Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the understory.In this study,we selected three stands typical in...Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the understory.In this study,we selected three stands typical in south China(a Cryptomeria japonica plantation,a Quercus acutissima plantation,and a mixed stand of both)and three thinning intensities to determine the best understory light environ-ment for 3-year-old Phoebe bournei seedlings.The canopy structure,understory light environment,and photosynthe-sis and growth indicators were assessed following thin-ning.Thinning improved canopy structure and understory light availability of each stand;species composition was the reason for differences in the understory light environ-ment.Under the same thinning intensity,the mixed stand had the greatest light radiation and most balanced spectral composition.P.bournei photosynthesis and growth were closely related to the light environment;all three stands required heavy thinning to create an effective and sustained understory light environment.In a suitable understory light environment,the efficiency of light interception,absorption,and use by seedlings was enhanced,resulting in a higher carbon assimilation the main limiting factor was stomatal conductance.As a shade-avoidance signal,red/far-red radia-tion is a critical factor driving changes in photosynthesis and growth of P.bournei seedlings,and a reduction increased light absorption and use capacity and height:diameter ratios.The growth advantage transformed from diameter to height,enabling seedlings to access more light.Our findings suggest that the regeneration of shade-tolerant species such as P.bournei could be enhanced if a targeted approach to thinning based on stand type was adopted.展开更多
As ubiquitous environmental contaminants,microplastics(MPs)have garnered global concern due to their persistence,bioaccumulation potential,and multifaceted threats to ecosystem health.These particles threaten terrestr...As ubiquitous environmental contaminants,microplastics(MPs)have garnered global concern due to their persistence,bioaccumulation potential,and multifaceted threats to ecosystem health.These particles threaten terrestrial ecosystems via soil contamination;however,research on their phytotoxicity remains predominantly focused on herbaceous plants.The responses of woody plants to MPs and their interspecific differences are severely unexplored.Here,two important ecological and economical tree species in southern China,Pinus massoniana(P.massoniana)and Schima superba(S.superba),were selected to explore the ecotoxicity effects of polyethylene(PE)and polypropylene(PP)MPs(the two most abundant species in the soil)on seedling growth characteristics,specific leaf area(SLA)and biomass allocation at 0%,1%,5%and 10%concentration gradients in the 120-day potted experiment.The results showed that the inhibition effect of MPs was concentration and tree species-dependent.Seedling height,basal diameter,and total biomass of P.massoniana decreased significantly with increased concentration,while S.superba showed a non-significant growth effect at 1%concentration.The SLA was generally increased,revealing that plants enhanced their light capture ability through leaf morphological plasticity to compensate for the loss of carbon assimilation.There were interspecific differences in root investment strategies:the root-shoot ratio of P.massoniana was significantly reduced by 48.43%under 10%PP treatment.In comparison,the root-shoot ratio of S.superba was significantly reduced by maintaining a higher root-shoot ratio(65.26%higher than that of P.massoniana on average)and phased resource allocation(5%concentration biomass is higher than 10%)partially alleviated the toxic pressure.Collectively,our results indicate that the ecotoxicity of MPs was mainly driven by concentration and was not correlated with type(PE/PP),while the differences in tree species response were closely related to their resource allocation strategies and morphological plasticity.These findings imply that MPs contamination can differently impact the growth and development of dominant tree species,potentially altering the structure,diversity,and function of forest ecosystems.This study systematically revealed the growth response mechanism of native common tree species to MPs pollution and provided a theoretical basis for sustainable management of plantations and toxicological risk assessment of forest ecosystems.展开更多
Daxing'an Mountains and Xiaoxing'an Mountains are the two regions of the highest hattudes in China.The tem-pera ture increase is most obvious there in the last hundred yeas,compared with other ie gions of Chin...Daxing'an Mountains and Xiaoxing'an Mountains are the two regions of the highest hattudes in China.The tem-pera ture increase is most obvious there in the last hundred yeas,compared with other ie gions of China.The forest vegetationecotone between Daxing'an Mounta ins and Xia oxing'an Mountains is bcate d be tween the latitude 48 and 53 N and longtude123 and 128 E.This ecotone is of great importa nce in study of gbbal clima te change due to its transitional fea ture of broa d-lea fconiferous mixe d forest and boreal forest.The bcation,geomorphology,climate,soi and ve ge tation types of the ecotoneare introduced in this paper.展开更多
China was one of the earliest countries to set up a system to continuously inventory natural forest resources. From the beginning of the 1970s until today, seven forest resource inventories have been carried out. This...China was one of the earliest countries to set up a system to continuously inventory natural forest resources. From the beginning of the 1970s until today, seven forest resource inventories have been carried out. This research summarizes the progress of forest continuous inventories and analyzes the existing deficiencies ofChina’s forest continuous inventory system and forest management plan inventory. As stated above, this research offers corresponding countermeasures and suggestions: establishing a sample plot system for comprehensive national forest inventory and monitoring with each province’s continuous forest inventory based on the foundation of the national sample plot system, able to develop the province as a subset of the overall province-level forest resource inventory according to the actual conditions in each province. Through annual multi-resource/multi-benefit surveying of the forests, the monitoring of forest amounts, quality, functions and benefits will be assisted in its entirety. The further integration of the forest continuous inventory and the forest management plan inventory is also discussed. This research also proposes the varied probability sampling method with sub-compartments as the basic sampling unit (or combinations of sub-compartments). This will also satisfy the requirements of ecological inventory by region.展开更多
