Abstract:The cDNA and DNA sequences of β-1,3-glucanase genes (Mugsp1.2-Mugsp5) were cloned from the leaves of the wild banana（Musa spp.） in Sanming City using RT-PCR and RACE methods.Sequences and bioinformatics analysis showed that the ORF sequences of Mugsp1.2,Mugsp2,Mugsp3,Mugsp4 and Mugsp5 were 1 020,1 047,999,1 023 and 960 bp,respectively,which encoded 339,348,332,340 and 319 amino acids,respectively.Mugsp1.2,Mugsp2 and Mugsp4 contained both N-terminal and C-terminal(CTPP) signal peptide,suggesting they belong to Ⅰclass of β-1,3-glucanase,while Mugsp3 contained N-terminal without CTPP signal peptide,and Mugsp5 contained neither N-terminal nor CTPP signal peptide.We constructed the expression vectors of Mugsp1.2,Mugsp2,Mugsp4 and expressed the genes in onion epidermal cells.The results of subcellular localization showed that Mugsp1.2,Mugsp2,Mugsp4 were expressed on plasma membranes and cytoplasm at room temperature,respectively,while all Mugsp1.2,Mugsp2 and Mugsp4 could transfer to cell nucleus under 8 ℃.The expressions of β-1,3-glucanase genes under diffierent tempertaures were dectected by qRT-PCR.The results revealed that all β-1,3-glucanase genes responded to cold stress,but their expression levels were differed from each other.SA treatment under low temperature would delayed the expression of β-1,3-glucanase genes.

Abstract:Using RT-PCR technology,we cloned the R2R3 MYB gene LbMYB103 cDNA fragment,which contains a complete open reading frame(ORF),from wolfberry variety ‘Ningqi No.1’.The base sequence was entirely consistent with that of the known gene HQ415755.The plant over expression vector pMDC83-LbMYB103-GFP was constructed with Gateway Technology and confirmed by enzyme digestion and sequencing.We transformed pMDC83-LbMYB103 into onion epidermal cells using particle bombardment and found that LbMYB103 was located in the nucleus.We used the real-time quantitative PCR approach to analyze the expression pattern of LbMYB103 in various organs,and the result showed that expression of LbMYB103 was the highest in flower and anther,relatively lower in fruits,but undetectable in leaf,stem and root,indicating that LbMYB103 may play some roles in wolfberry reproductive organ process,such as anther development.We transformed pMDC83-LbMYB103 into Arabidopsis thaliana（Col-0）using Agrobacterium-mediated method.After plant selection and regeneration,a total of 52 and 29 regenerated T₁ and T₂ plants with resistance were obtained respectively.The PCR detection showed that a total of 41 T₁ plants and 23 T₂ plants containing LbMYB103 gene,and the real-time PCR analysis proved that LbMYB103 gene in transgenic A.thaliana could conduct normal expression.The phenotypic observation showed abnormal anther and flower development,shorten pods without seed both in T₁ and T₂ transgenic A.thaliana,further indicating LbMYB103 gene might be related to the plant fertility.The results lay a foundation for further study on the LbMYB103 gene,which may play a regulating role in the process of wolfberry anther development.

Abstract:In this study,we cloned cDNA and DNA sequences of anthocyanin synthase (ANS) gene,named MaANS,based on transcriptome sequencing in Muscari armeniacum.We did real-time fluorescence quantitative analysis about MaANS.While taking advantage of chromosome walking.We cloned a 1 044 bp upstream sequence of MaANS.Bioinformatic analysis showed that MaANS contains a 1 065 bp open reading frame,encoding 355 amino acids.The consistency of cloned DNA and cDNA is 89.62%,DNA sequence inserts a 79 bp intron from 515 bp to 594 bp on downstream of ATG.TATA-box is at -70 bp of the promoter which has a plurality of light-responsive elements and MYB binding sites.Real-time fluorescence quantitative analysis showed MaANS was predominant expression in flower and the expression level at fully colored stage was the highest.In this study,gene cloning and expression analysis on MaANS are important to in-depth study the function of MaANS gene and analyze the colored mechanism of Muscari armeniacum.

Abstract:The experiment cloned an E3 ubiquitin ligase gene LeRma1(GenBank accession No XM_004243764.1)by RT-PCR method with tomato ‘Hadafen 801’ used as experimental materials.To provide a theoretical basis for the cultivation and improved varieties of tomato,we analyzed the gene sequence,while studied the expression and physiological characteristics of LeRma1 gene in different parts of the tomato plants under abiotic stress(drought,salt,alkali,high temperature,low temperature).The results showed that:(1)LeRma1 gene sequence analysis showed that the length of LeRma1 gene was 729 bp,which encoded 242 amino acids.It was predicted that the molecular mass of its protein was 27.05 kD,and pI was 7.97.Homology analysis showed that the deduced amino acid sequence exhibited high homology with Solanum tuberosum（91% similarity）.(2)RT-PCR results indicating that the gene were expressed in roots,stems,leaves,flowers and fruits of tomato,and the changes in expression levels were not significantly different.(3)Expression of LeRma1 had the advantage in leaves,and the changes in expression levels were not significantly different in roots under the whole drought stress.The other drought-related genes DREB2A,LEA,ABI3 are all expression in leaves,and they were enhanced expression compared with the control,while DREB2A,ABI3 have not detected in roots under the whole drought stress.(4)Major membrane lipid peroxidation product of MDA content was increased significantly,and plasma membrane systems were severely damaged,the protective enzyme activity increased significantly,and activity in roots was significantly higher than that in leaves.(5)LeRma1 gene was enhanced expression in roots and leaves of tomato,and the gene in the leaves all starting enhanced expression after stress 3 h under abiotic stress(salt,alkali,high temperature,low temperature).The results showed that LeRma1 was the gene of enhancement expression by drought-induced and it had the advantage in leaves.It showed that there were some differences that the function of the LeRma1 genes in different tissues（organizational differences）under drought stress,and LeRma1 genes may be participate response of drought stress tolerance and the signal transduction process,it also might play an important role in the tomato under the other abiotic stresses.

