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- Abstract：Enzyme activities from a wheat straw aerobic-degradation-microbial community were studied by using DNS method. These enzymes have stable and efficient capacity to decompose 80% of straw cellulose. Cellulose and hemicellulose lost 0.78 g and 0.16 g respectively 10 days after decomposition with these enzymes. The excreted enzymes of microbial community were a group of enzyme complex community with the capacity of zymohydrolyzing different substrates. The maximum cellulase activity was 0.17 U/mL. The maximum xylanase activity was found on the second day with a concentration of 2.82 U/mL. The optimum temperature for xylanase was 50 ℃, while the maximum tolerant temperature was 60 ℃. The optimum pH for xylanase was 7.0. At pH≤5 the xylanase activity was severely inhibited. Xylanase activity dropped quickly 6-20 min after initiation of the enzyme reaction. Afterwards until 120 min, xylanase enzyme activity dropped slowly. Zero point five milliliter centrifugal supernatant on the third day could saccharificate xylan substrate (22.5 mg/0.5 mL) of 6.76 mg with the transfer ratio of 33.8% in two hours under the optimum conditions of xylanase activity.Keywords：wheat straw;microbial community;aerobic degradation;xylanase7|6|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：The experiment was conducted under two water levels: no stress (75%-80% of field capacity), stress (30%-40% of field capacity). The changes of growth and photosynthetic system characters of tomato were investigated. The results showed that, under the water stress condition, the growth of the plants was inhibited, leaf water potential and leaf relative water content decreased. The total plant dry weight declined significantly and the reduction was 59.36% for Meifen-2 and 51.17% for Hongsheng, respectively. The root/shoot ratio increased 37.93% for Meifen-2 and 29.17% for Hongsheng. The net photosynthesis rate (Pn), stomata conductance (Gs), transpiration rate (Tr), intercellular CO2 concentration (Ci), the actual photosynthesis efficiency of PSII in the light (ΦPSII), the electron transport rate (ETR) and photochemical quenching (qP) decreased whereas the non-photochemical quenching (NPQ) and water use efficiency (WUE) increased. The stomata became smaller and the density decreased, most of them closed. The chloroplasts became round in shape, the lamellae arranged disorderly and the number of starch grain decreased or disappeared.Keywords：chlorophyll fluorescence;chloroplast ultrastructure;photosynthesis;stomata character;tomato;water stress5|1|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：Effect of different out-store tests after ice-temperature preservation on the cell wall components and the activities of related enzymes of the 'Okubao’ peaches (Prunus persica L. Batsch.) was investigated. It was found that the good fruit rate remains high under low-temperature chain storage condition, and the value of fruit firmness remains at 12.43 kg/cm2 after 14 days of periods of out-store. Meanwhile, the values of fruit firmness of progressively warming and intermittent warming treatments are 3.45 kg/cm2 and 3.33 kg/cm2 respectively, whereas the control is 2.98 kg/cm2. This may be due to: the activities of the polygalacturonase (PG) and pectinesterase(PE) are reduced under low-temperature chain storage condition, and to lower the contents of soluble pectin and the loosely bound matrix glycans, thereby the value of the fruit firmness remained at the similar level. However, the low-temperature chain storage condition had no apparent effect on the activities of polyphenol oxidase(PPO) and peroxidase(POD).1|1|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：A CONSTANS homologous gene named FaCO was cloned from young leaves of strawberry (Fragaria ×ananassa Duch. cv. 'Camarosa’) by RT-PCR and RACE technology. The gene had a cDNA sequence with 1 475 bp in length and contained an open reading frame of 1 152 bp which coding a deduced 384 amino acids protein. The peptide had two B-boxes, a CCT domain and a COOH region shared highly homology with CO of other plants, especially with CO of Populus deltoids, to 80%. The pGEX-4T-1/FaCO prokaryotic expression systems were constructed and induced. SDS-PAGE analysis showed that the rFaCO molecular weight was about 60 ku.Keywords：CONSTANS;gene;Fragaria×ananassa;cloning;expression analysis0|1|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：This paper is concerned on the effect of methyl jasmonate (MJ) treatment method on Oriental Lily 'Sorbonne’. The measuring parameters included plant height, florescence, bulb perimeter and phytohormone content of leaves. The result showed that bulb soaking with MJ induced in early flowering. Plant height reached 87.92 and 87.67 cm by spraying 0.1 and 1.0 mg/L MJ during squaring period plant, which were significantly higher than control. Spraying 1.0 mg/L MJ during squaring period prolonged florescence per plant and inflorescence of population by 2.09 and 3.25 d, enlarged the bulb perimeter by 1.66 cm. However, MJ treatment had no significant effects on either flower life or the number of flower per plant. The suitable concentration of MJ was 1 mg per liter. There were significant positive relationships among plant