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- Abstract：Magnetic Au-Fe3O4 nanoparticles(NPs) were prepared and their surfaces were modified with a carbohydrate, lactose(Lac), which have binding capability to a lectin RCA120.Characterizations of the resulting glyco-NPs(Lac-Au-Fe3O4) reveal that they have uniform dumbbell-like shapes(8+14 nm) with Lac residues coupled to the Au components.The Lac-Au-Fe3O4 NPs showed good solubility allowing a fast and full interaction with RCA120 in an aqueous solution within 30 minutes.By applying a magnetic field,RCA120 was further isolated from the solution with the highest rate of separation at approximately 70%.Such purification could be achieved even when the concentration of RCA120 was as low as 1 nmol/L.These results demonstrated that the potentials of carbohydrate-functionalized Au-Fe3O4 NPs in rapid and fast purification of lectins,which are commonly found on the surface of many pathogens,thereby providing a baseline for the further studies on microbial purifications by this new promising material.Keywords：magnetic nanoparticles;carbohydrate;lectin;pathogens0|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Metagenomic DNA was extracted from a human fecal sample and DNA fragments around 40 kb was isolated and purified.A fosmid library containing approximately 30 000 clones was created.Restriction analysis by EcoR I revealed a high diversity of the cloned DNA fragments and the estimated average insert size of the library was 40 kb.Tributyrin was used as substrate for activity-based screening of the library and one lipolytic enzyme positive fosmid clone was obtained.The lipolytic gene sequence was obtained after subcloning and sequencing,which showed high homology to the patatin-like phospholipase from Pyramidobacter piscolens W5455 with an amino acid identity of 95%.This is the first report of function-based metagenomics on screening of lipolytic genes from human gut microbiota.It also provides food industry with a new source of lipolytic genes and screening method.Keywords：metagenomics;gut microbiota;patatin-like phospholipase0|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Drought,high salinity,insect pest,and disease have adverse effect on the yield and quality of crops.Ethylene responsive factors (ERFs) are involved in plant response to abiotic and biotic stress.In this study,according to the sequence of an ERF family gene W17 from wheat,the W17 RNAi expression vector Pahc25-W17RNAi containing inverted-repeat sequences of W17 was constructed and transformed into wheat variety Xinchun 9 using particle bombardment.In total,2379 embryos were bombarded.A total of 115 regenerated plants with resistance to Bialaphos were obtained.Among them,12 transgenic lines with Bar gene were identified.Semi-quantitative RT-PCR showed that the expression of W17 gene and its downstream genes decreased significantly.Meanwhile,phenotype appraisal found that the growth of transgenic wheat in seedling stage was also inhibited.This study is useful for deep analysis of the function of ERF genes and preliminary investigation into the mechanism of ERF proteins;furthermore,it establishes the foundation for improving the wheat resistance by molecular breeding.Keywords：wheat;transgenic;genetic transformation;ERF(ethylene responsive factors);RNA interference1|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The objective of this study is to analyze the influence of the over-expression of OsGA20ox2 on rice plant architecture.OsGA20ox2 gene was amplified by reverse transcription polymerase chain reaction(RT-PCR)and an over-expressing binary vector pS12Q based on the OsGA20ox2 gene was constructed.Though Agrobacterium-mediated transformation of rice,taller transplants were obtained.In T0 generation,85 lines were obtained and checked by amplification of Hyg gene.Two of them showed specific band by PCR and taller in height.In T2 generation,compared with control lines,taller lines increased by 9.4%;the panicle neck length increased by 15.62%;the length of the first internode(counted from the top)increased by 8.46%;the panicle length increased by 7.98%,the seeds per panicle increased by 6.8%,the tiller number increased by 12.5%;the 100-seed weight increased by 2.6%;and the flowering time was 10 days earlier than that of the control.Moreover,the fecundity of the transgenic plants was improved and their growth cycles shortened.Based on RT-PCR analysis of OsGA20ox2 in stem,two taller lines showed stronger expression compared to their wild counterpart.These results showed that over-expression of OsGA20ox2 gene improved rice architecture,and suggested that OsGA20ox2 is essential for panicles and stem development.Keywords：rice;OsGA20ox2;over expression;tall;development3|9|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Effects of collocation modes of three hybrid varieties on growth and total yield of early and late rice under field plot conditions were studied in the present paper.The collocation modes of hybrid varieties including Tyou705-Xiangfengyou103 (M1),Jinyou974-Fengyuanyou272 (M2),Jinyou402-Tyou6135 (M3) were designed and a conventional variety collocation mode (Xiangzaoxian 45-Xiangwanxian 12) was used as control.The results showed that the leaf area index (LAI) of early and late rice between different varieties was following M3>M2>M1>CK.The order for dry matter accumulation of root at active tillering stage and full heading stage was M1>M3>M2>CK,whereas the order for dry