Abstract:Based on banana EST library，we cloned a cDNA of TLP protein from Musa acuminata subsp.malaccensis.This cDNA has an open reading frame of 942 nucleotides,which encodes a protein of 313 amino acids.Blast found that its sequence has a high identity with other thaumatin-like proteins(TLPs) and a specific conserved domain TLPs share was found by using Conserved Domain Search Service (CD Search)tool in NCBI and then we named it MaTLP1.Phylogenetic tree indicated that this protein has a close genetic relationship with Phoenix dactylifera.Moreover,it has similar evolutional pattern with M.acuminata subsp.malaccensis.Organ specific expression analysis showed that expression of MaTLP1 was high in roots,corms,cauloids and weak in leafs,flowers and fruits.Real-time PCR analysis showed that expression of MaTLP1 was highly increased in resistant banana cultivars against pathogen Fusarium oxysporum f.sp.cubense(Foc) and was fluctuated not obviously in susceptible banana cultivars related to resistant cultivars.These results revealed that MaTLP1 plays an important role in banana M.acuminate resistance against pathogen Fusarium oxysporum f.sp.cubense.

Abstract:The full length cDNA of a sHSP17.3 was identified by analysis of the transcriptome of Juglans regia,which was named as JrsHSP17.3.The ORF of JrsHSP17.3 is 474 bp in length and encodes a 17.64 kDa protein with 157 amino acid residues and the theoretical pI of 5.35.To understand the tissue specific and temperature responsive expression profiles,we analyzed the transcription levels of JrsHSP17.3 in roots,stems and leaves exposed to heat and cold stresses at different time points by quantitative real time PCR (qRT-PCR).The results showed that JrsHSP17.3 was expressed more or less in stems,roots and leaves,and was obviously induced after high (36 ℃-52 ℃) and low (16 ℃-6 ℃) temperature treatments,among which the highest expression level was 142.02-fold of control under 12℃ for 1 h,suggesting JrsHSP17.3 could response to heat and cold temperature stresses.These results will provide a basis for further understanding the function of JrsHSP17.3 in cold and heat tolerance.

Abstract:The object of this study was to identify and characterize the haplotypes of Vp-1A in Tritivum urartu by PCR and semi-quantitative RT-PCR and their phylogenetic relationship with other wheat related species.In total,4 novel Vp-1A haplotypes were explored among a collection of 20 T.urartu genotypes and designated as TuVp-1Abgi,TuVp-1Acgh,TuVp-1Adfi and TuVp-1Aefi,respectively.The main differences between TaVp-1Aa (AJ400712 ) in common wheat and the newly identified haplotypes were the numbers of TTC repeat,the deletions and SNPs in second and fifth introns.In addition,the expression levels of Vp-1A homologues were different in genotypes harboring these 4 haplotypes.Furthermore,different mRNA levels among the four genotypes were observed after ABA treatment,indicating their different responsiveness to ABA exposure.These results suggested that the indels in the second,third and fifth intron regions of the Vp-1A gene affected its expression and its sensitivity to ABA,and thus seed dormancy.Therefore,our study characterized the Vp-1A haplotypes in a set of T.urartu germplasm and identified a novel haplotype TuVp-1Adfi which might be useful in wheat improvement for PHS resistance.

