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          2020,39(4):1-6                                                                                                                
          Abstract:
          178 recombinant inbred lines (F12) of crossing rice varieties Gang 46B with A232 were used to investigate the length,width and aspect ratio of flag leaves in Lingshui,Hainan province and Wuhan,Hubei Province. 14 QTLs in total including 5 flag leaf width QTLs,6 flag leaf length QTLs,and 3 flag leaf lengthto width ratio QTLs were detected,which were distributed on rice chromosomes 1,2,4,6,7,10 and 12. LOD values were ranged from 2.52 to 5.62. The contribution rate of a single QTL to phenotypic variation varied from 5.56% to 21.27%.
          2020,39(4):7-14                                                                                                                
          Abstract:
          The pot experiment was used to study the effects of salt stress on growth of Oceanrice 86 and absorption,transportation and distribution of mineral elements using Huanghuazhan as control. The results showed that salt stress inhibited the dry matter accumulation of rice plants. The salt tolerance threshold of Oceanrice 86 and Huanghuazhan was 8.72 g/kg and 6.35 g/kg,repectively. Compared with Huanghuazhan,salt tolerance of Oceanrice 86 was stronger. Under salt stress,Oceanrice 86 selectively absorbed Na + through the root system and regulated the distribution of Na+ at the organ level. Its leaf sheath accumulated more Na +,reducing the toxicity of Na+ to the leaves. The content of K + in Huanghuazhan leaves did not change significantly from that of the control,but the K + content in the leaf sheath and root system was 4.64 g/kg in the soil. The K+ content was greatly reduced by 53.8% and 70.0%,respectively. The K+ content in various organs of Oceanrice 86 gradually decreased with the increase of the degree of salt stress,and the decrease of K+ content in leaves was relatively low. The content of Ca2+ and Mg2+ in the leaf sheath of Huanghuazhan decreased significantly with the increase of salt stress,while Oceanrice 86 had no significant changes. Compared with Huanghuazhan,Oceanrice 86 had a strong ability to inhibit Na + and promote the upward transport of Ca2 + and Mg2 +.
          2020,39(4):15-21                                                                                                                
          Abstract:
          A surface enhanced Raman spectroscopy (SERS) technique based on functionalized Au@Ag nanorods (Au@Ag NRs) was established to quantitatively detect Hg2+ in aqueous solutions.In the presence of Hg2+,its coordination with 2,5 dimercapto 1,3,4-thiadiazole (DMCT) on the surface of Au@AgNRs caused the aggregation of SERS detection probes,resulting in a “hot spot” effect,leading to the SERS signal of DMCT increased at 1 360 cm-1.The increased SERS signal showed a good linear relationship with Hg2+ in the concentration range from 0.1 to 10 μg/L :Y=195.49384X+1676.23663(R2=0.991).The detection limit was as low as 17 ng/L,much lower than that of the Hg2+ content(1 μg/L) in drinking water specified by World Health Organization(WHO).The results of spiked recovery test carried out in the actual water sample showed that the spiked recoveries of Hg2+ were from 100.1% to 106.5%,and the relative standard deviations were from 1.23% to 7.99%.The Hg2+ sensing detection technique with accuracy,rapidity and high sensitivity based on SERS has an effective application for quantitatively detecting Hg2+ in real water.
          2020,39(4):22-28                                                                                                                
          Abstract:
          “Hot Green No. 2” pakchoi was pot-planted with five treatments including 0% C,1% C,2% C,4% C and normal application of potassium fertilizer to investigate the effects of biochar application on potassium content of different forms in red soil and the growth of pakchoi. Results showed that the effects of biochar on content of water-soluble potassium,exchangeable potassium and non-exchangeable potassium in red soil were increased by 12.6%-51.8%,13.3%-43.5% and 10.3%-26.1%,respectively,compared to the control. The effect of biochar on improving different forms of potassium between 4% C and normal potassium was the most similar. Biochar application increased soil pH value significantly by 0.06-0.25 units,as available phosphorus,available potassium and organic carbon in soil. Also the cation exchange capacity,exchangeable calcium and magnesium content increased significantly,while the exchangeable aluminum content decreased significantly with a decrease of 87%-98%. Biochar application could improve pakchoi growth performance as increasing the biomass,leaf number,plant height and fresh weight of pakchoi.
          2020,39(4):29-37                                                                                                                
          Abstract:
          This study investigated symbiotic function of purple acid phosphatase gene MtPAP3 in Medicago truncatula with MtPAP3Pro∶∶GUS histochemical location,over-expression and CRISPR/Cas9 gene knock-out. The results showed that MtPAP3 was mainly located in vascular bundle of roots and nodules,and meristem and infection zone of nodules. The transcription levels of MtPAP3 were enhanced in roots and nodules under Pi deficiency conditions. The numbers and nitrogenase activity of nodules were increased in transgenic overexpression plants. The knock-out of MtPAP3 significantly inhibited the development and nitrogenase activity of nodules. It is indicated that MtPAP3 involves in phosphorus metabolism and symbiotic nitrogen fixation in nodules under low phosphorus stress.
          2020,39(4):38-45                                                                                                                
          Abstract:
          Two phosphate solubilizing bacterial strains,PSB-1 and HZP1,were isolated form soybean nodules and rhizosphere soil. The ability of these two strains to produce IAA (indole-3-acetic acid IAA) and the ability to dissolve inorganic phosphorus were measured by Salkowski colorimetry and molybdenum antimony-phosphonium colorimetry. Soybean and Astragalus sinensis were co-inoculated. Results showed that both two phosphate solubilizing strain produced IAA. The legume growth-promoting effects of the phosphate solubilizing strains and rhizobium inoculum were investigated in unsterilized soil and soybean planting field. Inoculation with HZP1 or PSB-1 promoted the growth of Astragalus sinensis and soybean. Co-inoculation of phosphorus-solubilizing strains with rhizobium further increased the shoot biomass,fresh weight of nodules and the number of nodules of soybean and Astragalus sinensis. The results of field tests showed that inoculation with rhizobium or phosphate dissolving agents alone had a certain effect of increasing yield but double inoculation with rhizobium and phosphate dissolving bacteria did not increase the yield significantly.
