of seeds.The explanatory power of wind speed,underlying surface,and seed morphological traits on the seeds that did not disperse and dispersed over short distance was far greater than that on the seeds that were buried and dispersed over long distance,implying that the processes and mechanisms of burial and long-distance dispersal are more complex.In summary,most seeds in the study area either did not move,were buried,or dispersed over short distance,promoting local vegetation regeneration.
文摘Objective:To determine the relationship between teratozoospermia and sperm DNA fragmentation(SDF)in the human ejaculate.Methods:This retrospective study included 100 normozoospermic men as a control cohort(abnormal forms>14%),210 patients with a high level of abnormal forms(≤4%)and 65 patients presenting with a moderate level of abnormal forms(>4%to≤14%)based on the World Health Organization definitions.Sperm morphology was assessed using bright field microscopy.Sperm DNA fragmentation was assessed using the sperm chromatin dispersion assay.Non-parametric analyses were conducted to examine the relationship between abnormal sperm morphology and sperm DNA fragmentation;receiver operating characteristic(ROC)analyses were conducted to assess sensitivity and specificity of this relationship.Results:A correlation analysis revealed that the higher the proportion of abnormal spermatozoa in the ejaculate,the higher the level of SDF(Spearman's Rho=-0.230;P<0.001).Significant differences in the proportion of SDF were found when all cohorts were compared(P<0.001);these significant differences were also retained when the different cohorts were compared pairwise.ROC analysis showed a moderate but significant predictive value for SDF to differentiate patients with different levels of teratozoospemia.Conclusions:Although analysis of a more continuous range of values for teratozoospermia would help further clarify any causal relationship with SDF,there is clearly a synergistic or coincident affiliation between these variables that needs to be acknowledged by the clinician when interpreting the spermiogram.
基金Supported by the National Key R&D Program of China (No.2018YFD0900803)the China Agriculture Research System of MOF and MARA (No.CARS-47)the Central Public-Interest Scientific Institution Basal Research Fund (Nos.2021JC01,20603022022024)
文摘The first record of abnormal body coloration in Sebastes koreanus Kim and Lee,1994,from the Yellow Sea of China,was documented based on morphological characteristics and DNA barcoding.The two rockfish specimens were collected from the coastal waters of Qingdao,China,and the whole body and all fins of them were red.Of the two red-colored rockfish,there were tiny deep red spots on each fin,2 red radial stripes behind and below the eyes and 1 large deep red blotch on the opercula,while the similar stripe and spot patterns are also present in the S.koreanus specimens with normal body coloration.The countable characteristics of the two specimens are in the range of the morphometry of S.koreanus.To further clarify the species identity and taxonomic status of the two specimens,DNA barcode analysis was carried out.The genetic distance between the red-colored rockfish and S.koreanus was 0,and the minimum net genetic distances between the red-colored rockfish and other Sebastes species except for S.koreanus were 3.0%,which exceeds the threshold of species delimitation.The phylogenetic analysis showed that the DNA barcoding sequences of the two red-colored rockfish clustered with the S.koreanus sequences.The above results of DNA barcode analysis also support that the two red-colored rockfish could be identified as the species of S.koreanus.The mechanism of color variation in S.koreanus is desirable for further research and the species could be an ideal model to study the color-driven speciation of the rockfishes.