Abstract:To elaborate the biological function of PEPC which encodes phosphoenolpyruvate carboxylase from C₄ halophyte Suaeda aralocaspica,we investigated the performance of recombinant PEPC in Escherichia coli Transetta (DE3) under various abiotic stresses.The full-length cDNA of PEPC (GenBank accession No.KP985714) was obtained by 5′-RACE technique and its procaryotic expression vector pGEX-4T-1-PEPC was constructed.The content and enzyme activity of PEPC were measured by the spectrophotometric method and enzyme linked immunosorbent assay (ELISA).Meantime,the tolerance of the recombinant E.coli Transetta::pGEX-4T-1-PEPC to different abiotic stresses was also investigated.Bioinformatics analyses showed that PEPC contained 2 901 bp nucleotides and encoded 966 amino acids,which possesses the typical conserved domains of PEPC (e.g.active sites VlTAHPTQsiRR and VMIGYSDSgKDAG),and shares 90% amino acid similarity to PEPC from Beta vulgaris;our PEPC was a non-secretory PEPC-1 type hydrophilic protein without signal peptide sequence,and the molecular weight of the recombinant PEPC was approximately 130-140 kD,which was confirmed by western blot analysis.The recombinant PEPC presented relatively higher enzymatic activity when induced by 0.8 mmol/L IPTG at 37 ℃.Compared with the control strain,the recombinant E.coli Transetta::pGEX-4T-1-PEPC showed better growth performance under various abiotic stresses ［i.e.200-800 mmol/L NaCl,5%-20% PEG 6 000,25 ℃-52 ℃,50-400 μmol/L methyl viologen,and the wide acid and base range (pH 3.0-11.0)］.The results showed that overexpression of PEPC gene from S.aralocaspica in E.coli enhanced the tolerance under various abiotic stresses,which suggests that PEPC may confer stress tolerance to E.coli.Our work can provide more evidence for revealing the biological function of PEPC from S.aralocaspica.

Abstract:In this study,different disease-resistant inbred lines of maize,Mo17 (high),Zheng58 (medium),Ji419 (low),were inoculated with the pathogen spore of southern leaf blight,C.heterostrophus,for 0,6,12,24,36 and 48 hours.Through semi-quantitative and real-time PCR technology,the expression patterns of some key genes were explored in response to pathogen infection,including TPS6 and TPS11 for sesquiterpenoid phytoalexin Zealexin biosynthesis,An2 for diterpenoid phytoalexin Kauralexin biosynthesis,and AOC,the key gene of jasmonic acid (JA) metabolism.The results were followed:TPS6 and TPS11 gene expression in Mo17 were not induced significantly while the gene accumulation of An2 increased rapidly after inoculation.In the mean time,AOC gene expression was significantly increased after inoculation for 12 h in Mo17.TPS6 and TPS11 gene expression in Zheng58 increased rapidly,and reached the highest at 24 h.The An2 gene expression gradually increased,but the difference was not significant.The AOC gene expression increased significantly after inoculation for 6 h.The TPS6,TPS11 and An2 of Ji419 were upregulated in 24 h,slower than that in other two lines,and AOC gene expression showed a decreasing trend in the early phase and reached the highest levels at 24 h and 48 h.These results indicated that two types of terpenoid phytoalexins exhibited different metabolic response temporally in response to C.heterostrophus inoculation,but both were mediated with JA signal.The defense response mediated by metabolism of terpenoid phytoalexin was faster in resistant inbred line than that in the susceptible one,which is consistent with their resistance difference.Investigation of the defense response for terpenes phytoalexin metabolic genes provided an important theoretical basis for clarifying the defense mechanisms of maize varieties with different resistance against southern leaf blight.

Abstract:Leaves epidermis of maize (Zea mays L.) grown in field conditions were torn,fixed,stained via combining the simple staining,counterstaining,fluorescence and other cytological chromogenic methods,and the generation time,developmental process,distribution,morphological characteristics of short cells in epidermis of maize were observed and the relationship of K⁺ and H₂O₂ distribution change of the cork cells with those in other epidermal cells and the stomatal switch were investigated through optical microscopy,fluorescence microscopy,and scanning electron microscopy.The study can provide a cell theoretical basis for further exploration in new functions of short cells.The results showed that:(1) short cells appeared when new epidermal tissue in the multi-leaf positions of maize formed,and the generation occurred in all plants from the seventh new leaf,the base of the sixth leaf of most plants and the fifth leaf of few plants,and appeared in all later grown leaves.Short cells density of different parts of leaf increased with leaf position elevating.No short cells were found in the four initial leaves of all plants (because of no further growth).(2) The initial leaf epidermal cells divided asymmetrically to produce alternating long and short cells.Some short epidermal cells divided horizontally (vertical to leaf vein) and formed cork and silica cells pairs.The cork cells base were adjacent to the mesophyll cells while the silica cells were embedded top between cork cells and epidermal cells.(3) The leaves with short cells,macrocosmically,the back of leaves was bright and covered with waxy layer,and the staining character of epidermal cells changed from a microcosmic perspective.The mature cork cells were bread-shaped columnar cells while the silica cells were dumbbell flat cells.(4) When stomata apparatus opened,no K⁺ or H₂O₂ was in cork cells;when stomata apparatus closed,a large amount of K⁺ and H₂O₂ accumulation can be found in cork cells.The K⁺ and H₂O₂ accumulation in cork cells was consistent with those in subsidiary cells,while no K⁺ or H₂O₂ accumulation in silica cells and long cells.The generation time of short cells in epidermis of maize was identified in the study,and the morphological variation characteristics of the developmental process was showed,we also found that the accumulation of K⁺ and H₂O₂ in cork cells changed periodically along with the stomatal switch was found,moreover,it was consistent with those in subsidiary cells.