matter accumulation of stem and leaves at filling stage and mature stage of early rice was the same as that of LAI.The order for dry matter accumulation of root at full heading stage,filling stage and mature stage of late rice was M3>M1>M2>CK.As far as the growth duration was concerned,M1 and M2 collocation modes were safe for full heading and total rice yields could reach to 16 189.3 and 15 494.7 kg/hm2,equals to 25.01% and 19.65% higher than that of the control,respectively.The results indicated that the collocation modes of early and late rice with early and middle growth durations were the optimal modes to produce the highest annual rice yield.Keywords：double-season rice;variety collocation;leaf area index;dry matter accumulation;yield5|9|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：After seedlings of different wheat varieties in Shanxi at the two-leave stage were stressed by PEG-6000 for 72 h,the physiological and morphological indexes were measured,which including maximum root length,ratio of root to shoot,relative water content of leaves,relative electric conductivity,SOD and POD activity,MDA content.Drought resistance of wheat at seedling stage was analyzed by fuzzy subordinate function and drought-resistance coefficients.The relationship between physiological and morphological indexes with drought resistance was studied using grey correlative degree.The results of the study showed that on drought stress conditions,maximum root length,ratio of root to shoot,relative electric conductivity,SOD and POD activity,MDA content in the 9 wheat varieties were higher than those of controls,but the relative water content of leaves was lower than that of control.The differences were significant or very significant.The drought resistance strength at seedling stage in different wheat varieties was baiheshangtou > jinmai47 > zhuganqing > siyuehuang > xiaohongmai > denglonghong > hongpidongmai > xinxiandongmai > zhongmai9.SOD activity was with highest correlative to drought resistance at seedling stage and next was maximum root length.3|9|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Land surface model provides with a good way for monitoring regional farmland soil moisture.The improved parameterization scheme of winter wheat-summer maize farmlands in the model is critical for accurately simulating soil moisture of the agricultural regions.This study focuses on prediction of soil moisture and presents the improved solutions.In particular,we incorporated the parameterizations of irrigation and winter wheat-summer maize cropping regimes,reselected total soil depth and the depths of the nodes of the different soil layers,modified the vegetation and soil hydrology parameterizations and replaced the invariant parameters of canopy top and bottom heights with crop morphological data.Subsequently,to assess the performance of these modifications,a set of offline simulations were carried out at three agricultural experiment stations (Dongbeiwang/Luancheng/Hongmen) in Haihe river plain.The results showed that the improved CLM3.0 model had better applicability in winter wheat-summer maize cropland,and could capture well the major characteristics of the observed total variations of soil moisture.In comparison with simulated soil moisture before model improvements,the root mean square errors decreased by 45.2%,47.1% and 51.5% at Dongbeiwang,Luancheng and Hongmen Experiment Stations respectively.Keywords：community land model;winter wheat-summer-maize;cropping system;farmland irrigation;parameterization scheme;soil moisture0|9|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：A 3-year field trial was carried out to estimate the water-saving potential for reducing the use of ground water resource through adjusting cropping production systems in North China Plain (NCP).Results showed that:1) Double cropping production system had advantage in kernel yield,but it consumed huge amount of groundwater,and the water use efficiency was lower.2) In continuing spring maize system,no irrigation was applied,as precipitation could almost fully meet the demand of spring maize and recharge the groundwater,while the total kernel yield was much lower than double cropping production system.Improving the yield of spring maize in this area would be helpful to the extension of the new cropping system.3) Compared with double cropping production system,the total kernel yields and amount of irrigation water were reduced by 11% and 48% separately in 'three harvests in two years’ production system.The results indicated a new way to develop a sustainable production system for water-saving agriculture,based on food self-security,in NCP.Keywords：crop;cropping production system;water use efficiency1|9|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Temperature rise will accelerate the soil water evaporation,and also induce salinization degree to some extent.Meanwhile,the irrigation water usage showed a downward trend as a result of the decrease of diversion from Yellow River to the irrigated district and more implementation of local water-saving projects.As such,it will be of significance in relation to soil salt variations in the context of climate change,so as to prevent worsening salinization and establish reasonable water-saving schemes.This paper analyzed the climatic data as well as soil salt data from fixed site observation during the last 18 years.The results showed that the soil total salt contents in the irrigated district presented