基金funded by the Jiangxi Provincial Natural Science Foundation (20202BABL213028)the Open Project of the State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, China (2022-KF-07)the Doctoral Scientific Research Foundation of East China University of Technology (2019052, 2019045)。
文摘Alpine revegetated dunes have been barely researched in terms of morphological change and migration within its regional aeolian environments. To reveal the sand-fixing and land-reforming mechanisms of artificial vegetation, we observed the morphology and migration of four dunes with four revegetated types(Hippophae rhamnoides Linn., Salix cheilophila Schneid., Populus simonii Carr., and Artemisia desertorum Spreng.) using unpiloted aerial vehicle images and GPS(global positioning system) mapping in 2009 and 2018. Spatial analysis of GIS(geographic information system) revealed that the revegetated dunes exhibited a steady progression from barchan dune shapes to dome or ribbons shapes mainly through knap planation, wing amplification, and slope symmetrization. Generally, conditions of northern aspects, smaller slope degree, and larger altitude of unvegetated dunes would suffer more serious wind erosion. The southward movement of dune wings with a migration speed of 2.0–5.0 m/a and the alternating motion of sand ridges in eastwestern directions led greater stability in revegetated dunes. The moving distances of revegetated dunes remarkably changed in patterns of quadratic or linear function with depositional depth. Compared with unvegetated dunes, the near-surface wind velocity of revegetated dunes decreased by 20%–30%, which led to heavy accumulation in low-flat dunes and erosion in high-steep dunes, but all vegetation species produced obvious sand-fixing benefits(100%–450% and 3%–140% in the lower and higher dune scales of revegetated dunes, respectively) with decreasing sand transport rates and increasing coverages. In practice, the four vegetation species effectively anchored mobile dunes by adapting to regional aeolian environment. However, future revegetation efforts should consider optimizing dune morphology by utilizing H. rhamnoides as a pioneer plant, S. cheilophila and P.microphylla in windward and northward dune positions, and A. desertorum in a sand accumulative southward position. Also, we should adjust afforestation structure and replant some shrub or herbs in the higher revegetated dunes to prevent fixed dune activation and southward expansion.
基金funded by the National Natural Science Foundation of China(41971226,41871357)the Major Research and Development and Achievement Transformation Projects of Qinghai,China(2022-QY-224)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA28110502,XDA19030303).
文摘A comprehensive understanding of spatial distribution and clustering patterns of gravels is of great significance for ecological restoration and monitoring.However,traditional methods for studying gravels are low-efficiency and have many errors.This study researched the spatial distribution and cluster characteristics of gravels based on digital image processing technology combined with a self-organizing map(SOM)and multivariate statistical methods in the grassland of northern Tibetan Plateau.Moreover,the correlation of morphological parameters of gravels between different cluster groups and the environmental factors affecting gravel distribution were analyzed.The results showed that the morphological characteristics of gravels in northern region(cluster C)and southern region(cluster B)of the Tibetan Plateau were similar,with a low gravel coverage,small gravel diameter,and elongated shape.These regions were mainly distributed in high mountainous areas with large topographic relief.The central region(cluster A)has high coverage of gravels with a larger diameter,mainly distributed in high-altitude plains with smaller undulation.Principal component analysis(PCA)results showed that the gravel distribution of cluster A may be mainly affected by vegetation,while those in clusters B and C could be mainly affected by topography,climate,and soil.The study confirmed that the combination of digital image processing technology and SOM could effectively analyzed the spatial distribution characteristics of gravels,providing a new mode for gravel research.
基金supported by the CAS Project for Young Scientists in Basic Research(Grant No.YSBR-046)the National Natural Science Foundation of China(Grant Nos.92165201,11974324,12104435)+4 种基金the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302800)the Anhui Initiative in Quantum Information Technologies(Grant No.AHY170000)Hefei Science Center CAS(Grant No.2020HSC-UE014)the Fundamental Research Funds for the Central Universities(Grant Nos.WK3510000013 and WK2310000104)supported by USTC Tang Scholar。
文摘Epitaxial graphene grown on silicon carbide(Si C/graphene)is a promising solution for achieving a highprecision quantum Hall resistance standard.Previous research mainly focused on the quantum resistance metrology of n-type Si C/graphene,while a comprehensive understanding of the quantum resistance metrology behavior of graphene with different doping types is lacking.Here,we fabricated both n-and p-type Si C/graphene devices via polymer-assisted molecular adsorption and conducted systematic magneto-transport measurements in a wide parameter space of carrier density and temperature.It is demonstrated that n-type devices show greater potential for development of quantum resistance metrology compared with p-type devices,as evidenced by their higher carrier mobility,lower critical magnetic field for entering quantized Hall plateaus,and higher robustness of the quantum Hall effect against thermal degeneration.These discrepancies can be reasonably attributed to the weaker scattering from molecular dopants for n-type devices,which is further supported by the analyses on the quantum interference effect in multiple devices.These results enrich our understanding of the charged impurity on electronic transport performance of graphene and,more importantly,provide a useful reference for future development of graphene-based quantum resistance metrology.