Abstract:A fumigation experiment was conducted to study the tolerance mechanism of Taxus media cv.hicksii to formaldehyde(CH₂O) stress.A year old cutting seedlings of Taxus media cv.hicksii were grown in an airtight fumigation chamber of 1 m³,and five treatments with various CH₂O concentrations(0,5,10,20 and 40 mg·m^-3CH₂O)were arranged by a completely randomized experiment with three replications.The results showed:(1)No significant injury symptoms were observed in the appearance until 1-day 40 mg·m^-3 CH₂O fumigation was done,and the injury symptoms were strengthened with time.(2)With the increase in CH₂O concentration,the contents of malonic dialdehyde(MDA),free proline(Pro)and relative electrical conductivity were enhanced significantly,while the soluble sugars(SS) were increased initially and decreased after 5-day fumigation.(3)The activities of superoxide dismutase(SOD),catalase(CAT),polyphenoloxidase(PPO) and glutathione reductase(GR)were induced as the first police line of removing active oxygen at 5 mg·m^-3CH₂O,however,PPO responded most immediately.While under 10-20 mg·m^-3 CH₂O concentrations,six enzymes worked together to remove active oxygen.Under 40 mg·m^-3CH₂O stress,all tested enzymes were suppressed in different degrees.The activities of ascorbate peroxidase(APX),PPO and GR were significantly reduced as compared with CK,otherwise the activities of SOD,peroxidase(POD) and CAT were significantly increased in comparision with CK.The result indicated that under lower CH₂O concentrations(5-20 mg·m^-3),Taxus media cv.hicksii could stand the CH₂O stress mainly through enhancing the levels of osmoregulation substance and scavenging effect of oxygen free radical.Under 40 mg·m^-3CH₂O concentrations,the activities of APX,PPO and GR were significantly suppressed.Meanwhile cell membrane lipid peroxidation was strengthened and plants had gotten hurt.In summary,Taxus media cv.hicksii could adapt to 20 mg·m^-3CH₂O polluted environment with no obvious damages.The condusions offer foundation of theory for the follow-on experiments about CH₂O purification ability and metabolic machiney of Taxus media cv.hicksii.

Abstract:To gain further understanding about the physiological and biochemical effects of Spd,we conducted the effect of spermidine (Spd) on induced resistance to powdery mildew in susceptible Cucumis melon variety ‘066’,‘0544’ and resistance variety ‘Yuntian-930’ seedlings.The activities of superoxide dismutase (SOD),peroxidase (POD),catalase (CAT),polyphenol oxidase (PPO),as well as chlorophyll a,chlorophyll b,total chlorophyll,carotenoid,hydrogen peroxide(H₂O₂) and malondialdehyde (MDA) contents were assayed in melon leaves after treated with Spd and inoculated with powdery mildew.The results show that:(1)the activities of four defense enzymes and the contents of photosynthetic pigments in melon leaves inoculated with powdery mildew were all raised at first,and then decreased.Furthermore,the content of MDA increased observably.(2)Spd mitigated the reduction of defense enzymes and the contents of photosynthetic pigments,and reduced the content of MDA and the disease index,and 1.0 mmol/L Spd had the best effects.(3) Foliar-spraying Spd made the content of H₂O₂ in melon leaves go up whether if inoculated powdery mildew or not.(4) Exogenous Spd had a wide spectrum on improving resistance to powdery mildew and the resistance could conduct upward.One idea is that H₂O₂ may act as a kind of transport signals for the induction resistance to powdery mildew by Spd in melon.In summary,the results indicated that Spd mitigate the powdery mildew stress which cause reduction of defense enzymes activities and photosynthetic pigment contents,increase plants photosynthetic capacity,and decrease disease index observably,then increase melon resistance to powdery mildew.

Abstract:This experiment was conducted with Clerodendrum trichotomum Thumb pollen.The effects of the storage mode,storage time and storage temperature,thawing way and precool way on C.trichotomum Thumb pollen germination were explored.In addition,the changes of the protective enzyme activities and osmoregulation substances content were estimated under -80 ℃ and 4 ℃low temperature storage process.The results indicated that:(1)the effect of two pollen storage ways with anther and powered at low temperature condition was not significant.The different precooling ways have no significant differences on the effect of low temperature storage.37 ℃ bath thawing is significant better than room temperature thawing for pollen germination under -80 ℃.(2) Germination rate of pollens still maintained at 7.99% after three months under -80 ℃,having improved the pollen germination more effectively.(3) With the low temperature stress counting,the activities of SOD and POD increased at the beginning then decreased under -80 ℃ and 4 ℃.(4)The content of soluble sugar under -80 ℃ and 4 ℃ and soluble protein under -80℃ increased at the beginning and then decreased;The content of soluble protein under 4 ℃ decreased continually.The study found that C.trichotomum Thumb pollen was subjected to be storage at -80 ℃.The pollen improved the cold resistance and contain its activity by enhancing the SOD activity,POD activity and soluble sugar content,soluble protein content when it was subjected to low temperature stress.

