2017, 36(3):1-6.
Abstract:The typical farmland soil of Wuxue in Hubei Province was collected.Based on the phospholipid fatty acid (PLFA) extraction method existed,we set different methanol extraction time,soil sample weight and hexane dissolved volume.The results showed that the phospholipid fatty acids were extracted from the start of the methanol elution.The optimal weight of the soil in Wuxue typical farmland system was 2.0 g.The phospholipid fatty acid methyl esters dissolved in 250 μL hexane were proved to provide the most complete result.The further analysis of the microbial community structure in soils of different crops in Wuxue were conducted to verify the effect of the adjusted PLFA extraction method.The result showed that this method was of good stability and repeatability,reflecting the diversity of soil microbial community structure in typical farmland of Wuxue.
2017, 36(3):7-12.
Abstract:Three methods of BIOLOG microplate analysis with BIOLOG ECO Plate were applied and compared to explore the optimal way to analyze the carbon metabolism of farmland soils with carbon abundance. The soil samples were collected from Jingzhou Municipality and Huanggang Municipality,Hubei,China. The 100-fold eluted supernatant was incubated after incubating on ice. The 1 000-fold eluted suspension was incubated after incubating on ice. The supernatant was centrifuged after removing carbon. Color development of each well with optical density at 595 nm and 750 nm every 12 h was recorded with an ELISA Reader. The microbial activity in each microplate was expressed as average well color development (AWCD). We found that incubating 100-fold eluted supernatant could not accurately reflect the microorganism activities due to the available carbon in the supernatant which caused the reaction in the control well. The other two methods can clean up the carbon. The standard of AWCD of the method of incubating 1 000-fold eluted suspension after incubating on ice was significantly higher than that of incubating the supernatant after removing carbon with centrifuging,indicating that the latter one was more stably to detect the carbon metabolism of farmland soils.
2017, 36(3):13-18.
Abstract:The adsorption of extracellular DNA (a designed plasmid, pHTG) on the soil active particles and the influences of the minerals on the natural transformation of Bacillus subtilis were investigated with chemical adsorption and trace DNA detection analysis. The trace DNA was mixed with the three clay mineral solutions to clarify the adsorption characteristic of pHTG on permanent-charge soil active particles. The results showed that the adsorption of pHTG were dependent on the minerals. Different minerals had different adsorption. The maximum amount of pHTG adsorbed was in the order of goethite>kaolinite>montmorillonite. Minerals reduced the natural transformation. The transformation efficiency was decreased with the increase of mineral concentration. When mineral concentration increased from 0.0 mg/mL to 8.0 mg/mL, the transformation efficiency was reduced in two orders of magnitude. Montmorillonite significantly decreased the transformation, while goethite had the least influence.
2017, 36(3):19-24.
Abstract:In the previous study,a biological control strain Bacillus subtilis BS5 with a strong antagonism effect against several phytopathogens was isolated. A low temperature biocontrol strain named BS303 was obtained by inducing strain BS5 with UV. The activity of biological control of BS303 was investigated with plate confrontation essay and greenhouse plant pot. Results showed that the antagonism activity of BS303 against four pathogenic fungi at 20℃ was stronger than that of BS5. The protect index of BS303 and BS5 against Fusarium oxysporum f. sp. melonis at 28℃ was 0.701,and 0.667, with no significant difference between them. However,the protect index of BS303 (0.767) against Fusarium oxysporum f. sp. melonis at 20 ℃ was higher than that of BS5 (0.557).Spread plate and RT-PCR were used to determine the colonization dynamics of biological control bacteria and phytopathogen fungi in soil. The results showed that both biological control strains fitted and established well in soil. The colonization dynamics of BS303 strain was better than that of BS5 (wild type). Number of the phytopathogen fungi was significantly decreased when the biological control bacteria were applied.
2017, 36(3):25-31.