文摘Sesame is Burkina Faso’s second essential agricultural export after cotton. It’s consequently a supply of income for producers and foreign exchange for the country. However, sesame production is characterized by low average yields of about 538 kg·ha<sup>-1</sup> at the farmer’s field as compared to the potential yield of the improved varieties (1500 - 2000 kg·ha<sup>-1</sup>). Fungal diseases are some of the major constraints to sesame production in Burkina Faso. The present study contributes to the development of means to control pathogenic fungi of this crop, which are responsible for significant losses. The objective is to identify the fungi associated with diseased sesame plant samples. To this end, 149 samples of diseased sesame plants were collected from different production sites located in three agro-climatic zones of the country. The analysis of the samples according to the blotting paper method, based on the morphological characteristics of the fungi, allowed the identification of 18 genera with prevalence rates from 2.68% to 97.98%. The most frequently identified genera were Macrophomina (97.98%), Cercospora (86.57%), Fusarium (85.23%), Phoma (62.41%) and Colletotrichum (61.07%). The results also showed a variable distribution of fungi according to the agro-climatic zone with the predominance of Macrophomina in all three zones. Molecular identification by DNA sequencing of 120 isolates belonging to the different fungi detected allowed the identification of 25 species of which the most representative were Macrophomina phaseolina, Cercospora sesami, Corynespora cassiicola, Alternaria simsimi, Alternaria porri, Fusarium oxysporum, F. fujikuroi, F. equiseti, Colletotrichum capsici, and C. gloesporiodes. The present study showed that diseased sesame plants collected from different production sites in Burkina Faso housed several species of fungi. The fungi presence in diseased plants indicates the need to inform and raise the stakeholders’ awareness about the phytosanitary problems of sesame, but also to develop effective and appropriate control methods against these crop pathogens in Burkina Faso.
文摘This study set out to look into the palyno-morphological characteristics of specific allergenic species from diverse plant families in Samarkand, Uzbekistan. Six different species i.e. Betula pendula, Fraxinus pennsylvanica, Magnolia × soulangeana, Pinus brutia var. eldarica, Populus alba, Quercus robur were collected, pressed, identified, and then examined under a microscope. Under light microscope, both quantitative and qualitative characteristics of the pollen grains were recorded, including pollen type, pollen size, pollen shape (polar and equatorial view), P/E ratio, mesocolpium distance, exine thickness, colpi type, colpi length, and width. It was found that a warm spring in Uzbekistan causes an early commencement of the vegetative and dusting phases, in contrast to the climatic circumstances of the researched entities’ motherland (cold spring). Studies in aeropalinology and morphology enable the resolution of numerous environmental issues. The findings highlighted the importance of pollen morphology as an identifying aid and showed how the tested species’ palynological characteristics varied. In order to promote future phylogenetic description of the Uzbekistan flora, the current study may help us better understand the palynomorphological traits of native plants. This essay only briefly and inadequately addresses these issues. The information gathered will be used to make an atlas of allergic plants in Samarkand and an electronic warning system for the general public about the spread of pollen from the city’s allergenic plants in the future.