a significant upward trend with the increase of temperature;as the temperature increased by 0.5-3.0℃ (in the future 10-60 years),the increment of soil total salts was estimated to be 0.03-0.28 g/kg and the relevant irrigation requirements for leaching the soil salts in fixed observation sites will then be around 682.16-2 171.20 m3/hm2.Keywords：climate warming;soil total salt;Hetao irrigation area;water saving irrigation;ecological environment0|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The purpose of the study is to explore the effects of different fermentation modes on the composting process and compost quality,using intermittent aeration mode,regulating aerobic fermentation and anaerobic fermentation time and alternate cycles in the compost through the control of oxygen content of the compost,and taking investigation of compost property changes,compared with pile-turn treatment.The results showed that both of the intermittent aerating and manual pile-turning treatments can increase oxygen content of the compost effectively (in the pile-turning mode,the oxygen content of the compost got up to 18.5%,and the oxygen content got up to 15.5% in the intermittent aeration mode),but at the end of the aerating or turning treatments,the oxygen content decreased rapidly,the oxygen of compost body can be depleted within 27 minutes by using the manual turning mode,and within 24 minutes by using the intermittent aeration mode.During the composting process,comparing with the turning treatment,the composting temperature reached room temperature about 10 days in advance by using the intermittent aerating treatment,and the moisture content of landfill reached a steady state about 18 days in advance.The intermittent aeration treatment can promote composting pH to be a neutral state in the mid and late composting process.At the end of the composting,the composting material decreased 51.3% and 44.6% by using the intermittent aeration treatment and the overturn treatment respectively,and the total nitrogen content was found to be stable at 1.66 mg/g and 1.62 mg/g respectively with the above two treatments.Therefore,compared with traditional turning mode,the intermittent aeratiing treatment can promote the compost to reach a steady state quickly,shorten the maturity cycle,and save energy compared with continuous aeration treatment.Keywords：compost;intermittent aeration;turning;oxygen content;compost maturity15|12|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The ‘3414’ design was used to study the effects of different levels of nitrogen(N),phosphorus(P),and potassium(K) on the yield and matrine content of Sophora alopecuroides L.The results showed that:1) three fertilization combinations (N+P+K,N+P and N+K) have the largest correlationships with the yield of Sophora alopecuroides L.,single application of N,P,K,and P+K have less influence; 2) according to the fertilization mathematic model,the optimum fertilization for N,P,K based on the largest yield which can reach to 2 016.75 kg/hm2 were 134.85,91.00 and 59.90 kg/hm2 respectively; 3)The optimum fertilization for N,P,K based on the matrine content of different parts should be defined as N 125-180 kg/hm2,P2O5 80-90 kg/hm2、K2O 10-45 kg/hm2.0|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Growing degree-day (GDD) is an important indicator for assessing regional heat resources and timing phenol-stage process,and correct GDD calculation is the basis of water and fertilizer management in agricultural production and accurate simulation and prediction of crop growth and development in crop models.In this paper,two popular methods of calculating GDD based on assumption of linear response of growth and development to temperature (LR assumption) and daily extreme temperatures were reviewed,and a growing degree-hour (GDH) method of calculating growing degree-days was introduced.Hourly temperature was estimated by diurnal temperature curve simulated by sine wave based on extreme temperatures.Theoretical argument showed that daily average temperature method may result in an over- or under-estimated GDD,and daily extreme temperatures method may result in an over-estimated GDD;Case study showed the GDH method had the smallest error comparing with the true GDD in three methods.To calculate accurately GDD,GDH method is recommended strongly when GDD is calculated by extreme temperatures based on LR assumption.Keywords：growing degree-day;LR assumption;sine wave simulation;diurnal temperature variation;growing degree-hour0|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The full-length cDNA sequence of MzSTO gene was isolated from a cDNA library of Malus zumi.The full-length cDNA of MzSTO was 1 066 bp.The 5'-UTR and the 3'-UTR were 49 and 288 bp respectively.Its open reading frame of 729 bp encoded a protein of 242 amino acids.There were two B-box zinc-finger domains (CX2CX8CX7CX2CX4HX8H) near N-terminal.MzSTO was induced by low temperature stress and repressed by high-salinity and drought treatment,which was,also responsive to ABA (abscisic acid) treatment by semi-quantative RT-PCR.All the results showed that MzSTO was involved in response of abiotic stresses including salt, drought and cold stresses through a possible ABA-dependent pathway in Malus zumi.1|10|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Field assessment of black spot resistance in 50 rose cultivars was made and disease resistance was classified.The authors aim to find out the reasons that the