height, florescence per plant, bulb perimeter and IAA and IAA/ZR.Keywords：methyl jasmonate;Oriental Lily;growth and development;phytohormone1|1|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：Microstructure features of ramie seed were studied by using optical microscope and scanning electron microscope. The composition and content of fatty acids,yield and physicochemical properties of ramie seed oil were systematically measured with GC-MS. The potential application of Ramie plant seed in industry could be further exploited. The ramie seed shapes were variable. Their ornamentations were mainly in retiform-wrinkles and linear-wrinkles forms. The kernel weight,length and breadth of ramie seed were 0.034-0.049 g、0.455-0.694 mm and 0.250-0.322 mm respectively. The seed oil contents were between 13.45%-28.19%. Maximum oil was produced when the seeds were extracted with petrol ether at 80 ℃ for 12 h. There was a significant genotype difference between wild and cultivated type. Normally, wild type produced higher oil content. The major fatty acids of ramie seed oil were palmitic acid,stearuc acid,oleic acid,linoleic acid and linolenic acid. Under this condition, maximum total unsaturated fatty acids could reach 87.82%-93.69%. A significant positive correlation was found between seed oil yield and weigh and length (P<0.01). Similar significant positive correlation between seed oil yield and breadth was also evidenced (P<0.05).0|1|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：Taxus (Taxus cuspidata Sieb. et Zucc.) seed is of deep embryo dormancy. In this study Taxus seed was treated with three temperature stratifications of changing temperature of day and night (20 ℃/10 ℃,day/night)-cold (4 ℃),warm(20 ℃)-cold(4 ℃),cold(10 ℃)-cold(4 ℃). The results showed that the length and width of embryos treated for 6 months were increased from 1.52 and 0.47 mm to 1.95 and 0.61 mm respectively. The content of soluble sugar increased to 46.3 mg/g, but crude fat decreased by 3.8 %. Dehydrogenase activity (TTC) at 10 months was 2 times as high as that before treatment. The activity of glucose-6-phosphate dehydrogenas (G-6-PDH) decreased at anterior phase but increased at latter phase. Adenosine triphosphate (ATP) content was steady with a low level at the first phase, but remarkably increased at the second phase, 3.9 times higher than the initial value. The percentage of breached seeds and germination rate of changed temperature-cold stratification were 11.4 % and 14.7 % respectively, and significantly higher than that of warm-cold and cold-cold stratification. It is indicated that the changing temperature of day and night-cold stratification was more effective to break out seed dormancy than warm-cold and cold-cold stratification.3|1|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：This study was conducted to evaluate effects of different melamine dose levels on In-vitro rumen fermentation in a batch culture and cumulative gas production by using rumen fluids of Simmental × Luxi yellow crossbred cattle and high-concentrate feed as the substrate. The fermentation characteristics of the control group (0 mg/kg) and the test groups (2, 6,18, 54, 162 and 486 mg/kg) were determined after the 72 h incubation. There were significant reductions (P<0.05) of ammonia N and amino acid N concentrations at the dose levels of 2 mg/kg and 6 mg/kg melamine. The melamine addition at low dose level of 2 mg/kg also significantly reduced the total volatile fatty acids (VFA) production (P<0.05), but it didn’t alter the VFA pattern in molar proportions. The melamine had a decreasing trend on the total cumulative gas production, and it significantly enhanced the greenhouse gas of CH4 production (P<0.05). These results indicated that the dose of melamine didn’t favor the production of ammonia N and amino acid N and volatile fatty acids, suggesting an inhibitory effect of the melamine on microbial fermentation in the rumen. Additionally, the increase of CH4 in melamine addition group implicates feed energy wasting and is harmful to environmental protection. Therefore, the melamine should not be considered as an effective non-protein nitrogen source in ruminants.1|1|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：This study was conducted to determine the effects of steam-flaking of corn and supplemental live yeast on lactating performance and blood parameters of dairy cows. Thirty Chinese Holstein lactating cows were randomly allocated to three different dietary treatments:typical corn (Control), steam-flaked corn (Treatment 1) and steam-flaked corn with supplementation of live yeast (Treatmet 2), respectively. The trial was lasted for a total of 8 weeks. The results showed that milk yield and protein percentage of Treatmet 2 were significantly higher than those of Control (P＜0.05), and also numerically higher than those of Treatment 1 (P>0.05). Milk protein content of Treatment 2 was increased substantially compared with Control (P＜0.05), and milk yield was improved as well. Treatment 2 had higher content of blood cholesterol and low-density lipoprotein cholesterol than Treatment 1 (P<0.05) , but had lower concentration of blood insulin than Control (P<0.05) and Treatment 1. Treatment 2 also had lower values of abnormal blood cells, hemoglobin content