A few soil microorganisms can convert insoluble forms of phosphorus （P） to an accessible form to increase plant yields The objectives of this study were to isolate, screen and identify the phosphobacteria, i.e., pho...A few soil microorganisms can convert insoluble forms of phosphorus （P） to an accessible form to increase plant yields The objectives of this study were to isolate, screen and identify the phosphobacteria, i.e., phosphate-solubilizing bacteria （PSB） and phosphate-mineralizing bacteria （PMB）, in some poplar plantations and to select potential microbial inoculants that could increase the P uptake by plants. Seventy four PSB strains and 138 PMB strains were preliminarily screened from 797＂colonies isolated from the rhizosphere soil of poplar by the visible decolorization in the National Botanical Research Institute＇s phosphate growth medium （NBRIP） containing a pH indicator of bromophenol and by the clear/halo zone on yeast malt agar plate, respectively. Then, based on the solubilization of Ca3（PO4）2 in liquid NBRIP medium and the mineralization of lecithin in liquid Menkina medium, 15 PS1R strains and 7 PMB strains were further determined for their abilities to solubilize Ca3（PO4）2 and to mineralize lecithin. The results showed that the 15 PSB strains exhibited inorganic P-solubilizing abilities ranging between 376.62 and 669.56 mg L-1 and the 7 PMB strains exhibited organic P-mineralizing abilities vaxying from 0.32 to 1.56 mg L-1 three days after incubation. Three of PSB strains with the highest P-solubilizing ability, named JW-JS1, JW-JS2 and JW-SX2, were all preliminarily identified as Pseudomonas ftuorescens, while two of PMB strains with the highest P-mineralizing ability, named JYZ-SD1 and JYT-JS2, were preliminarily identified as Bacillus cereus and Bacillus subtilis, respectively. All the efficient PSB and PMB strains should be further studied under both pot culture and field conditions to test their beneficial effects on poplar.展开更多
Effects of NaCI on seed germination, leaf gas exchange and seedling growth were investigated. The germination of P. tatarinowii seeds was delayed in the presence of NaCl, and was significantly inhibited when NaCl conc...Effects of NaCI on seed germination, leaf gas exchange and seedling growth were investigated. The germination of P. tatarinowii seeds was delayed in the presence of NaCl, and was significantly inhibited when NaCl concentration exceeded 17 mM （1.0 g·L^-1）. NaCl treatments induced reductions of transpiration rate, stomatal conductance and net photosynthetic rate and their reductions were significant with the increasing of NaCl concentration. However, intercellular CO2 concentration in seedling leaves under salt stress was significantly higher than that of controls. There was a significant reduction in survival, basal diameter increment and height increment witl increasing NaCl concentration 50 days after NaCl treatment, and a significant reduction in the dry weight increment of roots, stems, and leaves was also observed in the NaCl treatments. The deleterious effect on the biomass increment was more evident in the case of stems and leaves. Results from this study suggest that P. tatarinowii is sensitive to salinity stress and the salinity threshold for seedling growth might be less 34 mM （2.0 g· L^-1）.展开更多
A one-year study in a typical red soil region of southern China was conducted to determine atmospheric nitrogen (N) fluxes of typical N compounds (NH3, NH4-N, NO3-N, and NO2) and contribution of three sources (gas, ra...A one-year study in a typical red soil region of southern China was conducted to determine atmospheric nitrogen (N) fluxes of typical N compounds (NH3, NH4-N, NO3-N, and NO2) and contribution of three sources (gas, rainwater, and particles) to N deposition. From July 2003 to June 2004, the total atmospheric N deposition was 70.7 kg N ha-1, with dry deposition accounting for 75% of the total deposition. Dry NH3 deposition accounted for 73% of the dry deposition and 55% of the total deposition. Moreover, NO2 contributed 11% of the dry deposition and 8% of the total deposition. Reduced N compounds (NH4+ and NH3) were the predominate contributors, accounting for 66% of the total deposition. Therefore, atmospheric N deposition should be considered when soil acidification and critical loads of atmospheric deposition on soils are estimated.展开更多
To investigate the effects of exogenous lanthanum （La） on Alternanthera philoxeroides （Mart.） Griseb under perchlorate stress, changes in the growth and physiological parameters were investigated in solution cultu...To investigate the effects of exogenous lanthanum （La） on Alternanthera philoxeroides （Mart.） Griseb under perchlorate stress, changes in the growth and physiological parameters were investigated in solution culture experiments under controlled condi- tions. Different concentrations of La （NO3）3 were used in our study. It was shown that 0. 1 and 0.5 mg/L La3＋ alleviated the inhibition effect of perchlorate on A. philoxeroides, including relative growth yield, dry weight of different organs, leaf area and root activity. And La3＋ prevented decline in the relative chlorophyll content and chlorophyll fluorescence parameters including Fv/Fm, Fv＇/Frn＇, φPSll and ETR induced by perchlorate stress. Moreover, 0.5 mg/L La3＋ showed an optimal mitigative effect, while excess La3＋ （5.0 mg/L） led to synergistic effect on stress. Correlation analysis revealed a significant positive relationship between growth indexes and the chlorophyll fluorescence parameters, root activity and relative chlorophyll content （p〈0.05）. The results suggested that appropriate concentration of La3＋ could effectively alleviate growth inhibition and injury ofA. philoxeroides caused by perchlorate stress, and the mitigative effect of La3＋ might be achieved by improving root activity, maintaining chlorophyll content and promoting photochemical efficiency of photosystem II ofA. philoxeroides under perchlorate stress.展开更多
In the Three Gorges Area of China, soil erosion and the resultant non-point source pollution and ecological degradation have endangered agricultural ecosystems and fresh water reservoirs. Although efforts have been un...In the Three Gorges Area of China, soil erosion and the resultant non-point source pollution and ecological degradation have endangered agricultural ecosystems and fresh water reservoirs. Although efforts have been undertaken to reduce soil and water losses from slope land used for citrus production, information on the effects of management practices on soil fertility indices is either limited or nonexistent. This study was conducted to compare the effects of 10 years of various management practices, citrus intercropped with white clover (WC), citrus mulched with straw (SM), citrus intercropped with contour hedgerows (CH), citrus orchard land with impermeable membrane (IM), and citrus intercropped with wheat (Triticum aestivum) and peanut (Arachris hypogaea) (WP), as treatments on soil fertility indices with that of the conventional citrus management (CM). Results showed that the soil organic carbon, total and available nitrogen, available potassium, and water-stable aggregate (> 0.25 mm) contents at the 0–5 cm depth were higher for the WC and SM treatments than the CM treatment. There was also spatial variation in soil fertility along slopes of the WC and SM treatments. The soil total and available nitrogen, phosphorus, and potassium, and water-stable aggregate (> 0.25 mm) contents at both the 0–5 and 5–20 cm depths were higher for the CH and IM treatments than the CM treatment. The average soil available nitrogen and available potassium contents were higher for the WP treatment than the CM treatment, but the WP treatment had little effect on the soil organic carbon, total nitrogen, and water-stable aggregate (> 0.25 mm) contents. These suggested that white clover intercropping and straw mulching were the most effective approaches to improve soil fertility in citrus orchard land of the Three Gorges area.展开更多