          2020,39(4):46-56                                                                                                                
          Abstract:
          The dynamic changes of plant community structures at different restoration stages in the aerial-seeding region in Otindag Sandy Land were studied,aiming to understand the restoration characteristics and change rules of vegetation restoration. From 2013 to 2017,vegetation survey tests were conducted in 11 aerial seeding areas in the Otindag Sandy Land. Correspondence analysis,correlation analysis,and Mann-Kendall trend analysis were used to analyze stages of vegetation restoration in the aerial seeding area and to discuss the status and role of each functional plant in the community based on a functional perspective. The results showed that it was divided into three recovery stages across 19 years. Moreover,after aerial seeding,the degree of dependence among the following seven functional plants of rubs/subshrubs,perennial weeds,annual/biennial weeds,perennial leguminous forage,perennial gramineous forage and annual/biennial gramineous forage,was decreased gradually.Community stability was increased by the number of recovery years. Dominant function type of vegetation restoration was not consistent in different restoration stages,resulting in timing management could be employed at different stages. Consequently,the succession stage and overall development trend of plant community are more conducive to the recovery and reconstruction of the vegetations in degraded sandy land.
          2020,39(4):57-62                                                                                                                
          Abstract:
          Based on the tourist statistics data of the Taizishan Forest Park,the paper used the composition method of ecological footprint to calculate the tourism ecological footprint,tourism ecological carrying capacity and tourism sustainable development of the forest park. The results show that: the total tourist ecological footprint of the Taizishan National Forest Park in 2018 was 1 013.36 hm2,the total tourism ecological carrying capacity was 10 738.99 hm2,the total tourism ecological surplus was 9 725.63 hm2,the degree of tourism sustainable development was 0.09,which reflected that the tourism of the Taizishan National Forest Park is in an ideal state of ecological surplus and sustainable development. 
          2020,39(4):63-68                                                                                                                
          Abstract:
          Currently,litter size trait is an important indicator to measure sow fertility and play important roles in determining total income of pig farm in China. An accurate prediction of these traits in the early life of an animal will allow pig producers to adjust their management practices in order to cull bad sows early and improve the reproductive ability of core sows. However,there are many factors not only influence sow’s litter size trait,but also influence each other. Traditional prediction methods may not be powerful enough to capture complex interactions while avoiding overfitting. In this case,learning algorithms that can learn from current data to predict the animal’s future performance offers promise. In this study,firstly,the sow’s production data,including total number of piglets born (TNB),number born alive (NBA),number of healthy piglets(NHP),number of piglets aged 5 day (N5D) and number of piglets weight above 1 kg (NPWA1) were processed and described statistically. Then,the R-package Boruta was used to screen out important eigenvalues affecting the litter size traits of sows,such as breed,parity,mating season,delivery season,gestation period,interval birth and birth litter weight. Last,regression analysis was performed by traditional linear regression method and three different machine learning methods including decision tree (DT),K-nearest neighbor (KNN) and support vector machine (SVM). The evaluation index of model including R2 and MSE are obtained by ten flod cross validation. Additionally,modeling methods was assessed by these indexes and best model was screened scatter plot using a part of original data. The results showed that the R2 of all regression analysis methods in TNB,NBA,NHP,N5D NPWA1 was over 0.71 (0.71-0.88),which showed that the selection of characteristics is correct. The SVM model was not only significantly better than other machine learning methods (P<0.05),but also better than traditional regression method in predicting TNB,NBA,NHP,N5D and NPWA1. The SVM model of NPWA1 is the best in all models. Therefore,machine learning methods will become a new approach for pig producers to breed high-fecundity sows in the future.
          2020,39(4):69-76                                                                                                                
          Abstract:
          To investigate the expression of BMPR1A in various tissues during different physiological periods (follicular and luteal phases) and in ewes of different fecundity (monotocous and polytocous),and to analyze the association of its polymorphism with litter size in Small Tail Han (STH) sheep,qPCR was used to detect the expression of BMPR1A in 14 tissues in STH sheep,meanwhile,Sequenom MassARRAYSNP assay was applied to genotype three single nucleotide polymorphism sites (SNPs) of BMPR1A gene in different sheep breeds,and then the association between the BMPR1A polymorphism and litter size in STH sheep was analyzed. The results showed that the expression of BMPR1A in hypothalamus and ovary of polytocous ewes was higher than that of monotocous ewes,but did not reach a significant level (P>0.05). From genotyping,the genotype and allele frequencies of g.41128335A>T and g.41127600C>T loci of BMPR1A were significantly different (P<0.05) between polytocous and monotocous sheep breeds. The χ2 test indicated that the three SNPs were under Hardy-Weinberg equilibrium (P>0.05) in most of the sheep breeds. Association analysis showed that three loci of BMPR1A gene had no significant association with the litter size of different groups of STH sheep (P>0.05),and the litter size of mutation was higher than that of wild for g.41128335A>T and g.41127598A>G loci. Therefore,we concluded that there may be a certain positive correlation between the expression of BMPR1A gene and litter size in STH sheep,but the three SNPs had no significant association with the litter size of STH sheep,which indicated they may not be the key loci that affect the expression or function of BMPR1A. 