基金funded by the National Natural Science Foundation of China (Grants Nos.31900180 and 31970223)the Special Fund of Yunnan Fundamental Research Projects (Grant No.202101AT070058)+3 种基金the project of the Yunnan Academy of Forestry and Grassland (Grant No.KFJJ21-01)the Project of National Plant Specimen Resource Center (NPSRC) (E0117G1001)the Biodiversity Investigation Observation and Assessment Program (2019-2023) of Ministry of Ecology and Environment of Chinathe project of the Southeast Asia Biodiversity Research Institute,Chinese Academy of Sciences (Grant No.Y4ZK111B01)。
文摘Two new species of Polyalthiopsis(Annonaceae),P.nigra Y.H.Tan & Bin Yang from Guangxi and Yunnan Provinces and P.xui Y.H.Tan & Bin Yang from Yunnan Province,are described and illustrated.P.nigra is morphologically similar to P.chinensis in having narrowly elliptic-oblong,lemon to yellowish green petals,but differs by having obovoid monocarps,a higher number of leaf secondary veins,leaf blades usually widest above the middle,and a lower ratio of leaf blade length to width.P.xui is morphologically similar to P.floribunda in having axillary inflorescences,1-3(-4) flowers,elliptic leaves,and ellipticovate petals,but differs in the numbers of carpels per flower and ovules per carpel.The molecular phylogenetic analysis using five plastid markers confirm that the two new species belong to the genus Polyalthiopsis and show clear interspecific divergences between P.nigra and P.xui and between them and other species in the genus.Detailed descriptions,colored photographs,and habitat and distribution data for the two new species are provided.In addition,the fruit morphology of P.chinensis is described for the first time,based on living collections.Geographical distributions and a diagnostic key for all Polyalthiopsis species are also presented.
基金supported by the Major Scientific and Technological Project of Hainan Province,China(ZDKJ202002)the China Transgenic Organism Research and Commercialization Project(2016ZX08011-001)the National Key Research and Development Program of China(2016YFD0200805).
文摘Rice,the main food crop in China,has been sporadically reported to suffer from weedy rice infestation.However,the overall occurrence and distribution pattern of Chinese weedy rice remains unclear because a systematic survey has not been conducted.In order to reveal the infestation of Chinese weedy rice,a field survey was conducted in 999 sampling sites all over the rice-growing regions in China from 2009 to 2016 using seven-scale visual scoring of the level of weed infestation.Weedy rice was found 39%occurrence incidence in a total of 387 sites.The sampling sites with 50%or higher overall weedy rice infestation index mainly radiated from Jiangsu,Heilongjiang,Ningxia and Guangdong to the whole East China,Northeast China,Northwest China and South China.A total of 45 morphological characters from 287 populations(collected simultaneously with the field survey)out of those occurred sites were observed and analyzed using multivariate analysis in common gardens with the same cultivation conditions in 2017 and 2019.Canonical correlation analysis showed that 45 morphological characters were significantly related to the latitude,mean temperature,minimum temperature,precipitation and mean diurnal range factors.The 287 weedy rice populations were divided into three morphological groups with climate-dependent geographical differentiation:strong tiller type only in Jiangsu,large leaf type in South China and Central China and large grain type mainly in North China.Weedy rice seriously infested rice fields and had a geography,climate and cultivated rice type-dependent morphological and biotype differentiation in China.It is suggested to pay attention to the harmfulness of weedy rice and adopt comprehensive control strategies.
基金the National Natural Science Foundation of China(Grant Nos.41772015 and 41672334)。
文摘The rhynchonellide brachiopod Dzieduszyckia Siemiradzki is widely distributed in the Lower Famennian strata,and exhibits a wide range of morphological variations among populations.1272 autochthonous Devonian Rongxian Dzieduszyckia fossils were collected from three populations in South China,namely the Dazhai,Dalong,and Longmi sections.A series of quantitative morphological analyses were conducted to understand the morphological variation among populations and identify the triggers responsible for such variations.The results show that the Dazhai population differs significantly in morphospace from the Dalong and Longmi populations,while the latter two exhibit more similar morphological features,suggesting that geographic distribution may play a key role in affecting Dzieduszyckia morphology.The Longmi population shows a distinct morphospace from the Dazhai population and an overlapped morphospace with the Dalong population,indicating that habitat may not be the controlling factor.Lastly,the Dazhai and Dalong populations share some morphological similarities,but the Dazhai and Longmi populations occupy completely different morphospaces,indicating that evolution had a greater impact on phenotypic divergence than habitat.Our findings suggest that geographic distribution is the predominant factor influencing the morphological variation of Dzieduszyckia,while evolution and living habitat are less significant,the former of which might play a more important role.