Cyclocarya paliurus is only propagated from seeds which have pronounced dormancy. Overcoming seed dormancy is an important component of efficient and cost-effective seedling production of Cyclocarya paliurus. Changes ...Cyclocarya paliurus is only propagated from seeds which have pronounced dormancy. Overcoming seed dormancy is an important component of efficient and cost-effective seedling production of Cyclocarya paliurus. Changes in biochemical composition and enzyme activity were investigated during dormancy release. The activities of all the studied enzymes in the stratified seeds increased significantly, compared to those in the control samples. Of the enzymes examined, the activities of protease increased the most （413.8%）, followed by peroxidase （278.7%）, lipase （161.0%）, glucose-6-phosphate dehydrognase （149.1%） and amylase （60.6%） after 8 months of stratification. Crude fat and protein constituted the bulk of the storage reserves in mature seeds of C. pal# urus. Compared with the seeds before stratification, about 45% of the starch, 46% of the protein and 11% of the crude fat were depleted during dormancy release of C. paliurus seeds, while the soluble sugar content was enhanced by 101.5% in the germinating seeds. Correlation analysis showed, during dormancy release of C. paliurus seeds, a close positive relationship between POD and G6PDH activity as well as soluble sugar content and amylase activity, while there was a significant negative relationship between storage substances and their related enzyme activities.展开更多
Glycoprotein from Ginkgo biloba kernel may be allergic. In this paper, the allergic proteins were identified with Western blotting, and the 32 kDa glycoprotein was purified with ion exchange chromatography and gel chr...Glycoprotein from Ginkgo biloba kernel may be allergic. In this paper, the allergic proteins were identified with Western blotting, and the 32 kDa glycoprotein was purified with ion exchange chromatography and gel chromatography. With Western blotting, there were 3 allergic proteins with molecular weight 21, 32, and 36 kDa. With SDS-PAGE analysis and measurements of the protein and sugar contents, the isolation and purification technology of 32 kDa was confirmed. Ginkgo crude protein extract was precipitated with ammonium sulphate （saturation gradient： 40-80%）. The precipitate was purified by chromatography with DEAE-cellulose 52, then chromatography with Sephadex G-200 and the target glycoprotein was finally obtained. The analysis results showed the molecule of the glycoprotein was 32.12 kDa and the ratio of protein to sugar was 20.56：1. In conclusion, the purification method could be used in preparation of the glycoprotein, and the study could provide a basis for the further research of the glycoprotein.展开更多
Organic phosphorus （nonreactive E NRP） is a major component of P in sediments, but information about its chemical forms and dynamic transformation is limited. The chemical forms and dynamic behaviors of NRP in a sed...Organic phosphorus （nonreactive E NRP） is a major component of P in sediments, but information about its chemical forms and dynamic transformation is limited. The chemical forms and dynamic behaviors of NRP in a sediment profile from Lake Talhu, a freshwater and eutrophic lake in China, were investigated. Five forms of NRP in the sediments were extracted based on a chemical fractionation technique, including easily labile NRP （NaHCO3-NRP）, reactive metal oxide-bound NRP （HCl-NRP）, humic acid-associated NRP （NaOH-NRPnA）, fulvic acid-associated NRP （NaOH-NRPFA） and residual NRP （Res-TP）. There were notable transformations with increasing sediment depth from the labile NaHCOa-NRP and NaOH-NRP pools to the recalcitrant HCl-NRP and Res-TP pools, which caused the NRP to become increasingly recalcitrant as the early diagenetic processes proceeded. Further analyses showed that the relative changes in contents of organic matter and reactive Fe oxides in the sediment profile triggered a competition for binding NRP fractions and led to the transformation of NRP. The results highlighted the importance of abiotic processes in regulating the diagenesis of organic P and its stability in sediments.展开更多
Myeloblastosis(MYB) proteins constitute one of the largest transcription factor(TF) families in plants and play crucial roles in regulating plant physiological and biochemical processes, including adaptation to divers...Myeloblastosis(MYB) proteins constitute one of the largest transcription factor(TF) families in plants and play crucial roles in regulating plant physiological and biochemical processes, including adaptation to diverse abiotic stresses. These TF families contain highly conserved MYB repeats(1 R, R2 R3, 3 R and 4 R) at the N-terminus. Roles for MYB TFs have been reported in response to such stresses as dehydration, salt, cold, and drought. The characterization of Masson pine(Pinus massoniana) MYB TFs are reported, including the analysis of MYB TFs expression in seedlings under controlled conditions and two different phosphate(Pi) deficient treatments. By searching for conserved MYB motifs in full transcriptomic RNA sequencing data for P. massoniana, 59 sequences were identified as MYB TFs. Conserved domainstructures and comparative functional and phylogenetic relationships of these MYB TFs with those in Arabidopsis were assessed using various bioinformatics tools. Based on microarray analysis, P. massoniana MYB genes exhibited different expression patterns under the two Pi deficiency conditions. Genes encoding MYB TFs that showed increased expression under critical Pi deficiency were identified, and some MYBs were differentially expressed only under conditions of severe Pi starvation. These results are useful for the functional characterization of MYB TFs that may be involved in the response to Pi deficiency and play divergent roles in plants.展开更多
We acclimated adults of two viviparous （Phrynocephalus guinanens＆ and P. vlangalii） and one oviparous （P. versicolor） species of toad-headed lizards （Agamidae） to 28 ℃, 33 ℃ and 38 ℃ to examine whether therm...We acclimated adults of two viviparous （Phrynocephalus guinanens＆ and P. vlangalii） and one oviparous （P. versicolor） species of toad-headed lizards （Agamidae） to 28 ℃, 33 ℃ and 38 ℃ to examine whether thermal preference （preferred body temperature, Tp） and thermal tolerance （critical thermal minimum, CTMin; critical thermal maximum, CTMax） were affected by acclimation temperature, and correlate with body size and habitat use. Both Tp and CTMax were highest in P. versicolor and lowest in P. vlangalii, with P. guinanensis in between. The two viviparous species did not differ in CTMin and thermal tolerance range, and they both were more resistant to low temperatures and had a wider range of thermal tolerance than the oviparous species. Both CTMin and CTMax shifted upward as acclimation temperature increased in all the three species. Tp was higher in the lizards acclimated to 33 ℃ than in those to 28 ℃ or 38 ℃. The range of thermal tolerance was wider in the lizards acclimated to 28 ℃ than in those to 33 ℃ or 38 ℃. The data showed that： 1） thermal preference and tolerance were affected by acclimation temperature, and differed among the three species of Phrynocephalus lizards with different body sizes and habitat uses; 2） both Tp and CTMax were higher in the species exchanging heat more rapidly with the environment, and CTMin was higher in the species using warmer habitats during the active season; and 3） thermal preference and tolerance might correlat with body size and habitat use in Phrynocephalus lizards.展开更多