and packed cell volume than treatment 1, and lower than Control (P<0.05) as well. In general, corn steam-flaking and such treatment combined with supplementation with live yeast can improve lactating performance and milk quality obviously. The reason for this improvement may be associated with the enhanced energy metabolism, improved blood parameters and immunity of cows fed a steam-flaked corn diet and supplemented with live yeast.Keywords：lactating cow;corn steam-flaking;live yeast;lactating performance;blood parameter1|1|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：The purpose of this study was to reveal the phylogenetic diversity of ureolytic bacterium from dairy rumen microbial by PCR using urease conserved ureC degenerate primer and bacterial 16S rDNA universal primer and sequencing. All of the previously identified plasmids for the sixteen urease positive clones which were identified previously were exacted. Polymerase chain reaction degenerate primers based on the ureC gene which was conserved in ureolytic bacterium were designed and used to amplify the ureC genes from the extracted plasmids. The universal 16S bacterial primers were used to amplify the 16S rDNA gene of positive clones. PCR products were purified and ligated to pMD19-T vector. Transformants got by transforming ligation product into E.coli JM109 were sequenced. The sequences were analyzed by Blast on GenBank and RDP, and the phylogenetic trees were built by Mega 4.0. In results, four clones (U1, U5, U13 and U15) containing ureC genes were obtained. The phylogenetic tree of ureC revealed that all four clones were clustered into several bacterial phylums. U1, U5, U13 and U15 belonged to Firmicutes, ε-Proteobacteria, β-Proteobacteria and Actinobacteria, respectively. U1, U3 , U7, U10, U11, U12 and U14 which contained the 16S rDNA sequence had the most identity to Staphylococcus,Shigella,Bacillus,Acinetobacter,Achromobacter,uncultured bacterium and Bacillale. The diversity of ureC and 16S rDNA revealed the diversity of ureolytic bacterial in dairy rumen.Keywords：urease;ureolytic bacterium;diversity;metagenome;16S rDNA;ure;C2|2|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to explore the function of the PmpD gene in preventing and diagnose of the avian, the N-domain of the PmpD gene was cloned by PCR method based on the whole gene sequence of the avian Chlamydophila psittaci CAL-10 strain. Specific target gene was cloned into the PBS-TII vector and identified by the sequence analysis. The target gene and deduced peptide sequence were compared to the N-domain gene sequence of the characterized C.psittaci 6BC strain. They were found to be 99% identical to the N-domain gene sequence that of C.psittaci 6BC strain.Compared to other C.abortus strain the similarity of the gene sequence and peptide arranged form 77% to 89%. Approximately 63 ku recombinant fusion protein was expressed after the N-domain was subcloned into pET-32a vector, the recombinant vector was transformed into the host bacteria BL21(DE3)and the recombinant fusion protein,63 kD,was highly expressed after induction with IPTG. The recombinant protein could react specifically with polyclonal antibody of C.psittaci by Western-blot analysis,but it could not react with polyclonal antibody originated form swine C.abortus and sheep C.abortus.The results showed that the PmpD have species-specificity.In conclusion,the N-domain was successfully cloned and expressed in prokaryotic vector,the current study might play a key role in exploring the fundamental biological function.Keywords：PmpD;gene;N-domain;clone;expression;recombinant protein;Chlamydophila psittaci0|1|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to investigate the effects of Astragalus polysaccharide (APS) on microvessels and mast cells, the experiment was based on the model of rat sensitized by subcutaneous injection of ovalbulmin (OVA), adopted CD34 immunochemistry method and toluidine blue staining to investigate the effects of APS on microvessels and mast cells in rat skin. After the stimulation of OVA, the densities of CD34+ microvessels and mast cells were significantly increased from 33.6 and 77.2 cells/mm2 to 67.2 and 180.0 cells/mm2, respectively, and the mast cell degranulation occurred around the microvessels. The APS powder injection significantly downregulated the density increase of CD34+ microvessels and mast cells to 39.7 and 99.7 cells/mm2 induced by OVA in rat skin, and decreased the degranulation of mast cells. It is one mechanism of anti-Inflammatory effect of APS that it downregulates the expression of CD34 in microvascular endothelial cells and the increase and degranulation of mast cells around microvessels, which maybe contribute to the adherence reducing between inflammatory cells and microvascular endothelial cells.Keywords：astragalus polysaccharide;mast cell;microvessel;degranuation1|1|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：The dynamic of combined forms of humus and humus components in different tillage practices that lasted for eight years were studied through a method combining field sampling and lab analysis. The results were as follows. The majority of combined humus in different tillage practices was tightly combined humus which represented more than 50% of total heavy