resistance to black spot disease differs among different rose cultivars and screen out the cultivars with resistance to black spot disease,and thus to provide the foundation and accumulate experience to breeding work which aims to promote the resistance of rose cultivars.The results showed that the Chinese rose is divided into 5 variety types including 5 high resistant varieties (HR),15 medial resistant varieties (MR),12 low resistant varieties (LR),14 susceptible cultivars (CS),and 4 serious susceptible cultivars (SS).The author also analyzed the effect factors in rose resistance and indicated that climbing Chinese rose,pink Chinese rose,triploid Chinese rose had stronger resistance,which is useful to the study of disease resistance of rose breeding.Keywords：rose;black spot disease;cluster analysis;resistance5|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The resistance of Xinjiang wild Myrobalan plum to Meloidogyne incognita was studied through the artificial inoculation.The effects of nematode infection on the activities of the related enzymes were investigated and compared between the nematode-resistant and susceptible plants.The morphological development of root knot formed by Meloidogyne incognita was studied.Resistance segregation was observed between the wild Myrobalan plum plants.Most of them were susceptible while 28% were resistant to Meloidogyne incognita.The phenotype was related to the gene psoRPM1.The activities of CAT and POD were rather higher in the resistant variety than susceptible ones,which might imply that they possibly played roles in the resistant process.Compared to susceptible plants,the activities of PPO and PAL in resistant variety were higher than 7-14 DAI (days after inoculation),then maintained at a same level.The root-knot nematode migrated through the cortex to the stele.Microscopic analysis of samples at 10 DAI showed that some giant cells exsited in the infected roots.As the development of giant cells,root knots were observed 22 DAI.Some giant cells in plants were devoid of any cytoplasm in 30 DAI.2|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to evaluate the resistant value of Prunus divaricata Ledeb germplasm resources,the pot seedlings of Prunus divaricata Ledeb were inoculated with root-knot nematodes of Meloidogyne hapla and Meloidogyne arenaria.The results showed that 0.16 % and 0.03% of the second stage juvenile nematodes(J2) in all inoculation J2 of M. hapla and M.arenaria were developed into female adults in the following 30 days after artificial inoculation.Prunus divaricata Ledeb was highly resistant to the root-knot nematodes of M. hapla and M. arenaria according to the resistance evaluation standard.The immune,highly resistant and middle resistant genotypes to M. hapla were found in Prunus divaricata Ledeb,being 46%,48% and 6% of the seedlings respectively.The immune,highly resistant genotypes to M. arenaria were found in Prunus divaricata Ledeb,being 56% and 44% of the seedlings respectively.It was found that 1.2% and 0.4% of inoculation nematode quantity were penetrated by M.hapla and M. arenaria respectively and 87% and 92.7% of the penetrated nematode population were not developed into female adults and no eggs were found on any root surfaces of the materials.The high resistance of Prunus divaricata Ledeb to M. hapla and M. arenaria was segregated in seedlings.Prunus divaricata Ledeb was one of resistant species and germplasm resources for root-knot nematodes of M. hapla and M. arenaria because it could resist penetration and delay the development of juvenile nematodes.The resistance of penetration,upgrowth and breeding is the major resistance mechanism.2|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aim of this research is to probe further into the anthocyanins metabolism and functions of enzymes involved in the synthesis of anthocyanins in strawberry fruits.The coding sequences of three genes encoding DFR,ANS and LAR were cloned from ‘Albion’(Fragaria×ananassa) strawberry fruits by RT-PCR.The predicted protein sequences shared 99%~100% homology to those of ‘Queen Elisa’ and ‘Korona’(Fragaria×ananassa) strawberry published in NCBI.Semiquantitative RT-PCR showed that DFR had three transcript level peaks at fruitlet stage,white stage and red stage,respectively,with the highest at red stage.The transcript level of ANS increased rapidly from white stage,reaching the highest at red stage.The transcript level of LAR showed a decreased trend with the highest at fruitlet stage.During the development of strawberry fruits,the transcript level of DFR peaks at fruitlet and red stages correlated with the concentration of flavan-3-nols and anthocyanins.The LAR and ANS were closely correlative with the synthesis of anthocyanins and flavan-3-ols,respectively.1|10|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The study focuses on the technology that can effectively extract total flavonoids from Malus micromalus Makino through enzymatic treatment,and on the investigation of the effects of flavonoid crude extract from Malus micromalus Makino on proliferation of HeLa cells in vitro.The four parameters,enzymatic concentration,treatment duration time,treatment temperature and pH value of enzyme solution were investigated respectively in four experiments,so as to get their respective impacts on the rate of total flavonoid extraction.The parameters of enzymatic treatment for total flavonoids from Malus micromalus Makino was optimized by the quadratic