          2020,39(4):77-84                                                                                                                
          Abstract:
          Mycoplasma bovis is one of the serious pathogens causing bovine respiratory diseases. Meanwhile,M. bovis can cause a variety of clinical signs,including bronchopneumonia,mastitis,arthritis,genital tract inflammation,and tenosynovitis. Adhesion to airway epithelial cells is a key step for M. bovis colonization and invasion of cells. Adhesin is one of the main virulence factors of M. bovis. Research about attachment has become an important field of pathogenic mechanisms research of M. bovis. To further analyze the adhesion characteristics of the M. bovis VspX protein,experiments,including indirect immunofluorescence assay,adhesion assay of protein and mutant strain to embryonic bovine lung (EBL) cells,antibody inhibition adhesion detection,ELISA assay of protein and strains binding fibronectin (Fn),were carried out,to clarify the molecular mechanism of VspX protein adhesion. The results showed that the M. bovis VspX protein was located on the surface of the strain. The recombinant VspX protein (rVspX) was able to adhere to the embryonic bovine lung (EBL) cells. Compared with the M. bovis wild strain (M. bovis WT),the M. bovis VspX gene-deleted mutant strain (M. bovis ΔVspX) had a significantly decreased ability to adhere to EBL cells in vitro (P<0.05). The above results showed that the VspX protein was an adhesion-related protein. The anti-rVspX monoclonal antibody was able to inhibit the adhesion of M. bovis to EBL cells,which further confirmed the specificity of the adhesion. Also,the rVspX protein bound to Fn in a dose-dependent manner,and the M. bovis ΔVspX strain had a significantly lower adherence ability to Fn (P<0.05) than that of the M. bovis WT strain. These results further demonstrated the binding specificity of M. bovis VspX protein to Fn. And Fn was distributed on the surface of EBL cells. In summary,the study validated that M. bovis VspX protein was an adhesion-related protein with Fn binding properties,and the adhesion of VspX to EBL cells was mediated by the extracellular matrix component,Fn.
          2020,39(4):85-92                                                                                                                
          Abstract:
          Epidemic haemorrhagic disease virus (EHDV) is an arbovirus that seriously endangers ruminants. Currently,nine serotypes of EHDV have been discovered worldwide,and five of them are prevalent in China. Neutralization test is the gold standard for serotype identification of EHDV,which has the shortcomings of time-consuming,laborious and long experimental period. Therefore,establishing an accurate and rapid serotyping method for EHDV is of great significance for the prevention and control of this disease. In this study,the second gene segment (Seg-2),which determines the serotype of epizootic haemorrhagic disease virus (EHDV),was used as the target gene to establish a one-step RT-PCR method for serotype-specific detection of EHDV. The results of specificity test showed that the method could accurately identify different serotypes of EHDV,and had no cross-reaction with bluetongue virus,chuzan Virus and akabane virus. The results of sensitivity test showed that the detection limit of the EHDV nucleic acid for different serotypes could reach 102 copies. EHDV strains isolated from different times and different regions in China were identified by this one-step RT-PCR and the results showed that the 31 EHDV isolates belonged to five serotypes,inculding EHDV-1,-5,-6,-7 and -10. The results of the RT-PCR were completely consistent with the results of the serum neutralization test. The above results showed that the method established in this study had good specificity and high sensitivity,and could quickly and accurately identify the serotype of EHDV strains.
          2020,39(4):93-98                                                                                                                
          Abstract:
          After immunizing Bactrian camel with CRP as immunogen,the peripheral blood lymphocytes were isolated,the total RNA was extracted,and then the cDNA was obtained by reverse transcription. The target gene fragment was obtained by nested PCR and cloned on the arm of T7 vector of phage to construct the original phage library. After four rounds of biological panning,the phage library after panning was identified by Phage-ELISA. The recombinant plasmids of pET-28a and positive clones were constructed by BamH Ⅰ and HindⅢ double enzyme digestion and transformed into BL21 strain for low-temperature induction expression. The single domain antibody was purified by His-Ni affinity chromatography,and then the reactivity between the single domain antibody and CRP was identified by indirect ELISA. The results showed that the phage library with a capacity of 1.08×108 cfu was successfully constructed,and the gene insertion rate was 96.43% (27/28). Four positive clones were successfully constructed and expressed in BL21 cells. The molecular weight was about 22 ku. By ELISA,the four antibodies showed high affinity and specificity. The titer of V2 and V3 was 1∶3 200,which proved that the antibody could be applied to the development of practical detection methods.
          2020,39(4):99-104                                                                                                                
          Abstract:
          Recombinant expression vector of the Streptococcus agalactiae ATCC51487 gene was established by using PCR amplification,double digestion of EcoRⅠand XhoⅠ,and resistance screening,etc. Effects of induction temperature,concentration and time on the expression products were examined. The protein was purified by affinity chromatography and ion exchange chromatography,and the activity of SrtA was determined using energy transfer resonance. The results showed that after the srtAΔN82-pGEX- 6p - 1 vector was transformed into BL21 (DE3),a large amount of soluble protein were obtained by inducing at 1 mmol/L IPTG at 37℃ for 6 h. The purity of SrtA was higher than 85%. Moreover,the purified SrtA could significantly increase the fluorescence intensity when co-incubated with the substrate,indicating that the recombinant SrtA had good biological activity.