fraction organic carbon. The loosely combined and stably combined humus increased with continuous conventional tillage (CTA) practice. But the content of tightly combined humus and its share in heavy fraction organic carbon decreased. It was evidenced that humus was preferred to degradation under CTA. The annual increasing rates of loosely combined and tightly combined humus in rotary tillage (RTS) were 0.08 and 0.31 mg/g respectively. In addition, the stably combined humus of RTS was the highest one among all the tillage practices. RTS led to an acceleration of humus accumulation and renewal. The main cause of the acceleration of loosely combined humus accumulating in corresponding layer was the depth of tillage operation and the position of straw displaced by that. The humification degree of soil was enhanced by combination of straw returning and disturbance of tillage.Keywords：tillage practice;humus;combined forms;components1|1|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：Bioindication of nitrogen (N) deposition is concerned by environmental scientists, but few higher plants have been reported to indicate variations in atmospheric N deposition. Leaf total N concentration and δ15N value of a wide-spread herbaceous creeper Humulus scandens from the six sites in the North China Plain were investigated, together with the atmospheric reactive N concentrations at each site, to explore the impact of N deposition on H. scandens, and the possibility of H. scandens as a bioindictor of N deposition. The results showed that there was a strong correlation between leaf total N and atmospheric NH3-N, and a weak correlation between leaf total N and atmospheric NO2-N or total atmospheric reactive N. The tender leaves had higher N concentration and δ15N value, and showed a steeper slope of leaf total N and δ15N along the gradient of atmospheric NH3-N concentration, compared with the adult ones of H. scandens. Our study suggests that H. scandens might serve as a potential bioindicator of atmospheric NH3-N concentration and deposition with the N concentration and δ15N value in its tender leaves being analyzed, though further evidence is needed.Keywords：atmospheric reactive nitrogen;nitrogen deposition;bioindication;Humulus scandens;tender leaf;δ;15;N0|7|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：This paper analyzes the current status of the implementation of agro-ecological compensation policy in Beijing city based on the data from the practical investigation, and evaluates the policy execution through the use of game theory model. The results show that there are still some problems in the policy execution, such as the limited sources of funding, single payment pattern, the narrow scope of crop subsidies and the lack of science-based standards. Through the use of game theory model, it was found that when the farmers awake to the serving value of ecosystem as a form of income, they achieved dominant equilibrium outcome, that is, the farmers will grow cereal grains in winter if the compensation policy is implemented and the current standard of subsidies cannot meet the requirements of farmer’s pursuit of economic interests if farmers weakened the concept of ecological values, not be regarded as a kind of income. Combined with the conclusions of the model, some advices were proposed, including that the farmland ecological compensation policy should be further improved to strengthen farmers’ awareness to agro-ecosystem services and promote the expansion of scale operation of land.Keywords：ecological compensation;subsidy effects;game theory;subsidy policy;Beijing City1|1|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：In view of the problems of comprehensive evaluation traditional analysis of flue-cured tobacco varieties which was analyzed by the analysis of only one trait, as well as the qualitative description from other traits, the tobacco varieties in NanYang were tested and a comprehensive appraisal was made by grey situation decision making approach. The results indicated that when the weighted trait were considered, the order of pros and cons of flue-cured tobacco variety is yunyan87, yunyan85, zhongyan100, zhongyan98, k326, 9717, 8541, 39511, and zhongyan101.The analytical results are in accordance with practical ones. The decision law of the grey situation is a kind of comprehensive quantitative analytical method, which provides an approach for evaluating the new variety of the flue-cured tobacco, and can be used to resolve the incommensurability of multiple objectives and contradictions among them, and to compensate for the deficiency of the traditional analytical method.Keywords：gray situation decision making;flue-cured tobacco;variety;comprehensive appraisal0|1|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：This paper systematically reviews the history and present situation of agricultural rainfall harvesting practices in Beijing. Based on the actual operation in 2008, the efficiency, cost-benefit and up-scaling were analyzed for a greenhouse rainfall harvesting system. The results from water balance and cost-benefit analysis showed that the rainfall harvesting efficiency was up to 66% and the rainfall using rate reached to 69%. Furthermore, the ratio of benefit to cost was 1.54 in the case of