基金the National Natural Science Foundation of China(Nos.41871037,31800172,32170204)the Fund for Shanxi‘1331 Project’.
文摘The marine and freshwater Hildenbrandia samples were collected from diverse locations of China and Japan,and mor-phological characterization and molecular phylogenetic analysis were conducted on these samples.Morphological measurements of freshwater specimens were consistent with the results of H.jigongshanensis,whereas cell dimensions of marine specimens were slightly larger than those of widely distributed H.rubra and H.crouanii.Phylogenetic trees based on rbcL,psbA and UPA sequences were consistent.Freshwater specimens collected in this study formed an independent clade with H.jigongshanensis supported by high values.Species attribution was confirmed further by the similar ITS2 secondary structures among the samples of H.jigongshan-ensis.It was found that the intraspecific divergence of rbcL gene in H.jigongshanensis was smaller than other two freshwater species H.rivularis and H.angolensis.Phylogenetic trees showed that marine specimens in this study grouped together with H.rubra samples of North America,and were different with the H.rubra samples of Europe.Combining the comparison results of CBC numbers in ITS2 secondary structure,we propose the marine samples collected in this study to be a new species Hildenbrandia qingdaoensis sp.nov.The separation of the marine and freshwater specimens was supported by the rbcL,UPA and psbA phylogeny as well as ITS2 se-condary structure inference.Biogeographical reconstruction showed the ancestor of freshwater Hildenbrandia might derive from South America and dispersed from North America to Europe and then to Asian countries,which needs to be verified further with more sam-ples and molecular evidences from South America.
基金jointly supported by the National Key Research and Development Program of China (Grant No. 2021YFD1000401)the National Natural Science Foundation of China (Grant No.32070376)+1 种基金the Program of Horticultural Crop Germplasm Resources in Hubei Province (Grant No. 2021DFE016)the Key Technology of Safety Production to Improve Tea Quality and Efficiency in Three Gorges Reservoir Area。
文摘Many attentions have been previously focused to identify the multiple biochemical components related to tea quality and health benefits,however, the natural variation of biochemical components present in tea germplasm has not been adequately evaluated. In this study, the main biochemical components, leaf morphological and yield characteristics were evaluated for four rounds of tea leaves in a panel of 87 elite tea cultivars suitable for black, green, or oolong tea. Significant variations were observed among the tea cultivars, as well as seasonal differences in the levels of the free amino acid(FAA), caffeine(CAF), tea polyphenols(TP), water extract(WE) and TP to FAA ratio(TP/FAA). Results showed that the average levels of FAA showed a seasonal change, with the highest level of 4.0% in the 1st spring tea in the cultivars suitable for green tea and the lowest of 3.2% in summer tea in the cultivars suitable for black tea. The average CAF content was highest 3.2% in the cultivars suitable for oolong tea in the 1st spring and the lowest 2.5% in the cultivars suitable for green tea in summer. Limited seasonal and varietal variations were noticed in the average levels of WE among the three categories of tea. In addition, significant natural variation of the morphological characteristics, bud length varying from 2.5 cm to 8.7 cm, bud density from 190.3 buds · m-2to 1 730.3 buds · m-2, mature leaves biomass from 128.4 kg · hm-2to 2 888.4 kg · hm-2, and yield component traits of 100 buds(one bud with two leaves) dry weight from 3.7 g to37.7 g, tea yield/round from 444.6 kg · hm-2to 905.3 kg · hm-2, were observed. The aim of our evaluation was not only to identify the advantages of seasonal and clonal variations but also to provide a new viewpoint for their further application. Representative accessions were selected from the germplasm to promote the establishment of an inherent biochemical constituent expressing the quality of black, green, and oolong tea. The findings might be utilized to establish early selection criteria to enhance the tea breeding and production program.