We incubated eggs of five Phrynocephalus species （P. albolineatus, P. axillaries, P. grumgrzimailoi, P. helioscopus and P. przewalskii） at three constant temperatures （24℃, 28℃ and 32℃） to examine differences i...We incubated eggs of five Phrynocephalus species （P. albolineatus, P. axillaries, P. grumgrzimailoi, P. helioscopus and P. przewalskii） at three constant temperatures （24℃, 28℃ and 32℃） to examine differences in incubation length and hatchling morphology among species and among temperature treatments. We combined data from this study with those reported previously for P. frontalis and P. versicolor to examine whether embryonic stage at laying is a causal factor for interspecific variation in incubation length, and whether the phylogenetic relationship inferred from hatchling morphology is consistent with the relationship based on mitochondrial DNA data. Mean values for incubation length differed among the five species studied herein and, in all these five species, incubation length decreased at a decreasing rate as temperature increased. In none of the five species did hatchling size （snout-vent length and body mass） and other morphological variables differ among the three temperature treatments. The seven oviparous Phrynocephalus lizards found in China differ from each other in hatchling morphology, and embryonic stage at laying is a causal factor of inter- and intra-specific variation in incubation length. The phylogenetic relationship inferred from hatchling morphology is not always consistent with the currently known relationship based on mitochondrial DNA data. Data from this study and those reported previously allow the conclusion that any Phrynocephalus species may have its unique position along the axis defined by hatchling morphology.展开更多
Geospatial patterns of forest fragmentation over the three traditional giant forested areas of China （Northeastern, southwestern and Southern China） were analyzed comparatively and reported based on a 250-m resoluti...Geospatial patterns of forest fragmentation over the three traditional giant forested areas of China （Northeastern, southwestern and Southern China） were analyzed comparatively and reported based on a 250-m resolution land cover dataset. Specifically, the spatial patterns of forest fragmentation were characterized by combining geospatial metrics and forest fragmentation models. The driving forces resulting in the differences of the forest spatial patterns were also investigated. Results suggested that forests in southwest China had the highest severity of forest fragmentation, followed by south region and northeast region. The driving forces of forest fragmentation in China were primarily the giant population and improper exploitation of forests. In conclusion, the generated information in the study provided valuable insights and implications as to the fragmentation patterns and the conservation of hiodiversity or genes, and the use of the chosen geospatial metrics and forest fragmentation models was quite useful for depicting forest fragmentation patterns.展开更多
The EC50 values of matrine and oxymatrine against five forest pathogenic fungi （Fusarium oxysporum, Valsa pini, Cladosporium oxysporum, Sphaeropsis sapinea, Marssonina brunnea） were examined by bioassay methods. The...The EC50 values of matrine and oxymatrine against five forest pathogenic fungi （Fusarium oxysporum, Valsa pini, Cladosporium oxysporum, Sphaeropsis sapinea, Marssonina brunnea） were examined by bioassay methods. The results demonstrated that matrine and oxymatrine had strong inhibitory activities to the conidium germination of the tested fungi. The ECso values of matrine for inhibiting the conidium germination of Marssonina brunnea, Cladosporium oxysporum, Sphaeropsis sapinea were 123μg·mL^-1, 272 μg·mL^-1, 1133 μg·mL^-1, respectively, and the EC50 values of oxymatrine for inhibiting the conidium germination of Fusarium oxysporum, Sphaeropsis sapinea were 532μg·mL^-1, 601μg·mL^-1, respectively. The hyphal growth of the fungi was also significantly inhibited by matrine and oxymatrine. The ECs0 values of matrine inhibiting the conidium germination of Sphaeropsis sapinea, Valsa pini, Fusarium oxysporum were 428μg·mL^-1, 535 μg·mL^-1, 592 μg·mL^-1, respectively. The EC50 values of oxymatrine inhibiting the conidium germination of Valsa pini, Fusarium oxysporum were 323, 618μg·mL^-1, respectively. In the synergetic tests the ECs0 values of the mixtures of thiophanate methyl （or chlorthalonil） and matrine （or oxymatrine） were lower than 34 μg·mL^-1 while their co-toxicity coefficients were significantly higher than 1130 It indicated that the mixture of the alkaloids and the chemical had potential practical utilization in controlling certain forest fungal diseases.展开更多
Seventeen morphological and anatomical characteristics of the leaves were selected from five natural populations to explore the variation in leaf traits of Lits ea core ana var.sinensis and the effects of geographical...Seventeen morphological and anatomical characteristics of the leaves were selected from five natural populations to explore the variation in leaf traits of Lits ea core ana var.sinensis and the effects of geographical environment on these variations.Nested analysis of variance,multiple comparisons,principal component analysis(PCA),and correlation analysis were conducted to explore the variations within and between populations and their correlation with geographical and climatic factors.Significant differences in the 17 leaf traits were observed within and among populations.On average,the relative contribution of within population variation to total variation was 24.8%,which was lower than among population variation(54.6%).The average differentiation coefficient of the traits was 65.8%,and the average coefficient of variation 11.8%,ranging from6.7%for main vein thickness to 21.4%for petiole length.The PC A results showed that morphological characteristics were divided into two categories,and the level of variation was greater than that of leaf anatomy.Most of the leaf traits were significantly correlated with geography and climate and showed a gradual variation with longitude,latitude,and altitude.In areas with high temperatures,less rainfall,and strong seasonal rainfall,the leaves are larger,longer and thicker.This study shows that variations in leaf traits of L.coreana var.sinensis mainly come from variations among populations.The level of trait differentiation among populations is high and the level of variation within populations low.These findings help further understand leaf morphological characteristics of this species and can provide a valuable reference for the protection and sustainable utilization of this natural resource.展开更多
Members of the WUSCHEL-related homeobox(WOX)transcription factor family are essential for determining cell fate and regulating diverse developmental processes in plants.Many WOX genes have been systematically investig...Members of the WUSCHEL-related homeobox(WOX)transcription factor family are essential for determining cell fate and regulating diverse developmental processes in plants.Many WOX genes have been systematically investigated in woody plants such as Populus trichocarpa,but not in Salix suchowensis.Whole-genome sequence data for S.suchowensis is now available for comprehensive study of WOX genes in S.suchowensis.We thus surveyed the genome of S.suchowensis and demonstrated active expression of 15 WOX genes.In a phylogenetic analysis of WOX genes,the 15 SsWOX genes clustered among the modern/WUS,intermediate and ancient clades similar to the WOX genes of Arabidopsis thaliana.Based on the conserved intron/exon structure,SsWOX genes in the same subgroup had similar conserved exon–intron structures and motif domains.Furthermore,among several SsWOX subgroups,WUS(Wuschel)-box and EAR(the ERF-associated amphiphilic repression)-like motifs were conserved.Expression profiles of WOX genes in roots,stems and leaves indicate that SsWOX genes have various conserved roles in the tissues.Comparative analysis of the expression patterns in Salix suchowensis with that of Arabidopsis suggests that different shoot regeneration abilities are controlled by different WOX genes in plants.The analysis provide an overview of differentially expressed SsWOX genes during shoot regeneration,but also contribute to understanding the evolution of WOX genes in Salicaceae and the interrelations of WOX genes and other transcription factors,providing targets for further study.展开更多
基金This study was supported by the National Natural Science Foundation of China(Grant No.31870613)Guizhou Province High-level Innovative Talents Training Plan Project(2016)5661.