general rotation combination design.The influence of inhibitory action of flavonoid crude extract from Malus micromalus Makino on HeLa cells growth was also investigated by MTT assay.The results showed that the influencing sequence of the four parameters is enzymatic concentration,duration,and pH value of enzyme solution.And the optimized values of above four parameters for the maximum yield of total flavonoids are:0.25 mg/mL (the ratio of cellulase to pectinase is 2:1(g/g)),150 min,50℃,and pH 6.0,respectively.Under the optimized conditions,the experimental value of yield is (0.356 3±0.000 6)% (n=5),the experimental values agreed well with the estimated value of 0.360 0% with relative error 1.028%.Flavonoid crude extract from Malus micromalus Makino shows a strong inhibitory action on growth of HeLa cells in Vitro,with IC50 value of 109.89 mg/L.Compared with the traditional direct alcohol extract process,the optimized enzyme process can observably increase the extracting amount of total flavonoids.0|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：This work was aimed to obtain tetraploid Lilium pumilum DC with excellent ornamental traits and agronomic characters,and provide better cross parent for breeding of new Lilium variety.The seeds of Lilium pumilum DC (2n=2x=24) were treated with different concentrations of colchicine solution at different hours in order to figure out a proper method and obtain polyploids.The results indicated that the most effective induction was obtained by 0.1 % colchicine treatment for 24 hours with 30 % mutation rate.By chromosome observation of root tip,the tetraploid plants were successfully obtained with the chromosome number 2n=4x=48.The tetraploid plants showed obvious characteristics of low stoma density,large stoma,slow growth,thick and wide leaves and dark leaf color at the initial stage,but quick growth and large leaves at later stage.The results indicated that the polyploid plants were identified by phenotype,stomas and chromosome number observation.11|9|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：This study is to explore the effects of thermal stress on reproductive performance,blood reproductive hormones and genes mRNA expression to the country local variety and foreign cultivate layers varieties.Test choice body condition similar 16 Ninety-six sixteen-week Jining Bairichicken and 96 Hy-line variety Brown chicken were random grouped into optimum temperature group (25±0.26)℃ and High temperature group (38±0.26)℃ testing for 28 days.Each group has eight repeats with 6 chicken in each repeat.Ovary weight,follicle total and blood reproductive hormone concentration and reproductive shaft related gene expression mRNA relative quantity were determination at 112,119,126,and 140 days of age.The results show that:1) Ovarian and total follicular of the Hailan brown chicken developed better than which in Jining Bairi chicken under the optimum temperature conditions,however,Jining Bairi chicken and Hy-line variety Brown chicken appeared obvious ovarian development hindered,total follicle number hyperplasia slow (P<0.05) at 7th days of the heat stress.2) in the whole thermal stress period,high temperature group of follicle stimulating hormone (FSH) and luteinizing hormone (LH) hormone content significant change (P<0.05),heat stress after 7d estradiol (E2) was significantly reduced (P<0.05),progesterone (P4) increased at first,then dropped significantly (P<0.05);CRH level significantly higher than that of optimum temperature group (P<0.05), reed jining one hundred days chicken high temperature group of each blood reproductive hormone level of the coefficient of variation of the Hy-line variety Brown,and no significant difference (P>0.05).3) optimum temperature treatment group of reed jining one hundred days chicken GnRh,PRL,FSH-β,ESR,LHR,FSHR mRNA expression quantity are Hy-line variety Brown chicken,but no significant difference(P>0.05);and high temperature group reed Jining Bairi chicken mRNA expression quantity except outside PRL significantly Hy-line variety Brown chicken (P<0.05).The results indicate,local variety in thermal stress condition ovarian,total follicular development and the blood reproductive shaft relevant hormone secretion regulation function better than foreign varieties;And reproductive shaft relevant hormone mRNA expression quantity changes with various effect.Keywords：chicken;thermal stress;reproductive hormone;mRNA expression quantity;ovarian0|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：3α-HSD gene was amplified and cloned into the expression vector pET-15b.The constructed plasmid was over expressed in the host bacterial of E. coli BL21 after IPTG induction.Expression of 3α-HSD was optimized by bacterial culture temperature,concentration of IPTG and induction time.The engineering bacteria was lysed,and purified by ammounium sulfate precipitation,Ni-NTA affinity purification and molecular sieve separation.Enzymatic activity of expressed 3α-HSD was detected.Comamonas testosteroni 3α-HSD gene was cloned and expressed in the prokaryotic system.To reach the optimal expression,the recombinant E. coli need to be cultured at 37℃ and induced by 0.6 mmol/L IPTG for 4 h,while the medium containing 0.1 mmol/L Zn2+.The protein was purified through 60% ammonium sulfate precipitation,Ni-NTA affinity chromatography,and molecular sieve.A target protein with 99% purity was obtained which keeping enzyme activity.3α-HSD gene was cloned and highly expressed.It