Abstract:To study the function of rice pectin methyltransferase OsTSD2 genes and its effects on growth and development,a dwarf mutant was found by screening the mutants and experimentally verified. The T-DNA was inserted in the seventh intron of the gene OsTSD2. This mutant was named as tsd2a (tumorous shoot development 2a). Other two allelic mutants tsd2b and tsd2c were found as well. Three allelic mutants had lower seed setting percentage,shorter grain length,narrowed grain width and reduced 1 000-grain weight. The glume of mutant had darkened colors,aggravating the degree of rupture,new and seriously broken backside. Results of fluorescence immunoassay indicated that the declined germination rate of mutant seed was due to lower methylation pectin in scutellum of germinating mutant seeds. Defective function of pectin methyltransferase OsTSD2 gene may obviously make the defective development and germination of the rice seeds.
2017, 36(3):32-37.
Abstract:To identify the differences among physiological races of Fusarium oxysporum f. sp. cubense (Foc),the cell wall-degrading enzymes,esterase isozyme and soluble protein of this pathogen were tested and analyzed. The results showed that four kinds of cell wall-degrading enzymes including polygalacturonase (PG),pectin methyl-galacturonase (PMG),celluloses (Cx) and filter paper enzyme (FPA) were detected in all the four physiological races of Foc from domestic and abroad. The PG and Cx activities of Foc 4 were the highest. The Cx activities of Foc 1 and Foc 4 from abroad were higher than those of the same race from domestic. The FPA activity of Foc 1 from domestic was the lowest,while there was no significant difference among other races. The PG activity showed no significant difference in the same race from domestic and abroad. The electrophoretograms of esterase isozyme and soluble protein indicted that great difference existed among all the four races. Cluster analysis further demonstrated that the isolates with similar pathogenicity were clustered into the same branch,which had close genetic relationship.
马婷婷 , 黄粤 , 皮婷 , 姚家成 , 冯喆 , 李晓华
2017, 36(3):38-43.
Abstract:A bacterial strain with antifungal activity against seven crop pathogenic fungi was isolated from soil and named as IIR21.The IIR21 strain was detected through agar block method and the results indicated that the IIR21 strain exhibited much stronger antifungal activity against Magnaporthe grisea,Rhizoctonia solani,Botrytis cinerea,Fusarium aminearum and Fusarium culmorum.The IIR21 strain was identified as Streptomyces through physiological and biochemical characteristics and alignment analysis of the 16S rRNA gene sequence.The fermentation broth of the IIR21 strain was separated and purificated by extraction,silica gel column chromatography and preparative high performance liquid chromatography,and a compound with a purity of 90.34% with activity against the Magnaporthe grisea 168 strain was obtained.The Streptomyces sp. IIR21 genome was sequenced using high throughput sequencing technology,and analyzed by bioinformatics tools.The result suggested that the IIR21 strain contained the gene cluster of clavams,and the metabolic pathway for clavam biosynthesis was proposed.
崔江宽 , 黄文坤 , 彭焕 , 孔令安 , 李惠霞 , 彭德良
2017, 36(3):44-50.
Abstract:To get a nematicide to effectively control the cereal cyst nematodes,Heterodera avenae,two new seed coating nematicides (Methylene (bis) thiocyanate),GannongⅠand Gannong Ⅲ,and four nematicide compounds,GannongⅠcombined with 60% Imidacloprid (0.5∶0.5),GannongⅠcombined with 25% Triticonazole (0.5∶0.5),Gannong Ⅲ combined with 60% Imidacloprid (0.5∶0.5),Gannong Ⅲ combined with 25% Triticonazole (0.5∶0.5) were tested on controlling the cereal cyst nematode H. avenae in Henan Province.Wheat seeds were treated with the six seed-coatings before sowing.The number of cysts were counted at three different wheat growing stages,and eggs in nematode and wheat yield were investigated at harvesting time.The results indicated that the number of eggs from cyst and cysts in soil with different nematicide treatments were clearly reduced after seed coating.Gannong Ⅲ and Gannong Ⅲ combined with 25% Triticonazole (0.5∶0.5) reduced the eggs for 37.59% and 32.86% and increased the yield for 16.09% and 26.40%,respectively.Gannong Ⅲ combined with 25% Triticonazole (0.5∶0.5) and Gannong Ⅲ restrained the female as 72.27% and 70.29%,and the cysts as 50.74% and 51.61%,respectively.The data demonstrated that Gannong Ⅲ combined with 25% Triticonazole (0.5∶0.5) and Gannong Ⅲ combined with 60% Imidacloprid (0.5∶0.5) controlled the cereal cyst nematode effectively and increased the yield of wheat,with a theoretical rate of 40.35% and 44.39%,respectively.Gannong Ⅲ combined with 25% Triticonazole (0.5∶0.5) was suitable to apply widely to control the cereal cyst nematode under natural field conditions.