文摘Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the understory.In this study,we selected three stands typical in south China(a Cryptomeria japonica plantation,a Quercus acutissima plantation,and a mixed stand of both)and three thinning intensities to determine the best understory light environ-ment for 3-year-old Phoebe bournei seedlings.The canopy structure,understory light environment,and photosynthe-sis and growth indicators were assessed following thin-ning.Thinning improved canopy structure and understory light availability of each stand;species composition was the reason for differences in the understory light environ-ment.Under the same thinning intensity,the mixed stand had the greatest light radiation and most balanced spectral composition.P.bournei photosynthesis and growth were closely related to the light environment;all three stands required heavy thinning to create an effective and sustained understory light environment.In a suitable understory light environment,the efficiency of light interception,absorption,and use by seedlings was enhanced,resulting in a higher carbon assimilation the main limiting factor was stomatal conductance.As a shade-avoidance signal,red/far-red radia-tion is a critical factor driving changes in photosynthesis and growth of P.bournei seedlings,and a reduction increased light absorption and use capacity and height:diameter ratios.The growth advantage transformed from diameter to height,enabling seedlings to access more light.Our findings suggest that the regeneration of shade-tolerant species such as P.bournei could be enhanced if a targeted approach to thinning based on stand type was adopted.
基金supported by the Natural Science Talent Funding of Guizhou University(202132,202318)the Innovative Talent Team Project of Seedling Breeding and plantation cultivation for Precious Tree Species in Guizhou(Qiankehe Platform Talents-CXTD[2023]006).
文摘As ubiquitous environmental contaminants,microplastics(MPs)have garnered global concern due to their persistence,bioaccumulation potential,and multifaceted threats to ecosystem health.These particles threaten terrestrial ecosystems via soil contamination;however,research on their phytotoxicity remains predominantly focused on herbaceous plants.The responses of woody plants to MPs and their interspecific differences are severely unexplored.Here,two important ecological and economical tree species in southern China,Pinus massoniana(P.massoniana)and Schima superba(S.superba),were selected to explore the ecotoxicity effects of polyethylene(PE)and polypropylene(PP)MPs(the two most abundant species in the soil)on seedling growth characteristics,specific leaf area(SLA)and biomass allocation at 0%,1%,5%and 10%concentration gradients in the 120-day potted experiment.The results showed that the inhibition effect of MPs was concentration and tree species-dependent.Seedling height,basal diameter,and total biomass of P.massoniana decreased significantly with increased concentration,while S.superba showed a non-significant growth effect at 1%concentration.The SLA was generally increased,revealing that plants enhanced their light capture ability through leaf morphological plasticity to compensate for the loss of carbon assimilation.There were interspecific differences in root investment strategies:the root-shoot ratio of P.massoniana was significantly reduced by 48.43%under 10%PP treatment.In comparison,the root-shoot ratio of S.superba was significantly reduced by maintaining a higher root-shoot ratio(65.26%higher than that of P.massoniana on average)and phased resource allocation(5%concentration biomass is higher than 10%)partially alleviated the toxic pressure.Collectively,our results indicate that the ecotoxicity of MPs was mainly driven by concentration and was not correlated with type(PE/PP),while the differences in tree species response were closely related to their resource allocation strategies and morphological plasticity.These findings imply that MPs contamination can differently impact the growth and development of dominant tree species,potentially altering the structure,diversity,and function of forest ecosystems.This study systematically revealed the growth response mechanism of native common tree species to MPs pollution and provided a theoretical basis for sustainable management of plantations and toxicological risk assessment of forest ecosystems.
基金supported by National Natue Science Foundation(39899370)
文摘Daxing'an Mountains and Xiaoxing'an Mountains are the two regions of the highest hattudes in China.The tem-pera ture increase is most obvious there in the last hundred yeas,compared with other ie gions of China.The forest vegetationecotone between Daxing'an Mounta ins and Xia oxing'an Mountains is bcate d be tween the latitude 48 and 53 N and longtude123 and 128 E.This ecotone is of great importa nce in study of gbbal clima te change due to its transitional fea ture of broa d-lea fconiferous mixe d forest and boreal forest.The bcation,geomorphology,climate,soi and ve ge tation types of the ecotoneare introduced in this paper.
文摘China was one of the earliest countries to set up a system to continuously inventory natural forest resources. From the beginning of the 1970s until today, seven forest resource inventories have been carried out. This research summarizes the progress of forest continuous inventories and analyzes the existing deficiencies ofChina’s forest continuous inventory system and forest management plan inventory. As stated above, this research offers corresponding countermeasures and suggestions: establishing a sample plot system for comprehensive national forest inventory and monitoring with each province’s continuous forest inventory based on the foundation of the national sample plot system, able to develop the province as a subset of the overall province-level forest resource inventory according to the actual conditions in each province. Through annual multi-resource/multi-benefit surveying of the forests, the monitoring of forest amounts, quality, functions and benefits will be assisted in its entirety. The further integration of the forest continuous inventory and the forest management plan inventory is also discussed. This research also proposes the varied probability sampling method with sub-compartments as the basic sampling unit (or combinations of sub-compartments). This will also satisfy the requirements of ecological inventory by region.
基金Supported by the Program for Science and Technology Development of Jiangsu Province,China (No. BE2008393)the InnovationPlan for Graduate Students of Jiangsu Province,China (No. CX08B 028Z)the Public Welfare Scientific Special of State ForestryAdministration in China (No. 201004061)
文摘A few soil microorganisms can convert insoluble forms of phosphorus （P） to an accessible form to increase plant yields The objectives of this study were to isolate, screen and identify the phosphobacteria, i.e., phosphate-solubilizing bacteria （PSB） and phosphate-mineralizing bacteria （PMB）, in some poplar plantations and to select potential microbial inoculants that could increase the P uptake by plants. Seventy four PSB strains and 138 PMB strains were preliminarily screened from 797＂colonies isolated from the rhizosphere soil of poplar by the visible decolorization in the National Botanical Research Institute＇s phosphate growth medium （NBRIP） containing a pH indicator of bromophenol and by the clear/halo zone on yeast malt agar plate, respectively. Then, based on the solubilization of Ca3（PO4）2 in liquid NBRIP medium and the mineralization of lecithin in liquid Menkina medium, 15 PS1R strains and 7 PMB strains were further determined for their abilities to solubilize Ca3（PO4）2 and to mineralize lecithin. The results showed that the 15 PSB strains exhibited inorganic P-solubilizing abilities ranging between 376.62 and 669.56 mg L-1 and the 7 PMB strains exhibited organic P-mineralizing abilities vaxying from 0.32 to 1.56 mg L-1 three days after incubation. Three of PSB strains with the highest P-solubilizing ability, named JW-JS1, JW-JS2 and JW-SX2, were all preliminarily identified as Pseudomonas ftuorescens, while two of PMB strains with the highest P-mineralizing ability, named JYZ-SD1 and JYT-JS2, were preliminarily identified as Bacillus cereus and Bacillus subtilis, respectively. All the efficient PSB and PMB strains should be further studied under both pot culture and field conditions to test their beneficial effects on poplar.