will build the foundation of antibody preparation and steroid detection in the water resource.Keywords：Comamonas testosteroni;3;α-HSD;inducing expression;purification0|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to confirm cellular localization on splenic lymphocytes of the mice,fluorophores was used to polysaccharide from Ganoderma applanatum (GAP)and fluorescence signal was detected indirectly to trace GAP.The reductive amination method was used in fluorescently tagged of Ganoderma applanatum polysaccharide(GAP).Fluorescein isothiocyanate was linked with reducibility terminatio of GAP,and fluorescent substitute ratio is detected by fluorescence spectrophotometer.The biological stability of GAP before and after fluorescently-tagged was measured by xCELLigence RTCA DP automatic real-time cell analyzer.The fluorescence signal of T lymphocytes,B lymphocytes and natural killer cell of spleen were detected by flow cytometry,and cellular localization was observed by fluorescence microscope.The results showed that there is no significant changes for the cytotoxic activity in vitro before and after fluorescent labeling of GAP,and its fluorescent substitute ratio is 0.90%.The results flowing cytometry showed that fluorescence signal could be detected by each FITC-GAP experimental group of T lymphocytes,B lymphocytes and natural killer cell of mice,and fluorescence signal intensity increased with the increased FITC-GAP concentration.Observed by fluorescence microscopy,FITC-GAP both surface and intracellular.GAP was located on the cell surface and transported to the cell nucleus of splenic lymphocytes for mice.Keywords：Ganoderma applanatum;polysaccharide;fluorescent labeling;spleen lymphocytes;cellular localization0|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To make clear insecticidal activity components from Jatropha curcas L.branch leaves.Using alcohol crude extract of petroleum ether partitioned extract from Jatropha curcas L.branch leaves as an experimental material in our investigation,and then silica gel chromatography,combined with PTLC preparation.At same time,the each stage of separated products was carried out by tracking activity,analysis by GC-MS,structure elucidation the main compositions of exhibited active components.The results show that the concentration of colony AJ1 reached 8 mg/mL,Myzus persicae(Sulzer)and Pieris rapae L.both corrected mortality exceeded 70% in 24 h(72 h),showed no significant differences with imidacloprid(70%),showed that toxic activity was very high.The colony AJ1 analysis using GC-MS,the results showed,nine compounds with maximum contents were identification,total amount up to 96.18%,the first five of maximum contents were 2-Propanol,1-(allyloxy),4-Quinolnol,4-ethyldecahydro-1,2-dimethyl-,4-(allyloxy)-2-methyl-2-pentanol,2,4-Dimethyldecane and 1-(hexyloxy)octane.The total amount of five main constituents reached 83.81%.Keywords：Jatropha curcas;petroleum ether partitioned extract;insecticidal components;biological activity;isolation and identification1|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：A reasonable value of 55 Hz for the natural frequency of Tetradacus citri Chen was obtained by using ANSYS,a large simulation software.A comparative study on the effects of resonating acoustic wave on behavior and lifespan of Tetradacus citri Chen was conducted in this paper,in order to verify the feasibility of prevention of Tetradacus citri Chen through resonating acoustic technique.The response of Tetradacus citri Chen were recorded and tested when they were exposed to a sound field with sound intensity of 120 dB and frequencies of 55,100,180 and 300 Hz for 30 minutes.The results showed that under low frequency acoustic conditions,the Tetradacus citri Chen performed discomfort reactions,such as head shaking,wings flapping,head and tail rubbing by their limbs,and moving to the areas of low sound intensity in the flask;while,under the resonating acoustic wave,Tetradacus citri Chen had a strong response of avoidance,and the effectively escaping rate was up to 36.48%.When Tetradacus citri Chen was exposed to a sound field with frequency of 55 Hz and sound intensities of 120,110,100,90 and 80 dB for 30 minutes,it found that the higher the sound intensity was,the more significant the avoidance;while,if the sound intensity was lower than 80 dB,there was no significant avoidance.The death statuses of Tetradacus citri Chen were investigated with exposure to a sound field of 55 Hz and 120 dB for 4 hours every day until all were killed.The results showed that resonating acoustic wave of high intensity have a significant impact on the lifespan of Tetradacus citri Chen and all the insects used in the experiments were killed after 5 days,comparing with the controls the final mortality increased by 42.80%.0|9|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to meet the requirement of variable rate pesticide spray based on machine vision by detecting the weeds among the corn rows,this paper presents an identification algorithm of weeds among multi-row corn based on rows’ width.After taking the image of 3-leaf stage corn vertically down to the crops over three corn rows,Q color component was extracted through Otsu method to reduce the impact of natural light.The span of 3-leaf stage corn rows in the image was determined by establishing the mapping of the graphical width with the corresponding actual corn row width.The detection of the weeds depending on the corn row