2017, 36(3):51-56.
Abstract:To investigate the impact of biochar on Prunus pseudocerasu soil microbial and nutrients property,one of the P. pseudocerasu varieties ‘Manaohong’ cultivated in Guizhou was used as materials,aiming at improve the production and quality of the P. pseudocerasu and provide a theoretical basis for the application of biochar on fruit.Test was set up with the three different biochar application rates,including 0 (CK),5 (C1) and 10 kg (C2) pet plant were applied in the protected field.Results showed that at the initial blossoming stage,C1 treatment could effectively increase the quantity of bacteria,denitrifying bacteria and C2 increase the quantity of azotobacter significantly; in the full-bloom stage,the treatment of C1 improved the quantity of denitrifying bacteria and the quantity of azotobacter,denitrifying bacteria were significantly increased under the C2 treatment.Meanwhile,the microbial diversity on soil with the treatment of C1 and C2 were significantly higher than CK; on the fruiting stage,the quantity of fungi was effectively increased under the C2 treatment; applying biochar increased the soil pH and the content of organic matter,but the impact on soil nutrients varied with the phenological period.Our research indicated that applying biochar on soil could increase the amount phenophase and diversity of microorganisms of P. pseudocerasu ‘Manaohong’, as well as soil nutrients,while the raising efficiency was close related to the growth status of plants.
杨祥开 , 成春燕 , 欧娜 , 周志鹏 , 韦星明 , 许黎明 , 周兴
2017, 36(3):57-62.
Abstract:The majority of carbohydrate impurities in the mixture of α-arbutin enzymatic synthesis reaction were removed with alcoholic fermentation.An activated carbon fiber column was used to enrich α-arbutin with water and different concentration ethanol elution.The final recrystallization with methanol-ethyl acetate mixed solvent was used to obtain α-arbutin crystal.The results showed that the 50% ethanol solution elution part had the highest concentration of α-arbutin.After concentrated by vacuum concentration,this part was recrystallized with methanol-ethyl acetate mixture.Some colorless,needle-like α-arbutin crystal was obtained.The purity of crystal was over 99% α-arbutin by HPLC analysis.The established method is useful for industry production with its simplicity,low cost and high purified product.It will provide reliable parameters for the massive industry production.
史蒲娟 , 翟瑞芳 , 常婷婷 , 彭辉 , 林承达 , 罗俊
2017, 36(3):63-68.
Abstract:The traditional phenotypic parameter measurement of rapeseed plant is often completed in manual way,which is time-consuming and destructive.Two rapeseed cultivars with different growth form including Zhongshuang 6 and Huayouza 62 were used to be measured with the monocular vision and laser scanning technology.3D models of the rapeseed plants were generated.Four phenotypic parameters were measured based on the 3D models generated.The results showed that it was actually demonstrated the holistic morphological characteristics of plant from the reconstructed results with different methods.The cultivar Zhongshuang 6 is relatively simple and much better.Compared with the reference value,the average errors of phenotypic parameter measure in the reconstruction model were within 2.00%.The cultivar Huayouza 62 is more intricate with the average errors of within 3.00%.It was concluded that the results of the phenotypic parameter measurements under the two reconstruction methods errors were minor compared with the reference value,which can meet the practical requirements of agricultural production.It will provide data support for practical production.
刘泽文 , 田永祥 , 袁芳艳 , 刘威 , 周丹娜 , 杨克礼
2017, 36(3):69-73.