基金Foundation project： This paper is supported by the National Natural Science Foundation of China （the grant number No.39970608）.
文摘Effects of NaCI on seed germination, leaf gas exchange and seedling growth were investigated. The germination of P. tatarinowii seeds was delayed in the presence of NaCl, and was significantly inhibited when NaCl concentration exceeded 17 mM （1.0 g·L^-1）. NaCl treatments induced reductions of transpiration rate, stomatal conductance and net photosynthetic rate and their reductions were significant with the increasing of NaCl concentration. However, intercellular CO2 concentration in seedling leaves under salt stress was significantly higher than that of controls. There was a significant reduction in survival, basal diameter increment and height increment witl increasing NaCl concentration 50 days after NaCl treatment, and a significant reduction in the dry weight increment of roots, stems, and leaves was also observed in the NaCl treatments. The deleterious effect on the biomass increment was more evident in the case of stems and leaves. Results from this study suggest that P. tatarinowii is sensitive to salinity stress and the salinity threshold for seedling growth might be less 34 mM （2.0 g· L^-1）.
基金Project supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (No. ISSASIP0205)the National Key Basic Research Support Foundation of China (No. 1999011805)+3 种基金the State Key Laboratory of Soil and Sustainable Agriculture, Chinathe Scientific Research Foundation for Returned Overseas Chinese Scholarsthe State Education Ministry of Chinaand the National Natural Science foundation of China (No. 40305019)
文摘A one-year study in a typical red soil region of southern China was conducted to determine atmospheric nitrogen (N) fluxes of typical N compounds (NH3, NH4-N, NO3-N, and NO2) and contribution of three sources (gas, rainwater, and particles) to N deposition. From July 2003 to June 2004, the total atmospheric N deposition was 70.7 kg N ha-1, with dry deposition accounting for 75% of the total deposition. Dry NH3 deposition accounted for 73% of the dry deposition and 55% of the total deposition. Moreover, NO2 contributed 11% of the dry deposition and 8% of the total deposition. Reduced N compounds (NH4+ and NH3) were the predominate contributors, accounting for 66% of the total deposition. Therefore, atmospheric N deposition should be considered when soil acidification and critical loads of atmospheric deposition on soils are estimated.
基金Foundation item： Project supported by Priority Academic Program Development of Jiangsu Higher Education Institutions （PAPD） and National Basic Research Program of China （2006CB403301）
文摘To investigate the effects of exogenous lanthanum （La） on Alternanthera philoxeroides （Mart.） Griseb under perchlorate stress, changes in the growth and physiological parameters were investigated in solution culture experiments under controlled condi- tions. Different concentrations of La （NO3）3 were used in our study. It was shown that 0. 1 and 0.5 mg/L La3＋ alleviated the inhibition effect of perchlorate on A. philoxeroides, including relative growth yield, dry weight of different organs, leaf area and root activity. And La3＋ prevented decline in the relative chlorophyll content and chlorophyll fluorescence parameters including Fv/Fm, Fv＇/Frn＇, φPSll and ETR induced by perchlorate stress. Moreover, 0.5 mg/L La3＋ showed an optimal mitigative effect, while excess La3＋ （5.0 mg/L） led to synergistic effect on stress. Correlation analysis revealed a significant positive relationship between growth indexes and the chlorophyll fluorescence parameters, root activity and relative chlorophyll content （p〈0.05）. The results suggested that appropriate concentration of La3＋ could effectively alleviate growth inhibition and injury ofA. philoxeroides caused by perchlorate stress, and the mitigative effect of La3＋ might be achieved by improving root activity, maintaining chlorophyll content and promoting photochemical efficiency of photosystem II ofA. philoxeroides under perchlorate stress.
基金Supported by the Chinese National Public Benefit Program for Forestry (No. 200804040)the Program of Introducing International Advanced Forestry Technique of the State Forestry Administration of China (948 Program) (No. 2005-4-17)the National Natural Science Foundation of China (Nos. 30870410, 40871147, and 30271069)
文摘In the Three Gorges Area of China, soil erosion and the resultant non-point source pollution and ecological degradation have endangered agricultural ecosystems and fresh water reservoirs. Although efforts have been undertaken to reduce soil and water losses from slope land used for citrus production, information on the effects of management practices on soil fertility indices is either limited or nonexistent. This study was conducted to compare the effects of 10 years of various management practices, citrus intercropped with white clover (WC), citrus mulched with straw (SM), citrus intercropped with contour hedgerows (CH), citrus orchard land with impermeable membrane (IM), and citrus intercropped with wheat (Triticum aestivum) and peanut (Arachris hypogaea) (WP), as treatments on soil fertility indices with that of the conventional citrus management (CM). Results showed that the soil organic carbon, total and available nitrogen, available potassium, and water-stable aggregate (> 0.25 mm) contents at the 0–5 cm depth were higher for the WC and SM treatments than the CM treatment. There was also spatial variation in soil fertility along slopes of the WC and SM treatments. The soil total and available nitrogen, phosphorus, and potassium, and water-stable aggregate (> 0.25 mm) contents at both the 0–5 and 5–20 cm depths were higher for the CH and IM treatments than the CM treatment. The average soil available nitrogen and available potassium contents were higher for the WP treatment than the CM treatment, but the WP treatment had little effect on the soil organic carbon, total nitrogen, and water-stable aggregate (> 0.25 mm) contents. These suggested that white clover intercropping and straw mulching were the most effective approaches to improve soil fertility in citrus orchard land of the Three Gorges area.
基金This work is supported by the National Natural Science Foundation of China （Grant No. 30371156）in part by Grant sx （2003） 083 from the ＂Three Agriculture Engineering Program of Jiangsu Province＂.