Abstract:Two photosynthetic subtypes of C₄ desert plants,including NADP-malic enzyme (NADP-ME) Salsola rosacea and NAD-malic enzyme (NAD-ME) S.subcrassa,were used to investigate the adaptive mechanism of C₄ photosynthetic enzymes and antioxidant enzymes in respond to soil drought stress.The results showed that:(1) leaf water content decreased as increasing of drought stress;(2) the phosphoenolpyruvate carboxylase (PEPC) activity increased markedly under moderate drought stress and decreased significantly under severe drought stress;the NAD-ME activity of S.rosacea and NADP-ME activity of S.subcrassa were very low,and their activities were almost not affected by drought stress;the NADP-ME activity of S.rosacea was declined with increasing of drought stress,but the NAD-ME activity of S.subcrassa increased firstly and then decreased significantly under severe drought stress;(3) the superoxide dismutases (SOD) activity was declined with increasing of drought stress,and the peroxidase (POD) activity increased under drought stress;the catalase (CAT) activity increased under moderate drought stress,but under severe drought stress,CAT activity of S.rosacea was declined,and that of S.subcrassa increased significantly;the malondialdehyde (MDA) content arose in different degrees as increasing of drought stress,and MDA content under severe drought stress was significantly lower than that under moderate drought stress.These results have showed that PEPC activity increased under a certain degree of drought stress;decarboxylase (NADP-ME and NAD-ME) belonging to two photosynthetic subtypes showed significant differences in response to drought stress;POD and CAT are the major antioxidant enzymes,but CAT for S.rosacea does not remove H₂O₂ efficiently under severe drought stress.

Abstract:The present work studied the effects of 10 mg/L cerium sulfate on the antioxidant enzymes and photosynthesis of tomato seedlings ‘Hezuo 908’ leaves under 80 mmol/L calcium nitrate stress.The results showed that,comparing with the control,calcium nitrate stress significantly inhibited the growth of tomato seedlings by reducing the height,stem diameter,fresh weight,shoot and root dry weight.Furthermore,calcium nitrate stress also led to the decreased activities of SOD,POD and CAT as well as the decreased net photosynthetic rate,stomatal conductance,transpiration rate and intercellular CO₂ concentration,whereas resulted in elevated MDA contents and membrane permeability.Comparing with the calcium nitrate stress treatments,however,after sprayed with cerium sulfate,some vegetative growth indicators,such as the plant height,stem diameter,fresh and dry weight were promoted in different degrees.In addition,the SOD,POD and CAT activities were also significantly up-regulated while MDA content and membrane permeability of leaves were greatly reduced.Meanwhile,the photosynthetic rate,transpiration rate and stomatal conductance were notably improved.Therefore,foliar spray of cerium sulfate helps to alleviate the damage caused by calcium nitrate stress through promoting the antioxidase activities,reducing the membrane lipid peroxidation and maintaining relative higher photosynthetic performance of tomato seedlings.

Abstract:Alfalfa （Medicago sativa）seedlings was conducted with 16 different salt-alkaline conditions (salinity 25-150 mmol·L^-1 and pH 8.39-10.90) by mixing four salts (NaCl,Na₂SO₄,NaHCO₃ and Na₂CO₃) in various proportions．We studied survival rate,plant height,total biomass,soluble protein content,proline content,ferulic acid and salicylic acid of alfalfa seedlings with Glomus mosseae under mixed salt-alkaline stresses by indoor pot experiment．Results showed that:(1)plant height,total biomass,soluble protein,proline content of inoculated plants were increased by 20%,130%,9.6%,3% respectively than non-inoculated plants under non- salt-alkaline stress conditions.While ferulic acid and salicylic acid were decreased by 59.1%,623.9% respectively than non-inoculated plants in natural conditions.(2) Under salt-alkaline stress conditions,whether or not inoculation of AMF（arbuscular mycorrhizal fungi）,the survival rate,plant height,biomass and soluble protein of alfalfa were decreased with the increase of salt-alkaline degrees.However the proline content,ferulic acid and salicylic acid content of alfalfa were increased.The survival rate,plant height,total biomass,soluble protein and proline of inoculated plant were better than non-inoculated plants with significantly different.Salicylic acid content of inoculated plant was lower than that of non-inoculated plants with significantly different and higher levels of ferulic acid but the difference was not significant.In conclusion,under mixed salt-alkaline conditions,inoculated AMF can change the content of phenolic acids,accumulate osmotic regulation substances,promote the growth and improve saline-alkaline tolerance of alfalfa.It is important for improving economic crops in the salt-alkaline soil and promoting AMF play a role in production.

Abstract:Collected the birch barks,branches and leaves of plant samples in four habitats of sunny slope,shady slope,forest edge and isolated trees in different diameters of Betula platyphylla in Huanglong mountain forest farm of northern Shaanxi Province in loess plateau,to illustrate the variation of betulin and betulinic contents.The samples extracted by ultrasonic assisted extraction,and used an accurate HPLC method to detect betulin and betulinic acid contents in different habitats and different diameters.The result indicated that there was a great variation between different habitats,and it was showed concretely as follows: (1) The contents of betulin and betulinic acid in barks and the contents of betulinic acid in branches ranged from high to low as shady slope,isolated trees,forest edge and sunny slope.The contents of betulin and betulinic acid in leaves and the contents of betulin in branches ranged from high to low as shady slope,forest edge,isolated trees and sunny slope.(2) The contents of betulin and betulinic acid in various organs of birch from high to low as bark,branch,leaf.(3) The betulin and betulinic acid contents of the different organs in different habitats increased first and then decreased with the increasing DBH of the trees,and the top value was observed in the DBH of 10.1-20 cm.The research suggested that shady habitat conducive to the accumulation of betulin and betulinic acid in various organs;the content of betulin in different organs of B.platyphylla is higher and the content of betulinic acid in different organs is lower,and betulin as raw material to prepare betulinic acid is an effective way to solve the betulinic acid in low levels of natural plants and difficult to extract;Attentions should be pay to grasp the opportunity of the organs of B.platyphylla,it is better to collect when the DBH of birch grows to 10.1-20 cm.