Abstract:To develop a rapid differentiation and quantitative method for detecting the pili antigen of E. coli K88,K99 and 987P strain,positive serum of rabbit was prepared with purified E. coli K88,K99 and 987P pili antigen and their AGP titers were 1∶32,1∶32 and 1∶128,respectively. Through sensitizing the Aldehydated sheep erythrocyte with the positive serum IgG,the optimal IgG concentrations in K88,K99 and 987P positive sera were determined at 40 μg/mL,160 μg/mL and 80 μg/mL,respectively. The same batch of K88,K99 and 987P pili antigens were detected three times using the same method and the RIHA titer of K88,K99 and 987P samples were 1∶1 600,1∶1 600 and 1∶800,respectively. The results showed that the detecting method had good specificity and reproducibility and could be used for differentiation and quantitative detection of pili antigen of E. coli K88,K99 and 987P strain.
2017, 36(3):74-78.
Abstract:The cDNA-SRAP technique was applied to analyze the difference of gene expression in the mucus between female and male ricefield eel and to screen sex-related molecular markers.Twelve polymorphic markers selected from 64 pairs of primer were used for cDNA-SRAP amplification and 123 polymorphic loci and 4 sex-special fragments were obtained.After gel extraction,cloning and sequencing,4 sex-special sequences were obtained and submitted to db GSS (data of genome sequence survey).The result of blast analysis showed that only one sequence hit the Lipotes vexillifer sulfate/thiosulfate import ATP-binding protein CysA-like,which was used to design one pair of primer for semi-quantitative RT-PCR.PCR product was amplified in mucus of both female and male ricefield eel.However,there was a significant difference in their expression levels,with the expression in male significantly higher than in female,which may due to the difference of skin cells and mucous gland cells between female and male.
2017, 36(3):79-85.
Abstract:The full-length coding sequence of the nueleoprotein (N) gene in spring virema of carp virus(SVCV) was amplified by PCR method using N-RFP plasmid as the template. The PCR production was cloned into the prokaryotic expression vector pGEX-KG. The fusion protein SVCV-N-KG was analyzed by SDS-PAGE. The BALB/c mice was immuned by purified SVCV-N-KG protein and the serum titer was determined by ELISA. One monoclonal antibody (McAb N-2) against N protein were generated and selected by ELISA and chromosome number analysis after four times of subcloning selection. McAb N-2 was characterized by IFA (indirect immunofluorescent assay) and Western blot assay. Further analysis showed that McAb N-2 targeted the 227-336 amino acid region of N protein. This study laid a foundation for the study of pathological mechanisms and clinical diagnosis of SVCV.
吴伟斌 , 游展辉 , 洪添胜 , 王玉兴 , 王海林 , 余耀烽 , 冯灼峰
2017, 36(3):86-92.
Abstract:To study the wheel vehicle in moutain orchard and improve the stability of the transport operation,the power control of a target system was constructed and tested.A control system hardware was built in accordance with independent power control strategy and control combined transport physical structure.After completing the system hardware,no-load test without system control and load test under the control system dynamic stability control was conducted.Results showed that the engine output power increases and offsetting the non-pit part of the wheel rolling resistance when the throttle opening increases.In the same driving resistance conditions,with the greater the throttle opening,the greater the wheel speed.At last,the absolute error range of the steady state wheel speed was between 0.178 1 km/h and 0.396 1 km/h with the relative error range of 0.71% to 5.27%.The experimental results show that the power wheel speed control achieves the target setting.After one pit in the power wheel of the transport vehicle,the speed of power wheel without pits can be adjusted to increase the power,which helps the truck to walk or trap in the muddy road.Of the situation there is enough power to climb out.
2017, 36(3):93-100.