          2020,39(4):105-113                                                                                                                
          Abstract:
          With Penicillium digitatum DSM62840 as the object of research,the extraction conditions of related enzymes in the process of converting limonene to α-terpenol were optimized to obtain high activity. And limonene converting-enzyme was extracted by high pressure cell crushing method. Taking the limonene converting-enzyme activity as evaluation indicator,the response surface methodology was used to optimize the extraction technology based on single factor test. At the same time,the properties of limonene converting-enzyme were preliminarily studied. The results showed that the optimum conditions for extracting were as follows: disruption pressure of 100 MPa,crushing times of 6,and liquid-to material ratio of 15∶1 (mL/g). Under the conditions,the yield of α-terpenol was 855.75 mg/L,and the enzyme activity was 71.31 U. The optimum conversion time of limonene converting-enzyme was 4 h,and the highest enzyme activity was obtained in phosphate buffer. Limonene converting-enzyme might be cytochrome P450,and different metal ions have different effects on the enzyme: Fe2+ had slight inhibition on the enzyme,while Ca2+,Mg2+,Mn2+,Zn2+,Co2+,Ba2+,Na+,K+,Fe3+ and Ni2+ had different activation effects on the enzyme. SDS-PAGE analysis of the crude enzyme solution showed that the extraction effect could be better under the optimum conditions.
          2020,39(4):114-120                                                                                                                
          Abstract:
          The polypeptides were prepared from silver carp skin by the method of mixed enzymatic hydrolysis,and divided into SP1(>6 ku),SP2(3-6 ku) and SP3(<3 ku) by ultrafiltration. The antioxidant capacity in vitro of three polypeptides and the amino acid composition of SP1 and SP3 were analyzed. It was suggested that SP3 has the strongest antioxidant capacity in vitro. Subsequently,the antioxidant capacity in vivo of SP3 was measured. The results showed that the order of hydroxyl radical scavenging rate,superoxide anion radical scavenging rate and reducing ability in the three polypeptides was SP3>SP2>SP1,but there was no significant difference in chelating rate of copper ions. Analysis of amino acid composition showed that the percentage of hydrophobic amino acid in SP3 was significantly higher than SP1. Besides, compared with the injured group,SP3 group had higher indexes of liver and spleen. Furthermore,SP3 significantly increased the activities of SOD,GSH-Px and CAT and decreased the content of MDA in serum and liver. In conclusion,SP3 has better antioxidant activity than SP1 and SP2.
          2020,39(4):121-127                                                                                                                
          Abstract:
          Deep-frying is one of the traditional method of food processing with multiple advantages. However there are some safety hazard factors in deep-fired food which recently received many attentions. Advanced glycation end products (AGEs) is one of the main harmful compounds in deep-fried food which leads to human aging and insulin secretion defects. Nε-carboxymethyllysine (CML) and fluorescent AGEs are usually used as the marker of AGEs. Grass carp is the largest freshwater fish in China. A large number of grass carp is processed using deep-frying every year. Therefore it is necessary to study the level of CML and fluorescent AGEs in deep-fried grass carp and to find effective methods to reduce the content. The purpose of the study was to investigate the effects of frying time and batter on the content and distribution of AGEs in deep-fried fish nuggets and to develop processing method to reduce the safety concerns. In this study deep-fried fish nuggets (DFN) and breaded fish nuggets (BFN) were prepared using grass carp for 0,30,90,120,180,240 and 300 s. The AGEs content and physicochemical properties of the crust and internal of the fried fish were measured. The results showed that water loss oil absorption,Maillard reaction and oil oxidation mainly occurred on the fish crust during frying. Therefore the CML content in the fish crust of DFN and BFN was 5.6 and 6.4 times that of the interior,respectively. Extending frying time resulted in higher water loss and oil absorption in both the fish crust and interior while the malondialdehyde content firstly increased and then became stable. Extending frying time could also promote Maillard reaction in the fish crust and significantly increased the content of CML and fluorescent AGEs. Compared with DFN,the BFN crust had lower moisture content and higher fat content. The Maillard reaction and fluorescent AGEs content rapidly increased during the late frying period but the use of the batter prevented the protein from directly contacting the high-temperature oil and thus the CML and fluorescent AGEs content in BFN crust were significantly reduced by 34.6% and 20.8% compared with DFN at 300 s. The use of the batter also significantly reduced the CML content in the interior of fish but had no significant effect on the fluorescent AGEs content. In conclusion the use of the batter and reducing the frying time could reduce the AGEs content in the fish crust and interior.The study provided basic information for the development of the healthy aquatic food.
          2020,39(4):128-136                                                                                                                
          Abstract:
          To study the effects of micro-flowing water treatment on the crucian carp flesh quality,the main nutritional components,taste characteristics,odour characteristics,and volatile components of the pond-cultured crucian carp (Carassius auratus gibelio) flesh processed by the micro-flowing system were measured after different treatment durations (0-9 d).The results showed that the micro-flowing water treatment hardly influenced the moisture,crude protein and crude fat contents in cultured crucian carp flesh(P>0.05),whereas it had significant effects on the ash,muscle glycogen,total sugar content in fish flesh as well as on the taste,odour and sensory scores (P<0.05). With the extension of micro-flowing water treatment time,the glycogen and total sugar contents significantly decreased while the ash content significantly increased (P<0.05). According to the results of electronic tongue and electronic nose detection,the micro-flowing water treatment can significantly change the taste and odour characteristics of crucian carp flesh. As the micro-flowing water treatment time extended,the content of odour volatiles in the flesh of the crucian carp significantly decreased,and the representative flavor substance in the fish significantly increased. Meanwhile,the odour,taste,texture,and the sum scores of steamed fish were also greatly raised. The sensory score of the crucian carp flesh processed for 7 d was higher than that of samples processed for 0 d,1 d,3 d,and 5 d. However,there was no difference between the samples processed for 7 d and 9 d with micro-flowing water treatment. In summary,the short-time micro-flowing water treatment (≤7 d) hardly affected the crude protein and crude fat contents of crucian carp flesh,but it could remarkably improve the flesh quality of crucian carp with the most suitable treatment duration (7 d).