Abstract:Non-structural Carbohydrates (NSC) are not only utilized as energy sources in plant metabolism,but also as the adaptive mechanisms of plant species in response to the environmental changes.Using the anthrone colorimetric method,we measured the NSC content of leaves from 163 tree species collected from four typical forests,which were temperate needle broad-leaved mixed forest,temperate broad-leaved forest,subtropical evergreen broad-leaved forest,and tropical forest,in order to investigate the spatial patterns of leaf NSC along the latitudinal gradient and to explore the relationships between leaf NSC content and climatic factors (temperature and precipitation) on a large scale.The results showed that:(1) The soluble sugar,starch,and NSC in leaves decreased from north to south.For example,the NSC content of temperate needle broad-leaved mixed forests (170.79 mg/g)>temperate broad-leaved forest (100.27 mg/g)>subtropical evergreen broad-leaved forest (91.24 mg/g)>tropical forest (80.13 mg/g).(2) The soluble sugar,starch,and NSC contents of deciduous and broad-leaved trees were similar among different forests;and the order observed was deciduous trees>evergreen trees and broad-leaved trees>coniferous trees.Moreover,the soluble sugar/starch ratio was increased with latitude increasing (R²=0.85,P<0.01).(3) The contents of soluble sugars,starch,and NSC were negatively correlated with mean annual temperature (MAT) and mean annual precipitation (MAP) in the forests (P<0.001).Specifically,soluble sugars,starch,and NSC decreased as MAT and MAP increased.Our findings provide basic data for the carbon metabolism and adaptive strategies of plant species in forests;and provide new insights into the responses and underlying mechanisms of plant species to future climate changes.

Abstract:A pot experiment was conducted to investigate the plant growth,Cd content,Cd accumulation and nutrient uptake and transport in Ricinus communis (Zibima 5) when exposed to heavy metal polluted soil (100 mg·kg^-1) and different EGTA treatments (0,0.5,1,and 2 mmol·kg^-1).The results showed that:(1)compared with no EGTA treatment (E0),0.5-2 mmol·kg^-1 EGTA inhibited the growth of castor roots,decreased the fresh and dry weight of roots by different degrees,but had no significant effect on plant total dry weight.(2) EGTA can effectively promote the translocation of Cd from roots to shoots,2 mmol·L^-1 of EGTA treatment increased Cd contents in leaves by 41.34 times.The accumulation of Cd in the leaves increased significantly with elevation of EGTA doses.Compared with E0,the Cd accumulation in the leaves of EGTA treatments increased 14.0-45.6 times,and accounted for 36.89%~58.63% of the total plant amount,respectively.(3) EGTA had different effects on the mineral nutrient concentration in R.communis under Cd stress.EGTA promoted translocation of K to the shoots,while inhibited translocation of Mg to the shoots;Moreover,Ca contents in the roots,stems and leaves were increased under low dose of EGTA treatment,while high dose of EGTA decreased them.Zn contents in the leaves and Cu contents in roots and shoots were increased as EGTA concentration increased.Fe contents in leaves and roots,Mn contents in roots and shoots were significantly increased with increasing dose of EGTA treatments.Compared with no Cd control,EGTA can increase the available cadmium in soil,but reduce the absorption of K in roots.Therefore,Cd stress inhibits the growth of the plant,appropriate concentration of exogenous EGTA can significantly alleviate Cd stress in R.communis.EGTA changed the distribution of the accumulation of Cd in roots,stems and leaves of R.communis and improved the translocation of Cd from roots to shoots,especially to the leaves.It can strengthen the remediation efficiency of castor on Cd contaminated soil.K fertilizer should be applied to ensure the normal physiological metabolism of the plant.

Abstract:Through artificial shading treatment,fast chlorophyll fluorescence induction dynamics characteristics of three-year old peach cultivar ‘Baojiahong’ leaves were studied under five different light intensities(100%,80%,60%,40% and 20% of full sunlight) at different growth periods.The result showed that:(1)with the decreasing of light intensity,the maximum fluorescence gradually increased.(2) In terms of PSⅡ energy distribution ratio,the value of φ_Eo increased significantly under the lower light intensity,but the value of φ_Do decreased.(3) In terms of PSⅡ reaction center activity,the values of ABS/RC,TRo/RC,ETo/RC,DIo/RC decreased significantly under the lower light intensity.(4) At all the 3 growth periods investigated in this study,diurnal variations of the maximum photochemical efficiency (F_v/F_m) decreased at noon under all the 5 light intensity treatments;and the higher light intensity was,the more F_v/F_m reduced.This result suggested that peach leaves had photoinhibition at noon.The present study revealed that,under low light intensity,the antenna pigment of peach leaves had the reduced fluxes of both absorption and trapped energy,and PSⅡ reaction center activity decreased,while the enhanced energy distribution ratio of electron transport could improve the light efficiency.