基金financially supported by the CRSRI Open Research Program (Grant No.CKWV20221007/KY)the National Natural Science Foundation of China (Grant No.51979172)+3 种基金Jiangsu Provincial Water Conservancy Technology Project (Grant Nos.2020002,2021025,and 2021029)Fundamental Research Funds for Central Public Welfare Research Institutes (Y223002)Innovation Team Project of Estuarine and Coastal Protection and Management (Grant No.Y220013)the Major Scientific Projects of the Ministry of Water Resources (Grant No.SKS-2022087)。
文摘In the last two decades,the Yangtze Estuary has undergone significant changes under the influence of reduced sediment inflow and estuary engineering.This study investigates the influence of floods and typhoons on sediment concentration and the morphological evolution of shoals and channels in the Yangtze Estuary.The analysis is conducted through the utilization of topographic data measured pre-and post-flood events and observations of hydro-sedimentary changes during typhoons.By using a generalized estuary mathematical model,this study examines the interplay between varying tidal ranges,tidal divisions,runoff volumes,and regulation projects on the erosion and deposition of shoals and channels in bifurcated estuaries.The results show that due to the implementation of river and waterway regulation projects,the impact of the 2020 flood on the main channel and shoal was significantly less than that of the1998 flood.The swing amplitude of the South Branch main channel decreased.However,local river sections such as the Southern Waterway of Baimao Shoal exhibited erosion.During typhoons,sediment concentration in the 20 cm above the bottom increased significantly and was closely related to wave processes,with a weakened correlation to tidal dynamics.After typhoons,high shoals in South Passage above 0 m were silted up,while the terrain on one side of the tail of Jiuduan Shoal in the downstream deep-water area was generally scoured due to strong wave action.The generalized mathematical model of the bifurcated estuary revealed that M2 tidal component contributed most to the ero sion and deposition evolution of estuary shoals and channels,with floods exhibiting characteristics of sedime ntation on shoals and erosion on channels.With the implementation of a branch rectification project,branch resistance increased,diversion decreased,and the riverbed changed from pre-project erosion to post-project sedimentation,with an increase in erosion in non-project branches.
基金supported by grants from the National Natural Science Foundation of China(No.31770236)the Guangxi Key Research and Development Projects(Guike AB21220057)Training Program for Academic and Technical Leaders(leading talents)in Major Disciplines of Jiangxi Province(grant to Zhiyong Zhang,20213BCJ22006)。
文摘Taxonomic uncertainties of rare species often hinder effective prioritization for conservation.One such taxonomic uncertainty is the 90-year-old enigma of Fagus chienii.F.chienii was previously only known from the type specimens collected in 1935 in Pingwu County of Sichuan Province,China,and has long been thought to be on the verge of extinction.However,morphological similarities to closely related Fagus species have led many to question the taxonomic status of F.chienii.To clarify this taxonomic uncertainty,we used the newly collected samples to reconstruct a molecular phylogeny of Chinese Fagus species against the phylogenetic backbone of the whole genus using seven nuclear genes.In addition,we examined nine morphological characters to determine whether F.chienii is morphologically distinct from its putatively closest relatives(F.hayatae,F.longipetiolata,and F.lucida).Both morphological and phylogenetic analyses indicated that F.chienii is conspecific with F.hayatae.We recommended that F.chienii should not be treated as a separate species in conservation management.However,conservation strategies such as in situ protection and ex situ germplasm preservation should be adopted to prevent the peculiar“F.chienii”population from extinction.