          2020,39(4):137-146                                                                                                                
          Abstract:
          Freezing is a common processing method used in the production of surimi. In order to prevent quality deterioration during freezing storage,commercial cryoprotectant (4% sucrose and 4% sorbitol) is added,which introduces excessive sweetness and calorie and limits partial consumers. With low sweetness,rich probiotic function and reasonable structure,inulin is a potential cryoprotectant. Therefore,it is essential to conduct a systematic research on the freezing resistance of inulin with different degree of polymerization for surimi. The purpose of the study was to investigate the effects of inulin with different degrees of polymerization on protein denaturation and quality deterioration of surimi,and to reveal the relationship between protein biochemical properties and gel properties. In this study,frozen silver carp surimi was prepared by adding short chain inulin (degree of polymerization 2-6),natural inulin (degree of polymerization 10-23) and long chain inulin (degree of polymerization 23-46). The protein biochemical and gel’s indicators were measured during frozen storage. Furthermore partial least squares regression analysis(PLSR) was performed to analyze the relationship between protein and gel’s indicators. Results showed that,all of the inulin had anti-freezing effect on surimi. Short chain inulin had the best effect among these,and could significantly inhibit the decrease of the salt-soluble protein content,Ca2+-ATPase activity,sulfhydryl content and the increase of surface hydrophobicity (P<0.05). Meanwhile,secondary structure,sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and gel properties (water holding capacity,gel strength and texture) of sample added with short chain inulin was the closest to those of fresh surimi. In addition,salt-soluble protein content,secondary structure,surface hydrophobicity and sulfhydryl content had sequentially decreased influence on gel qualities,which could be used as main indexes indirectly evaluating gel quality of frozen surimi. But Ca2+-ATPase activity exerted little influence. This study provided a reference for the freezing denaturation of surimi and the development of new cryoprotectant.
          2020,39(4):147-155                                                                                                                
          Abstract:
          Mechanized transplanting of rapeseed is an efficient planting mode. However,the complicated structure and instability of seedling detaching process affects the transplanting quality of rapeseed substrate seedling. An inclined detach device for rapeseed substrate seedling transplanter was developed to solve the problem that the seedling transplanting device of the traditional transplanting machine is easy to tip over during the transplanting of rapeseed. The structural composition and the seedling detach processes were analyzed. The key components were designed and the main structural parameters of the seedling detach device were determined. A mechanical model of seedlings in the transporting and separating stages of the seedling detach process was constructed to analyze the main factors affecting the stability of the seedlings. The results showed that the seedling block was stable during the transporting stage when the frictional characteristics of the seedlings were constant and the inclination angle of the belt was between 24.5° and 35.0°. The lager of the clamping force,the better of the separation effect in the separating stage. The optimized key parameters of the seedling detach device included 30° inclination angle of the belt,lager than 0.8 N clamping force(fj1),and 0.5-0.8 MPa air pressure of the cylinder(P). The results of bench experiment showed that the capsizes rate of seedlings block was 4.2% and the detaching rate was 92.5%,meeting the needs of seedling detaching of rapeseed substrate seedling. It will provide a reference for designing detach device of rapeseed substrate seedling transplanter
          2020,39(4):156-162                                                                                                                
          Abstract:
          A certain combine harvester cutting platform and grain allocation device was used to establish the geometric model based on Pro/E software and reasonably simplify by importing the model established into ADAMS. The virtual prototype model was obtained by adding constraints,loads and drives,and kinematics simulation was carried out on this basis. The range of the threshing device and other relevant parameters were obtained through the establishment of different drives and the simulation analyses of different working conditions of the threshing device. The results showed that only when the speed ratio was λ>1,the motion trajectory was cycloid,forming a closed buckle so that the spring teeth can push the crop stalk backwards. When the reel ratio of the reel is 1.55,it is closest to the best effect of the reel,which can meet the working requirements of normal work and avoid unnecessary falling loss. The maximum and minimum forward movement distances of the reel increase with the increase of pull-grain speed ratio. The forward movement range of the reel is 0.00-0.38 m.
          2020,39(4):163-168                                                                                                                
          Abstract:
          A kind of water chestnut (Eleocharis dulcis (Burm. f.) Trin. ) peeler using the combined cutting method of flat blade to remove top bud,inclined blade to remove bottom,and arc blade to remove lateral peel was designed to solve the problems of the irregular shape,large peeling loss and uncleanness of water chestnut. By measuring and modeling the shape parameters of water chestnut,the outer contour curve of water chestnut was fitted to determine the range of structural parameters of blades. Based on 3D printing technology,the single factor experiment was used to determine the effects of rotary speed,inclination angle and length of the inclined blade,and chord length of the arc blade on loss rate and removal rate of water chestnut. The structural parameters and motion parameters were optimized. The results showed that the removal rate and the loss rate of the peeler designed was 93% and 24.4% when the rotary speed was 40 r/min,the inclination angle and length of the inclined blade were 82° and 14 mm,and chord length of the arc blade was 22 mm(42.75 mm in diameter),significantly higher than that of manual peeling and mechanical friction peeling.
          2020,39(4):169-174                                                                                                                
          Abstract:
          Because of the existence of soil adhesion characteristics,it often causes soil to adhere to the surface of working parts,which increases the energy consumption of equipment and even prevents normal operation. With the improvement of modern agricultural mechanization and the increasing variety of soil-engaging components,researchers put forward higher requirements for designing and optimizing soil-engaging components. In this study,a paddy field soil adhesion measuring instrument was designed. The single factor experiment was carried out with normal pull-out velocity vn,tangential velocity vτ and paddy field soil spatial depth as influencing factors. The factors affecting the contact interface adhesion were preliminarily obtained. The results showed that the soil adhesion increased with the increase of normal drawing speed vn and tangential velocity vτ,and first increased and then decreased with the increase of spatial depth of paddy field soil.