governmental investment and 5.85 in the case of farmer investment, in which farmers used the facilities in multiple ways. However, the water price of agriculture directly influenced the application and up-scaling of the project. Farmers will not use the RWH system if the water price is lower than 2.2 RMB per m3. To solve the problems encountered during the implementation of agricultural rainfall harvesting system, a number of new measures about effective use of the system in a large scale are given in this paper.Keywords：Beijing;greenhouse agriculture;rainwater harvesting;cost-benefit1|1|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：In this paper, the research and application progress of the plant acoustic frequency technology are reviewed. The fundamental study of the technology has progressed from the levels of group, individual and organ to the cellular and molecular levels, including the research of photosynthetic and respiratory metabolism, cell cycle synchronization, growth hormone, several of enzymatic activities, soluble protein and RNA changes. However the technology is still in the early stages of industrialization. The experimental results on major crops i.e. rice, cotton, wheat and some vegetables verified effects that the technology can increase the crop yield, improve the nutrition and quality, strengthen the capability of disease and enhance environmental protection. Sound waves with specific frequency can increase crop yield. For example, the rice yield in pot experiment increased by 17.4%-39.7% and 5.7% in the field trials; cotton yield by 6.0%-9.0%; wheat yield by 17.0%; and the yields of cucumber and green pepper up to 60.0%. Sound processing can increase the quality of crops, for instance, head rice rate and protein content of rice increased by 59.4% and 8.9%, respectively; starch, protein and fat content of wheat increased by 6.3%, 8.5% and 11.6%, respectively. Application of this technology can effectively militate against plant diseases and insect pests. For example, the sheath blight of rice reduced by half; and the spider mite, aphids, gray mold, late blight and virus disease of tomato in the greenhouse decreased by 6.0%, 8.0%, 9.0%, 11.0% and 8.0%, respectively. In addition, the three-year rice test results show that the application of sound processing can reduce the amount of 25.0% fertilizer. The input-output ratio of the application of sound control technology on the rice, cotton and some vegetables is 1∶2-1∶3 generally. The technology has a great marketing potential. For example, if the products have been sold to the specialized farmers, say, each village purchase 3- 4 sets. As the result, there will be one million sets being sold in China each year. The processed farming area can reach to 6.7×106 hm2. Comparing to domestic market, the international market is even bigger. The trend of applied research of audio plant control technology is, on the one hand, combined with information technology; on the other hand is combined with technologies of electricity, magnetism, light, heat and nuclear engineering into an integrated technology system.Keywords：physical agriculture;acoustic frequency technology;rice;cotton;wheat;vegetable2|1|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：In this thesis, changes of growing and fluorescence parameters of strawberry by application of sound frequency treatment were explored. The results showed that the number of the flowers, the fruits, as well as the content of chlorophyll were increased after 35 days of sound frequency treatment. The maximal fluorescence(Fm), photochemical efficiency of PSⅡ(Fv/Fm),non-photochemical quenching(NPQ) increased markedly under sound frequency treatment after 35 days, while change of the initial fluorescence (F0), photochemical quenching (qP) were not prominent. These results suggested that acoustic frequency treatment could improve the activity of PSⅡ reaction centers, enhance the electron transport and the photochemical efficiency of PSⅡ.Keywords：sound frequency treatment;strawberry;photosystemⅡ;chlorophyll fluorescence;plant characters0|1|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
- Abstract：The study object was precision metering device with sucker and the pressure field of vacuum seed-metering components was simulated under the different nozzle diameters of the sucker and the vacuum-pressures from different gas sources and the chamber shapes by CFD technique. The simulation results were verified by the experiments and showed that the larger pickup hole diameter could improve the vacuum ability, but it might cause an uneven pressure distribution in chamber and weakened the performance of seeds picking-up; however, the higher vacuum-pressure could enhance vacuum performance and the distribution of the chamber pressure had not affected. The chamber shape had no any influence on vacuum performance and pressure distribution in chamber. The results from simulation and experiments are consistent. When the pickup hole of sucker is 2 mm in diameter and the pickup vacuum is between 6.7-15 kPa, the picking performance of the self-made rice sucker precision metering device is well.Keywords：sucker;precision metering device;vacuum seed-metering components;CFD1|1|0<HTML><DownloadPDF> <Meta-XML>Updated：2023-12-22