Abstract:Simplified geometric model of the wheeled tractor- seat suspension system was constructed based on the software of Pro/E.The geometric model was then imported into ADAMS.The documentations of the tire property and road excitation were edited in ADAMS.The virtual prototype of tractor-seat-road system was established.The ride comfort of the tractor under different driving speeds and road excitations was simulated to explore the effects of speed and road excitation on the tractor riding comfort.The results show that the vehicle speed and road unevenness have huge impact on the ride comfort of tractor.The vertical vibration intensity of driver under the high driving speed is significantly higher than that under the lower driving speed.The subjective vibration sense of driver on the rough pavement is much stronger than that on the flat surface.The influence of the seat-suspension system on the riding performance was investigated.The results show that the seat-suspension system can significantly reduce the vibration amplitude of the vertical vibration and avoid the sensitive vibration frequency areas of the body’s internal organs and spine system.The riding performance was improved as well.
2017, 36(3):101-106.
Abstract:A model rotary knife roller based on similitude method was designed with 1/2 real size to study the performance of the double spiral rotary tillage and stubble-mulch roller machine while it till in paddy soil. A test platform of 1/2 size model roller for torque based on LabVIEW was designed. The indoor soil bin test of the 1/2 size model roller was conducted and its working torque was chosen as evaluation indicator while moisture content of soil, forward speed, rolling speed and tilling depth were selected as influential factors. The results of single factor tests showed that torque increased with the increase of forward speed and tilling depth, and decreased with the increase of knife rolling speed in experiment range. The result of L18(37) orthogonal test showed that the influencing sequence on the knife roller torque from significant to common was soil moisture content, tilling depth, forward speed of the test platform and knife rolling speed. Soil moisture content, tilling depth and forward speed of the test platform affected significantly, while knife-rolling speed did not. It will provide a reference for the optimizing structure parameters, motion parameters and power choice of double spiral rotary tillage and stubble-mulch roller.
2017, 36(3):107-112.
Abstract:A three-dimensional model of 2-DOF vibration screen was established and the working principle of this vibration screen was analyzed.The model was simplified and the motion parameters were analyzed through analyzing the displacement,velocity,acceleration and the force to improve the efficiency of the screen.The rationality of the design of 2-DOF vibration screen was confirmed.A model of 1-DOF vibration screen and 2-DOF vibration screen were established with ADAMS simulation software to verify how the output freedom affects the movement of the screen.The curves of screen surface inclination,horizontal displacement and acceleration,vertical displacement and acceleration from two different screens were obtained through simulation analysis.The horizontal acceleration of 2-DOF vibration screen was larger than that of 1-DOF.The vertical acceleration of 2-DOF vibration screen was less than that of 1-DOF.It is indicated that this design requirements is reasonable.It will provide a reference for optimizing the vibration screen.
2017, 36(3):113-118.
Abstract:A transition device was developed to solve the low efficiency,high breakage rate and low space utilization of domestic egg weight classification machine. It can transform the egg transport form from six row to single row and turn the eggs over with turning the long axis from horizontal to vertical to pack more quickly. Based on the three-dimensional model built,the kinematics of dynamic part and operative part were analyzed. The dynamic part is made up of a inscribed double eccentric sprocket structure. The solving equations of master-slave sprocket were listed between angular displacement and drive ratio,and the precise relationship of matching position between the operative and the power part was found out.
龚永杰 , 黎煊 , 高云 , 雷明刚 , 刘望宏 , 杨专
2017, 36(3):119-124.
Abstract:Respiratory tract diseases,frequently outbreaking in pig barns,bring economy lost in modern pig production.In this paper,a method was proposed to predict and monitor respiratory tract diseases by recognition of the cough sound of pigs.The sounds of pig were processed by the spectral subtraction denoising and the endpoint detection before being made into the improved Mel-frequency cepstral coefficients (MFCC),which are feature vectors input into the vector quantization matching algorithm (VQ algorithm).Thus a pig cough recognition model based on the VQ algorithm was developed to recognize the sound of cough.The results showed that the recognition rate,the false positive rate and the comprehensive recognition rate of the model based on the improved MFCC were 91%,12% and 90.0%,respectively,which were better than 88%,14% and 87.3% of the standard MFCC,suggesting the feasibility of the early warning of the respiratory tract disease of pigs in the future.
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