          2020,39(4):175-181                                                                                                                
          Abstract:
          Dongfanghong-LX754 tractor and Huaifeng1LS-740 subsoiler were used to study the effects of different positions of farm tools on the vibration characteristics of tractor with suspended farm tools. CATIA software was used to establish simplified geometric model of tractor and farm tools. MATLAB was used to write random road surface file,which was imported into ADAMS to write tire property file and establish the mechanical system model of farm tool,tractor and road surface. Effects of the parameters of the suspension device on the vertical vibration acceleration of the driver,the pitch vibration angular acceleration at the seat installation and the vertical vibration acceleration of the tractor body were obtained by simulation. The results showed that when the angle between the inner lifting arm and the horizontal direction increased from 20° to 70°,the driver acceleration peak value reduced to 17.61 from 30.09 m/s2. The peak frequency of vertical vibration increased from 1.36 to 2.12 Hz. Seat installed in longitudinal vibration angular acceleration peak value reduced to 7.56 from 11.12 rad/s2. Tractor barycenter vertical vibration acceleration peak value reduced to 29.33 from 42.42 m/s2. It will provide an important reference for designing vibration damping system of tractor.
          2020,39(4):182-192                                                                                                                
          Abstract:
          The effects of different holding times on the biochar yield,composition,pH,electrical conductivity and pore structure of five kinds of straws including rice,wheat,corn,rape and cotton were investigated.Correlation between the physical and chemical properties of different biochars was analyzed.The results showed that effects of straw type and holding time on the physicochemical properties of biochar fertilizer were significant (P<0.05).The biochar yields and the carbon conversion efficiency of straws ranged from 41% to 61%,and 53% to 65%,respectively.With the increase of holding time,the biochar yields decreased,while the pyrolysis degree and the fixed carbon contents of biochars increased.The pH and electrical conductivity increased with the increase of holding time.The holding time was negatively correlated with carbon yield,H,O contents and volatile matter content of biochars,and positively correlated with fixed carbon content.The optimal holding time is 60-90 min,and the biochars obtained under this condition has a rich pore structure with smooth surface.The biochars with lower H/C and higher pH and electrical conductivity can be used as a good carbon-based fertilizer additive material.
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          Abstract:
          In order to evaluate the breeding effect of the hybrid combination of Barkshire and Etongliangtouwu, the carcass and meat quality traits were measured in 70 Bae hybrid pigs (Barkshire×Etongliangtouwu). The results showed the body weight of Bae hybrid pigs was (109.10 ± 11.01) kg, slaughter percentage was 74.28% ± 1.99%, eye muscle area was (31.40 ± 3.57) cm2, backfat thickness was (31.65 ± 5.66) mm, skin thickness is (3.32 ± 0.74) mm, flesh color score 1 is 3.80 ± 0.77, intramuscular fat content is 1.94%, and the drip loss at 48 hours after slaughter is 2.07%. Thirteen fatty acids were detected in the dorsal longest muscle, of which saturated fatty acid content was 31.92% ± 7.68%, unsaturated fatty acid content was 68.08% ± 7.68%, and inosine monophosphate content was detected in the longest muscle of the back was (3.71 ± 0.42) mg/g. Correlation analysis showed that the fat percentage of the Bae hybrid pigs was significantly positively correlated with the backfat thickness (P<0.01, r = 0.69). Intramuscular fat content was significantly negatively correlated with meat color score 1 (P<0.01, r= -0. 37). inosine monophosphate content was significantly positively correlated with carcass length (P<0.01, r = 0.4). The results of this study showed that the slaughter performance of Bae hybrid pigs is great, the backfat thickness and skin thickness are moderate, the muscle color is bright, the line is good in hydraulic power, and great cross use was obtained. Keywords: Bae hybrid pigs; carcass traits; meat quality traits; fatty acids; correlation analysis
                                                                                                                         
          Abstract:
          Tongcheng pig is the first batch of breeds to be listed on the national protection list of livestock and poultry breeds. It is a representative breed of "Huazhong Two-End-Black pig" and the meat of it tastes delicious, tender and succulent. At the same time, it is found that Tongcheng pig has special resistance to High pathogenic Porcine Reproductive and Respiratory Syndrome virus. In order to retain the advantages of disease resistance and meat quality , and improve the deficiency of slow growth and low lean ratio of Tongcheng pigs, Etong Two-end-black was cross bred by introducing lean meat varieties. To compare the differences between Etong Two-End-Black and Tongcheng pig in nutrition and flavor compounds, amino acids, fatty acids, inosine acids and thiamine in the longissimus dorsi muscle of 30 Etong Two-End-Black and 29 Tongcheng pig were measured. The results showed that there were various kinds of amino acids in the Tongcheng pig muscle, the total content of 16 kinds of amino acids was 19.42±1.31 g/100 g, the content of essential amino acid (EAA) was 8.47±0.98 g/100 g, and the content of fresh amino acid (FAA) was 6.80±0.46 g/100 g. Tongcheng pig was rich in fatty acids and had high nutritional flavor value, the content of saturated fatty acid was 43.04% ± 1.84%, the content of unsaturated fatty acid was 56.96% ± 1.84%, in which the content of monounsaturated fatty acid (MUFA) was 47.47% ± 2.63% and the content of polyunsaturated fatty acid (PUFA) was 9.50% ± 2.50%, and the content of linoleic acid was 8.93%±2.36%. The content of flavor compounds, thiamine was 0.23 ± 0.05 mg/100 g and inosinic acid was 3.23 ± 0.67 mg/g , which were the material basis of Tongcheng meat quality and taste. The content of PUFA (12.08% ± 4.72%), linoleic acid (11.36% ± 4.44%) and thiamine (0.23 ± 0.05 mg / 100 g) in Etong Two-End-Black were significantly or extremely significantly higher than those of Tongcheng, and the above other traits were not significantly different from Tongcheng pigs (P > 0.05). The above results showed that the pork of the two breeds had the characteristics of high nutritional value and unique flavor, Etong Two-End-black pig not only retain the nutritional and flavor of Tongcheng pig, but had higher contents of PUFA and thiamine, which is worthy of further development and utilization.