mapping could reduce the false identification rate of the patch unconnected with the row and improve the recognition accuracy of the weeds.The weeds identification algorithm among multi-row corn was compared with crop centerline detecting algorithm in this paper based on two aspects of identification accuracy and speed.The results show that the weed identification rate and speed can amount to 89.2% and 197ms,respectively.This means the algorithm can fairly match the variable rate pesticide spraying based on machine vision system.Keywords：corn;weed identification;row width;YIQ color space;Hough transform0|16|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：For the promotion of cultivation of herbaceous bioenergy plant and production of biomass feedstock on marginal land in China,the evaluation of application potential of silver reed was conducted,including the analysis of production potential,biomass quality,biomass utilization potential and ecological effects,based on the practical activies of the large-scale cultivation of herbaceous bioenergy plant on marginal land in Beijing suburb.The results showed that the production potential of silver reed was 2.31 t·hm-2 on abandoned sandpits in Beijing suburb,accounting for 8.41% of that on arable land in Beijing suburb.With good biomass quality and ecological effect,its standard coal equivalent,biogas and cellulosic ethanol yield were 1.42 t·hm-2,289.99 m3·hm-2,0.59 t·hm-2,respectively,accounting for 8.38%,8.37%,8.15% of that on arable land in Beijing suburb.Silver reed has a great application potential on marginal land in the future.Keywords：marginal land;herbaceous bioenergy plant;silver reed;biomass;application potential1|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Topography is the basis for land use spatial pattern formation.This study analyzed the land use structure of Pinggu District from 1993 to 2008 and the land use change on the different classification of elevation,slope and slope direction.The results showed thatarable land,orchard,woodland were the main land use type of Pinggu District.The arable land decreased but both orchardand construction land increased.The land use change was significantly different between different classifications of elevation,slope and slope direction.Most conversions between arable and construction land occurred in the place with an elevation less than 300 meters and the slope lower than 15 degree.The conversion between woodland and grassland was mostly taken place in the sunny slope and semi-sunny slope,with the elevation between 300 to 800 meters and the slope lower than 8 degree.The conversion between orchard and grassland was mostly taken place in the semi-sunny slope,the elevation less than 300 meters and the slope between 2 to 25 degrees.The conversion between orchard and woodland was usually taken place in the semi-sunny slope,the elevation less than 800 meters and the slope between 2 to 25 degrees.Little conversion was found in the area of elevation more than 800 meters and slope larger than 25 degrees.The main conversion in this area was that woodland was changed into other land types.The dramatic land use change had a high correction with elevation,slope and slope direction in Pinggu District.The change in land use could be characterized by an increase of construction land and orchard but a decrease of arable land in the lower elevation and slope zone of Pinggu.There was a little change in land use with the increase of elevation and slope.Keywords：land use;DEM;elevation;slope;aspect0|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The purpose of this paper is to probe into the type,spatial pattern of land use in each region of rock property and to analze the effect and restraint of the rock property on the land use in Miyun county of Beijing.The used geological map (1:50,000) of Miyun county of Beijing had regional properties of the rocks s,and was vectorized by actual survey and Arcview GIS.Both maps of local land use and rock property region were united.Seven research areas were analyzed.The results showed that forest land occupied absolute superiority in land use structure of Miyun county,which was related to distribution of rocks.Complete degree of land use type was the highest.Superiority degree is very low in the area of Quaternary System sediments .It is concluded that the land use differences on the quantity structure and spatial pattern were affected to a great extent by the rock property.Keywords：rock property;land use;spatial pattern0|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to provide the scientific basis for disaster mitigation of the Yellow River Delta,this study constructed the environmental vulnerability index system of the Yellow River Delta,and proposed a quantitative method of the vulnerability assessment evaluation index.The environmental vulnerability evaluation and the analysis of spatial distribution pattern were based on GIS software platform.The analytic hierarchy process (AHP) was used to determine evaluation factor weightings.And the cause of vulnerability were analyzed.The results showed that the light environmental vulnerability accounted for 42.7%,the moderate 21% and the serious 24.9%.The spatial distribution patterns were hereby obtained.The marine area was weaker while the terrestrial land area was stronger.Most marine area was lightly vulnerable.The marine area in the north of Hekou district was slightly vulnerable.The vulnerability in the terrestrial area