文摘Cyclocarya paliurus is only propagated from seeds which have pronounced dormancy. Overcoming seed dormancy is an important component of efficient and cost-effective seedling production of Cyclocarya paliurus. Changes in biochemical composition and enzyme activity were investigated during dormancy release. The activities of all the studied enzymes in the stratified seeds increased significantly, compared to those in the control samples. Of the enzymes examined, the activities of protease increased the most （413.8%）, followed by peroxidase （278.7%）, lipase （161.0%）, glucose-6-phosphate dehydrognase （149.1%） and amylase （60.6%） after 8 months of stratification. Crude fat and protein constituted the bulk of the storage reserves in mature seeds of C. pal# urus. Compared with the seeds before stratification, about 45% of the starch, 46% of the protein and 11% of the crude fat were depleted during dormancy release of C. paliurus seeds, while the soluble sugar content was enhanced by 101.5% in the germinating seeds. Correlation analysis showed, during dormancy release of C. paliurus seeds, a close positive relationship between POD and G6PDH activity as well as soluble sugar content and amylase activity, while there was a significant negative relationship between storage substances and their related enzyme activities.
基金supported by Research Fund for the Doctoral Program of Higher Education of China(200802980004 and 20070298008)the National Natural Science Fundation of China (30872055)
文摘Glycoprotein from Ginkgo biloba kernel may be allergic. In this paper, the allergic proteins were identified with Western blotting, and the 32 kDa glycoprotein was purified with ion exchange chromatography and gel chromatography. With Western blotting, there were 3 allergic proteins with molecular weight 21, 32, and 36 kDa. With SDS-PAGE analysis and measurements of the protein and sugar contents, the isolation and purification technology of 32 kDa was confirmed. Ginkgo crude protein extract was precipitated with ammonium sulphate （saturation gradient： 40-80%）. The precipitate was purified by chromatography with DEAE-cellulose 52, then chromatography with Sephadex G-200 and the target glycoprotein was finally obtained. The analysis results showed the molecule of the glycoprotein was 32.12 kDa and the ratio of protein to sugar was 20.56：1. In conclusion, the purification method could be used in preparation of the glycoprotein, and the study could provide a basis for the further research of the glycoprotein.
基金supported by the National Natural Scientific Foundation of China (No. 40871220,40730528)the Natural Scientific Foundation of Jiangsu Province,China (No. BK2010606)the Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences(No. NIGLAS2010KXJ01)
文摘Organic phosphorus （nonreactive E NRP） is a major component of P in sediments, but information about its chemical forms and dynamic transformation is limited. The chemical forms and dynamic behaviors of NRP in a sediment profile from Lake Talhu, a freshwater and eutrophic lake in China, were investigated. Five forms of NRP in the sediments were extracted based on a chemical fractionation technique, including easily labile NRP （NaHCO3-NRP）, reactive metal oxide-bound NRP （HCl-NRP）, humic acid-associated NRP （NaOH-NRPnA）, fulvic acid-associated NRP （NaOH-NRPFA） and residual NRP （Res-TP）. There were notable transformations with increasing sediment depth from the labile NaHCOa-NRP and NaOH-NRP pools to the recalcitrant HCl-NRP and Res-TP pools, which caused the NRP to become increasingly recalcitrant as the early diagenetic processes proceeded. Further analyses showed that the relative changes in contents of organic matter and reactive Fe oxides in the sediment profile triggered a competition for binding NRP fractions and led to the transformation of NRP. The results highlighted the importance of abiotic processes in regulating the diagenesis of organic P and its stability in sediments.
基金funded by the Natural Science Foundation of Guizhou Province,P.R.China(20161051)the National Natural Science Foundation of China(31660185)the Doctoral Fund Project of Guizhou University,P.R.China(201464)。
文摘Myeloblastosis(MYB) proteins constitute one of the largest transcription factor(TF) families in plants and play crucial roles in regulating plant physiological and biochemical processes, including adaptation to diverse abiotic stresses. These TF families contain highly conserved MYB repeats(1 R, R2 R3, 3 R and 4 R) at the N-terminus. Roles for MYB TFs have been reported in response to such stresses as dehydration, salt, cold, and drought. The characterization of Masson pine(Pinus massoniana) MYB TFs are reported, including the analysis of MYB TFs expression in seedlings under controlled conditions and two different phosphate(Pi) deficient treatments. By searching for conserved MYB motifs in full transcriptomic RNA sequencing data for P. massoniana, 59 sequences were identified as MYB TFs. Conserved domainstructures and comparative functional and phylogenetic relationships of these MYB TFs with those in Arabidopsis were assessed using various bioinformatics tools. Based on microarray analysis, P. massoniana MYB genes exhibited different expression patterns under the two Pi deficiency conditions. Genes encoding MYB TFs that showed increased expression under critical Pi deficiency were identified, and some MYBs were differentially expressed only under conditions of severe Pi starvation. These results are useful for the functional characterization of MYB TFs that may be involved in the response to Pi deficiency and play divergent roles in plants.
基金supported by the grants from the National Natural Science Foundation of China(31071910 and 31200282)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘We acclimated adults of two viviparous （Phrynocephalus guinanens＆ and P. vlangalii） and one oviparous （P. versicolor） species of toad-headed lizards （Agamidae） to 28 ℃, 33 ℃ and 38 ℃ to examine whether thermal preference （preferred body temperature, Tp） and thermal tolerance （critical thermal minimum, CTMin; critical thermal maximum, CTMax） were affected by acclimation temperature, and correlate with body size and habitat use. Both Tp and CTMax were highest in P. versicolor and lowest in P. vlangalii, with P. guinanensis in between. The two viviparous species did not differ in CTMin and thermal tolerance range, and they both were more resistant to low temperatures and had a wider range of thermal tolerance than the oviparous species. Both CTMin and CTMax shifted upward as acclimation temperature increased in all the three species. Tp was higher in the lizards acclimated to 33 ℃ than in those to 28 ℃ or 38 ℃. The range of thermal tolerance was wider in the lizards acclimated to 28 ℃ than in those to 33 ℃ or 38 ℃. The data showed that： 1） thermal preference and tolerance were affected by acclimation temperature, and differed among the three species of Phrynocephalus lizards with different body sizes and habitat uses; 2） both Tp and CTMax were higher in the species exchanging heat more rapidly with the environment, and CTMin was higher in the species using warmer habitats during the active season; and 3） thermal preference and tolerance might correlat with body size and habitat use in Phrynocephalus lizards.