                                                                                                                         
          Abstract:
          To investigate the changes of hematological traits after infection with highly pathogenic porcine reproductive and respiratory syndrome virus, a total of 72 Large White×Tongcheng advanced generation inter-cross piglets of 5 weeks old ,infected with HP-PRRSV, were used for the artificial infected experiment. The WBC count, the lymphocyte percentage, the monocyte count and the granulocyte percentage were determined at 0,4,7,11,14,21,28,35 days post infection (DPI) ,then were correlated with viremia respectively. The results showed when compared to 0DPI, the WBC count, the lymphocyte percentage and the monocyte count were significantly reduced (P <0.01), and the granulocyte percentage was significantly increased (P <0.01) at both 4DPI and 7DPI, but there were no significant differences for the other DPI. Groups of piglets with PRRS-resistant and PRRS-susceptible were set on the basis of viremia and survive. It was detected that the lymphocyte and the granulocyte percentage were significantly different at 7DPI between groups. The lymphocyte percentage was significantly higher than PRRS-susceptible group(P <0.05), and the granulocyte percentage was significantly lower (P <0.05).For other DPI, as well as other hematological traits, there were no significant differences. Furthermore, the correlation analysis of hematological traits and viremia at all DPI in piglets revealed medium correlations between the hematological traits and viremia (P <0.01). Our current study provides basic data for further research on the changes of hematological traits after PRRSV infection and its relationship with viremia deeply.
                                                                                                                         
          Abstract:
          Tongcheng pig is an excellent representative of local pig breeds in China, it has the advantages of good motherhood, tolerance to roughage, and the meat is tender, juicy and delicious, but it also has the problems of slow growth, thick back fat and low lean meat rate. Therefore, in order to make use of the good meat quality of Tongcheng pig and improve its disadvantageous traits, the lean meat type large white pig was introduced to cultivate a new breed of Etong Two-End-Black. To evaluate the effect of new breeding in this study, the growth traits, carcass traits (carcass length, backfat thickness, eye muscle area, percentage of lean meat, etc.), meat quality traits (meat color, dripping loss, marbling and intramuscular fat content, etc.) and blood physiological and biochemical indexes were measured between Etong Two-End-Black and Tongcheng pigs. The results showed that the daily gain of the Etong Two-End-Black was (596.27 ± 90.24) g / d, which was significantly higher than that of Tongcheng pig ((513.28 ± 90.31) g / d (P < 0.01)). The lean meat percentage of Etong Two-End-Black was (49.56% ± 2.21%) ,which was significantly higher than that of Tongcheng pig (43.47% ± 1.39%, P < 0.01).The backfat thickness of Etong Two-End-Black was (34.73 ± 0.94) mm, which was significantly lower than that of Tongcheng pig((38.80 ± 0.96)mm(P<0.01)). Marbling score and intramuscular fat content of Tongcheng pigs were (3.47 ± 1.16) and (3.45% ± 1.11%) respectively. Except for intramuscular fat content(2.72%±0.87%)of Etong Two-End-Black decreasing, there was no significant difference in other meat quality traits between two breeds. In addition, only part of the blood physiological and biochemical indexes of the two breeds have significant differences. The results illustrated that Etong Two-End-Black has improved their growth and carcass traits while retaining the excellent meat quality traits of Tongcheng pigs. Therefore, the study can provide scientific basis for further popularization and utilization of Etong Two-End-Black.
                                                                                                                         
          Abstract:
          How to promote the connection and cooperation among farmers is a key problem in rural development and governance. Based on the theory of collective action, regarding the cooperation among farmers as a kind of collective action, this paper discusses the specific process of peasants" self-organization and cooperation through investigating the case practice of the construction of beautiful village, and analyzes the mechanism and behavior logic of the cooperation. It is found that the cost-sharing of key groups, the establishment of trust network and the action ethics within the community jointly shape the cooperation willingness and cooperation ability of farmers, and ultimately promote cooperation. Specifically, the return of economic elites solves the problem of resource supply to start cooperation and provides a prerequisite for cooperation; the return of capital and governance of capable people cultivate the trust structure and institutional strength to maintain cooperation, which provides a constraint guarantee for cooperation; the action ethics and emotional morality of village members shape a unique cost-benefit distribution and provide an important support for cooperation. Therefore, the construction of beautiful villages should also pay attention to the construction of internal self-organization forces in order to ensure the sustainable power source of village development and revitalization.
                                                                                                                         
          Abstract:
          The pepper root system and soil samples were collected from the pepper planting area in Qimaba Township, Lvchun County, Honghe Prefecture, Yunnan Province. To investigate pepper phytophthora root rot and calculate its incidence and disease index, The spore density, richness, diversity index and mycorrhizal infection rate of arbuscular mycorrhizal fungi(AMF) in the rhizosphere and around roots of pepper were investigated by wet-screen precipitation method and Plant root staining. Then the final data were analyzed by SPSS software. The results showed that when the mycorrhizal infection rate was 62.5%, the spore density was also the highest, reaching 11.725 spores/ g, the incidence and disease index of pepper phytophthora root rot were the lowest (20% and 9, respectively). when mycorrhizal infection rate and spore density were the lowest 11% and 2.475 spores/ g, the incidence and disease index of pepper phytophthora root rot were the highest at 80% and 53.5, respectively. The results of the correlation analysis showed that the spore density, richness and mycorrhizal infection rate of the AMF were negatively correlated with the incidence and the disease index of pepper phytophthora root rot. That is, the higher the spore richness and spore density of AMF, the higher the mycorrhiza infection rate, the lower the incidence of pepper phytophthora root rot and the smaller the disease index. It follows that the existence of AMF in pepper root soil can enhance the disease resistance of pepper and reduce the occurrence of diseases.