Abstract:The experiment was conducted in pot with ‘Wuchuan’ and ‘Hunyuan’(biennial Astragalus mongholicus at greenhouse in Inner Mongolia University.The dynamic of rhizosphere microbial quantity and biomass on the two cultivars under continuous drought was studied through artificially controlling soil water content to stimulate drought condition.The results show that there are the obvious differences in bacteria,actinomycetes and fungi,and the microbial flora composition is dominated by bacteria,and then actinomycets .And along with continuous drought stress,bacteria and actinomycete amounts in the rhizosphere soil of two cultivar A.mongholicus first increased then decreased.However,the fungus amounts in the rhizosphere soil of A.mongholicus decreased continually comparing to the control.At the same time,the growth of A.mongholicus was inhabited by drought stress.The biomass in aboveground and roots parts of two cultivars A.mongholicus,root and leaf tissue relative water content all declined but R/S-ratio increased with the increase of drought intensity.Correlation analysis showed that the number of rhizosphere soil microbe had a significant positive correlation with aboveground biomass,but weak relation with roots biomass.The results indicated that the moderate drought improved the quantities of bacteria and actinomycetes,thereby altering the microbial community structure ,which is beneficial to the accumulation of aboveground biomass of A.mongholicus.

Abstract:Species biodiversity and water conservation ability of 4 types of forests (Choerospondias axillaris forest,Pinus massoniana untended forest,Pinus massoniana tended forest and P.massoniana-C.axillaris mixed forest) were compared by the methods of community investigation,soil and litter analysis in Qingyanghu State-owned Forest Farm.The results showed that:(1) 135 vascular plants were found in all 4 forests,which belongs to 97 genera and 58 families.Choerospondias axillaris forest had 88 species,ranked the first order in species richness of 4 forests;Pinus massoniana-Choerospondias axillaris mixed forest had 76 species,ranked the second order;P.massoniana tended forest had 64 species,ranked the third order;P.massoniana untended forest had 55 species,ranked the fourth order.(2)Forest type had an important effect on species diversity,both C.axillaris forest and the mixed forest had higher species diversity in herb plants than Pinus massoniana forests,but lower species diversity in shrub plants.(3)DCA results indicated that C.axillaris forest and the mixed forest had higher similarity than P.massoniana forest.(4)Forest type had an important effect on water conservation capacity.Compared to P.massoniana forest,the litter amount of C.axillaris forest and the mixed forest was decreased 10.1% and 15.2%,respectively;litter water retention increased 34.1% and 44.7%;the soil bulk density decreased 14.7% and 7.4% at soil depth of 0-10 cm,decreased 14.1% and 4.0% at 10-20 cm,and decreased 8.7% and 4.9% at 20-30 cm;the total water-holding capacity increased 15.8% and 4.5%,respectively.The results also showed that the water conservation capacity of P.massoniana forest was increased by ecological tending.

Abstract:Taking 7- and 11-year-old mixed Schima superba - Cyclobalanpsis glauca plantations(SC)(plantations were transformed from degraded shrub forest) and the reserved shrub forest(SF) in north subtropical areas of China as test objects,we analyzed the effects of stand age on the soil labile organic carbon content.(1)As compared with SF,the soil total organic carbon content(TOC),easily-oxidized carbon content(EOC) and light fraction organic matter content(LFOM) in both 7- and 11-year-old SC stands were increased by 22.79%-43.34% and 52.33%-96.13%,11.11%-25.18% and 57.89%-100.90%,18.18%-85.20% and 74.50%-93.75%,respectively.The water-soluble organic carbon content(WSOC) in 7-year-old SC were decreased by 4.10%-9.53%(except in 10-20 cm soil layer) and in 11-year-old SC increased by 0.71%-5.37% compared with SF.(2)The ratios of WSOC/TOC in the soils followed the order of SF>7-year-old SC>11-year-old SC,whereas the EOC/TOC in the soils followed the order of 11-year-old SC>SF>7-year-old SC.(3)In the three stands,soil WSOC,EOC,and LFOC had extremely significant correlations with soil TOC(P<0.01),and the correlation coefficients between WSOC and TOC were lower than others.The soil TOC,EOC,and LFOC in the three stands were extremely significantly correlated with soil nutrients,but the soil WSOC in SF had no significant correlations with soil hydrolysable N and available K.The soil organic carbon of evergreen broad-leaved young plantations transformed from shrub forest has changed significantly,and the long-term effect of stand age on the soil organic carbon accumulation need to be further studied.