基金supported by grants from the National Natural Science Foundation of China (31071910 and 31200282)Priority Academic Program Development of Jiangsu Higher Education Institutions and High Academic Talent Foundation of Nanjing Forestry University (GXL201306)
文摘We incubated eggs of five Phrynocephalus species （P. albolineatus, P. axillaries, P. grumgrzimailoi, P. helioscopus and P. przewalskii） at three constant temperatures （24℃, 28℃ and 32℃） to examine differences in incubation length and hatchling morphology among species and among temperature treatments. We combined data from this study with those reported previously for P. frontalis and P. versicolor to examine whether embryonic stage at laying is a causal factor for interspecific variation in incubation length, and whether the phylogenetic relationship inferred from hatchling morphology is consistent with the relationship based on mitochondrial DNA data. Mean values for incubation length differed among the five species studied herein and, in all these five species, incubation length decreased at a decreasing rate as temperature increased. In none of the five species did hatchling size （snout-vent length and body mass） and other morphological variables differ among the three temperature treatments. The seven oviparous Phrynocephalus lizards found in China differ from each other in hatchling morphology, and embryonic stage at laying is a causal factor of inter- and intra-specific variation in incubation length. The phylogenetic relationship inferred from hatchling morphology is not always consistent with the currently known relationship based on mitochondrial DNA data. Data from this study and those reported previously allow the conclusion that any Phrynocephalus species may have its unique position along the axis defined by hatchling morphology.
基金This research was performed while the lead author held a National Research Council (NRC) Research Associateship Program Award a postdoctoral program sponsored by the NRC in partnership with the U.S. Geological Survey
文摘Geospatial patterns of forest fragmentation over the three traditional giant forested areas of China （Northeastern, southwestern and Southern China） were analyzed comparatively and reported based on a 250-m resolution land cover dataset. Specifically, the spatial patterns of forest fragmentation were characterized by combining geospatial metrics and forest fragmentation models. The driving forces resulting in the differences of the forest spatial patterns were also investigated. Results suggested that forests in southwest China had the highest severity of forest fragmentation, followed by south region and northeast region. The driving forces of forest fragmentation in China were primarily the giant population and improper exploitation of forests. In conclusion, the generated information in the study provided valuable insights and implications as to the fragmentation patterns and the conservation of hiodiversity or genes, and the use of the chosen geospatial metrics and forest fragmentation models was quite useful for depicting forest fragmentation patterns.
基金This work was supported by a project of NationalNatural Science Foundation of China (No. 30170776)
文摘The EC50 values of matrine and oxymatrine against five forest pathogenic fungi （Fusarium oxysporum, Valsa pini, Cladosporium oxysporum, Sphaeropsis sapinea, Marssonina brunnea） were examined by bioassay methods. The results demonstrated that matrine and oxymatrine had strong inhibitory activities to the conidium germination of the tested fungi. The ECso values of matrine for inhibiting the conidium germination of Marssonina brunnea, Cladosporium oxysporum, Sphaeropsis sapinea were 123μg·mL^-1, 272 μg·mL^-1, 1133 μg·mL^-1, respectively, and the EC50 values of oxymatrine for inhibiting the conidium germination of Fusarium oxysporum, Sphaeropsis sapinea were 532μg·mL^-1, 601μg·mL^-1, respectively. The hyphal growth of the fungi was also significantly inhibited by matrine and oxymatrine. The ECs0 values of matrine inhibiting the conidium germination of Sphaeropsis sapinea, Valsa pini, Fusarium oxysporum were 428μg·mL^-1, 535 μg·mL^-1, 592 μg·mL^-1, respectively. The EC50 values of oxymatrine inhibiting the conidium germination of Valsa pini, Fusarium oxysporum were 323, 618μg·mL^-1, respectively. In the synergetic tests the ECs0 values of the mixtures of thiophanate methyl （or chlorthalonil） and matrine （or oxymatrine） were lower than 34 μg·mL^-1 while their co-toxicity coefficients were significantly higher than 1130 It indicated that the mixture of the alkaloids and the chemical had potential practical utilization in controlling certain forest fungal diseases.
基金the National Natural Science Foundation of China(32060349)China Scholarship Council([2021]15)。
文摘Seventeen morphological and anatomical characteristics of the leaves were selected from five natural populations to explore the variation in leaf traits of Lits ea core ana var.sinensis and the effects of geographical environment on these variations.Nested analysis of variance,multiple comparisons,principal component analysis(PCA),and correlation analysis were conducted to explore the variations within and between populations and their correlation with geographical and climatic factors.Significant differences in the 17 leaf traits were observed within and among populations.On average,the relative contribution of within population variation to total variation was 24.8%,which was lower than among population variation(54.6%).The average differentiation coefficient of the traits was 65.8%,and the average coefficient of variation 11.8%,ranging from6.7%for main vein thickness to 21.4%for petiole length.The PC A results showed that morphological characteristics were divided into two categories,and the level of variation was greater than that of leaf anatomy.Most of the leaf traits were significantly correlated with geography and climate and showed a gradual variation with longitude,latitude,and altitude.In areas with high temperatures,less rainfall,and strong seasonal rainfall,the leaves are larger,longer and thicker.This study shows that variations in leaf traits of L.coreana var.sinensis mainly come from variations among populations.The level of trait differentiation among populations is high and the level of variation within populations low.These findings help further understand leaf morphological characteristics of this species and can provide a valuable reference for the protection and sustainable utilization of this natural resource.
基金supported by the National Key Research and Development Plan of China(2016YFD0600101)the Fundamental Research Funds for the Central Non-Profit Research Institution of CAF(CAFYBB2014QB015)+3 种基金the National Natural Science Foundation of China(31570662,31500533,and 61401214)Jiangsu Provincial Department of Housing and Urban–Rural Development(2016ZD44)2017 Graduate Research and Innovation Program Projects in Jiangsu Province(KYCY17_0827)the PAPD(Priority Academic Program Development)program at Nanjing Forestry University
文摘Members of the WUSCHEL-related homeobox(WOX)transcription factor family are essential for determining cell fate and regulating diverse developmental processes in plants.Many WOX genes have been systematically investigated in woody plants such as Populus trichocarpa,but not in Salix suchowensis.Whole-genome sequence data for S.suchowensis is now available for comprehensive study of WOX genes in S.suchowensis.We thus surveyed the genome of S.suchowensis and demonstrated active expression of 15 WOX genes.In a phylogenetic analysis of WOX genes,the 15 SsWOX genes clustered among the modern/WUS,intermediate and ancient clades similar to the WOX genes of Arabidopsis thaliana.Based on the conserved intron/exon structure,SsWOX genes in the same subgroup had similar conserved exon–intron structures and motif domains.Furthermore,among several SsWOX subgroups,WUS(Wuschel)-box and EAR(the ERF-associated amphiphilic repression)-like motifs were conserved.Expression profiles of WOX genes in roots,stems and leaves indicate that SsWOX genes have various conserved roles in the tissues.Comparative analysis of the expression patterns in Salix suchowensis with that of Arabidopsis suggests that different shoot regeneration abilities are controlled by different WOX genes in plants.The analysis provide an overview of differentially expressed SsWOX genes during shoot regeneration,but also contribute to understanding the evolution of WOX genes in Salicaceae and the interrelations of WOX genes and other transcription factors,providing targets for further study.