had a decreasing trend from coast to inland.The coastal zone was extremely vulnerable.The coastal area was seriously vulnerable.The riparian area of the Yellow River and inland were moderately vulnerable.Keywords：Yellow River Delta;environmental vulnerability;normalized;analytic hierarchy process;quantile method;geographical information system0|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to reveal the mechanism of urban-rural harmonious development of Beijing suburbs,this paper conducted the analyses of temporal-spatial structure change and industrial structure evolution for agricultural suburban areas in Beijing,comparing the year of 2000 with 2008.Results showed that,a) spatial changes of the industrial structural characteristics have taken place in the suburbs;b) various spheres of the agricultural suburban area have different spatial industrial structures due to their urban-rural functions;and c) in terms of the town system and the industrial development,there were spatial variations between suburb counties in Beijing.This paper concluded that although change of circularity structure of agricultural suburban areas in Beijing was not significant from 2000 to 2008,its industrial foundation had changed significantly.Details were as:a) industrial structure of agricultural areas in the plain outskirts have changed greatly under the effects of urbanization;b) in agricultural suburban areas of the plain as well as mountainous ecological conservation agricultural areas,spatial structure had changed only a little but their industrial structure and behaviors of the farmers have undergone various degrees of changes.Keywords：agricultural suburban areas in Beijing;socio-economic structure;spheres structure;spatial variation;Beijing14|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Based on the model of stochastic frontier production function,this paper made an empirical analysis on winter rapeseed's technology efficiency and its influence factors with a sample of 1707 farmers in different production scales in China.The study showed that the labor output elasticity of rapeseed production was 0.153 5,which meant it was still in the labor-intensive phase,and presented a "U" trend between rapeseed-cultivation scale and technical efficiency.If the technical inefficiency was eliminated,the average output of rapeseed would increase by 24.1%.The efficiency loss function showed that,for the small-scale producers,householders' age(-3.225,the estimated coefficients,the same below),labor force of engaged in rapeseed(-0.501),the times of technology training (-3.448),income levels(-0.567) and subcontract of farmland (-0.366)had positive impact on technical efficiency,meanwhile the scale of rural households(0.476),level of education(0.143) had negative effects.Whereas for the ultra-large-scale producers,the level of education(-0.251),the size of rapeseed cultivation(-0.171)and subcontract of farmland(-0.540) had positive impacts on technical efficiency,but householders' age(0.028),the times of technology training(0.240),outward employment or not (0.370)had negative effects.Keywords：rapeseed;technical efficiency;scale;stochastic frontier production function;efficiency loss6|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：A binary Logistic model was adopted to analyze the factors which may affect household's willingness of ecological migration based on 256 questionnaires collected from Ankang,Shaanxi.Results clearly indicate that family size,child dependency ratio,elderly dependency ratio and per capita net income have an important impact on the willingness of migration.The original living conditions including location of residence,housing material,the distance from the house to the town and the number of households living together can affect the willingness of migration.The attitude of relatives and neighbors,and the attitude of village cadres as a kind of social pressure can influence the willingness of ecological migration.In addition,farmers participating in the project of returning farmland to forests and its size also have an important impact on the household's willingness of migration.Keywords：rural household;ecological migration;migration willingness;influencing factors;logistic model;Ankang city0|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the egg price transmission mechanism between egg's main producing areas (Shandong,Hebei,Henan,Liaoning,Jiangsu) and main sales areas (Beijing),the variation of the egg's prices was investigated based on the local monthly egg price data from 2010 to 2012.Using the methods of unit root test,granger causality test,VAR model,impulse response analysis and variance analysis,the egg prices in main producing were found could predicate the egg price in main sales areas,but a month lag when fluctuations of egg price in eggs' main producing areas transmitted to egg price in Beijing.It was also found that the egg price fluctuation of Shandong had greatest impact on egg price in Beijing than that of other areas.In order to avoid the great fluctuation of Beijing eggs' price,some measures such as the epidemic prevention and control system in the eggs main producing areas should be taken to stabilize the prices,and improve the market circulation efficiency in eggs main sales areas,establish warning system between the main producing areas and sales areas.Keywords：egg;price;the VAR model;impulse response;analysis of variance0|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