Abstract:The research of plant species diversity has a great impact on ecological construction.With the vegetation data of field survey,we studied the desert steppe community composition and structure in sandy area of Eastern Ningxia,the vertical variation of species diversity,and canonical correspondence analysis (CCA) the contact between plant community distribution and soil character.The results showed that:(1)the species of desert steppe in sandy area was simple,with only 6-13 species.There was a significant difference between aboveground and coverage in different community types.The weak competitive species in community decreased,and the dominants have higher important value.(2)The species diversity index was significantly different among communities,but the variation tendency was not consistent.The correlation coefficient between diversity index and richness index,evenness index were 0.975 7 and 0.880 2,respectively,but the correlation coefficient of dominant index is -0.519 8.(3)In the analysis of CCA,the content of soil moisture,organic matter and NPK were higher.Soil bulk density lower,plant species abundance,relatively;soil moisture,soil bulk density and soil organic matter played a leading role in community distribution,the correlation coefficient are -0.742 8、0.683 8、0.532 9,respectively.Species and community both in the axis of CCA about soil factor relevance have a consistency.The results indicated that,the dessert steppe plant in sandy area of eastern Ningxia,dominants have extremely status and roles;the contribution rate of species richness to plant diversity is greater than that of evenness to plant diversity;soil moisture plays a decisive role to plant community distribution in this area.

Abstract:The technique for mesophyll protoplasts isolation and purification of a triploid poplar variety,Populus alba×P.berolinensis Yinzhong,was studied,for further genetic improvement through cell fusion and transgenic engineering.The leaves of aseptic seedling were used for mesophyll protoplast isolation and purification.The results showed that the yield and viability of the protoplasts were significantly influenced by the concentration of enzyme mixture,osmotic pressure and incubation time.Under the optimum condition for mesophyll protoplast isolation,CPW+3% Cellulase RS+0.5% Macerozyme R-10+0.3% Pectinse Y-23+0.6 mol/L mannitol+0.6 g/L MES+1 g/L BAS with 8 h incubation in dark,the protoplast yield could reach up to 2.13×10⁷ per gram of leaves and the viability could be 80.18%.The best purification method was rising with sucrose density centrifugation.The yields were up to 1.06×10⁷ protoplasts when purified with sucrose at the concentration of 40%.The protocol could meet the demands of protoplast culture-based techniques.

Abstract:The paper reports a new record genus of Boraginaceae,Microcaryum,and a new record species,Microcaryum pygmaeum (Clarke)Johnst.,in Xizang.M.pygmaeum growing in the altitude of 5 000 m,was found in the alpine meadow of Longzi Xizang.The characteristics of its external morphology,nutlet and pollen epidermal micromorphology were studied in detail,and the differences between it and the related species Lasiocaryum densiflorum (Duthie)Johnst.were presented in the paper.The voucher specimen is deposited in the herbarium of Beijing Normal University(BNU).

Abstract:Seven new records of plants from Chishui Alsophila National Nature Reserve in Guizhou are reported.They are Didymocarpus stenanthos Clarke,Aeschynanthus acuminatus Wall.ex A.DC.,Pinellia integrifolia N.E.Brown,Mitreola reticulata Tirela-Roudet,Calanthe clavata Lindl.,Staurogyne sichuanica H.S.Lo and Pentasacme championii Beth.,and the two genera,Staurogyne and Pentasacme,are newly recoded in Guizhou Province.The new geographical distribution of these plants have a great significance to the flora and the vegetation of Danxia Landform in Northern Guizhou.

Abstract:Primula filchnerae Knuth is one of the extremely endangered plants of the world.Since its being collected by W.Filchner in 1904 on the southern lopes of Qinling Mountains (Tsinling Shan),it has never been found again in the wild.In 2006,it was rediscovered in Hubei Province.This year we found several individuals at its type locality in southern slopes of Qinling Mountains,and added some floral details and habitat description of this plant.

Abstract:This paper revises Gyroweisia yunnanensis,an endemic species of China,based on the study of type and relative specimens.According to type characters,all specimens that have been assigned to G.yunnanensis are re-examined,so that the current distribution could be confirmed in Yunnan,Liaoning and Inner Mongolia,of which Inner Mongolia is a new geographic distribution.Description,detailed note and digital photograph are provided,and the type is refigured in drawing.This paper will provide new references to Pottiaceae of China.

Abstract:Based on the study of Kindbergia Ochyra in the world,a revision of Chinese Kindbergia was carried out.Results showed:(1)“K.arbuscula(Broth.)Ochyra”,“K.praelonga(Hedw.)Ochyra”,and Bryhnia serricuspis(Müll Hal.)Y.F.Wang & R.L.Hu previously reported from China are conspecific with K.dumosa(Mitt.)Ignatov & Huttunen.(2)The set of characters of somewhat dendroid plant habit,dimorphic leaves,strong and nearly percurrent costa and distinctive leaf base decurrency did not fit well those of the existing genera in the Brachytheciaceae.Thus,all Chinese ‘Kindbergia’ species were transferred into the new monotypic genus,Pseudokindbergia M.Li,Y.F.Wang,Ignatov & B.C.Tan.(3)Pseudokindbergia differs from Kindbergia in having semi-orbicular to orbicular-triangular,obtuse or truncate pseudopar aphyllia,conic-apiculate operculum,and inclined capsules.(4)Up to date,no Kindbergia species has been found in China.