                                                                                                                         
          Abstract:
          The purpose of this study was to explore the effect of PGF2α signal on the oocyte and early embryo in buffalo, the expression patterns of PTGFR in buffalo oocytes and early embryos development were determined by immunofluorescence and fluorescence quantification. Subsequently, the effects of AL-8810 on the maturation efficiency of oocytes and the efficiency of embryonic development in buffalo were studied by adding different concentrations of AL-8810 into the oocyte maturation medium and embryonic development medium. The results showed that PTGFR protein was widely distributed in buffalo oocytes and embryos, and the expression level of PTGFR gene was significantly higher in 4-16 cell stage than in unfertilized oocytes and morulae (P<0.01). AL-8810 had no significant differences effect on the nuclear maturation efficiency of buffalo oocytes (P>0.05), however, high concentration treatment group(1 600 nmol/L) significantly reduced the early apoptosis rate of buffalo oocytes (P<0.05). AL-8810 at the concentration of 100 and 800 nmol/L significantly improved embryonic development efficiency in 16 cell stage, and the morula formation rate was the highest in the 800 nmol/L group. The above results indicated that inhibition of prostaglandin PGF2α signal effectively improved in vitro maturation quality of oocytes and early embryos development potential in buffalo.
                                                                                                                         
          Abstract:
          Bi系光催化材料是近年來被廣泛研究的一類新型光催化劑,具有獨特的層狀結構和合適的帶隙,價導帶位置可調,是一類性能優異、環境友好型、結構可調的光催化劑,在環境與能源領域具有廣闊的應用前景。本文介紹了Bi系光催化材料的種類,系統綜述了形貌調控、表面缺陷引入、晶面構建、表面等離子體修飾、元素摻雜、構建異質結等結構調控方法,分析了光催化性能增強作用機制,并重點總結了鉍系光催化材料在水處理、空氣凈化、固氮、產氫等環境凈化和能源轉化領域的應用研究進展,最后討論了該領域所面臨的挑戰,并對Bi系光催化材料未來的發展進行了展望。
                                                                                                                         
          Abstract:
          The article gives an empirical test to the impact of non-agricultural employment experience and behavioral capacity on the operating efficiency of new-type professional farmers, adopting a two-stage model of DEA-Tobit and an mediation effect model, which uses 501 questionnaire survey data from the provinces of Guangdong and Jiangxi, based on the theoretical analysis. The results show that there is low overall efficiency in the new type of professional farmers, and more room for later improvement. The non-agricultural employment experience plays a significant role in promoting the comprehensive management efficiency of new-type professional farmers. It has a positive impact on the work experience and business experience to the comprehensive management efficiency of new-type professional farmers, but the impact of political experience fails to pass the significance test.Behavioural ability not only promotes the improvement of the comprehensive management efficiency of new professional farmersdirectly, but also plays a part of the mediating role in the positive relationship of“non-agricultural experience-management efficiency”.The effects of control variables, such as academic qualifications and terrain features, pass the significance test, when the rest of the control variables fails to pass the significance test. Therefore, workers with rich non-agricultural employment experience should be encouraged to take up employment in agriculture, and the differentiated cultivation policies have to be adopted for workers, who have different employment experiences and are willing to engage in agriculture forthe rural revitalization.
                                                                                                                         
          Abstract:
          With the rapid development of the industrial sector and the restrict of the household land holding, the non-agricultural income has gradually become the main source of rural household, which has a significant pure income effect. It makes the labor efforts and the incentive on farmers acquiring agricultural technology of agricultural labor fluctuate , and change the contribution of labor efforts to the agricultural high-quality growth. The labor efforts under the restriction of the land holding contribute 72.5% to the improvement of agricultural high-quality growth from 1985 to 2016, and this contribution declines over time, but the decline rate is more and more slow, and the less developed the province is ,the smaller the decline of that share is.
                                                                                                                         
          Abstract:
          China is the promoter, contributor and leader of the world's important agricultural heritage protection, providing the world with China's wisdom and China's program. This paper reconstructs the connotation and characteristics of important agricultural heritage from two dimensions of world heritage system and agricultural heritage system. This paper summarizes China's main progress in the field of important agricultural heritage protection. The work of excavation and identification of important agricultural heritage has been carried out in an all-round way, the protection and management mechanism has been continuously improved, multi-disciplinary research has been gradually expanded and deepened, social influence has been significantly enhanced, multi-functional values have begun to show, and international exchanges and cooperation have become increasingly frequent. This paper analyzes the dilemmas and problems faced by the protection of important agricultural heritage, including the deviation between the understanding of connotation and the concept of protection, the insufficient support of heritage protection policies, the imperfect mechanism of protection and management, the lack of scientific research and management talents, and the need to strengthen international influence and protection. In order to further promote the protection of important agricultural heritage, it is necessary to strengthen the understanding of dynamic protection and scientific utilization, improve the system and mechanism of management and utilization, strengthen policy support, promote scientific research and personnel training, and strengthen China's leading role in this field.
                                                                                                                         
          Abstract:
          The "one-step method" SFA model was used to empirically explore the technical efficiency of 603 family farms and its influencing factors, and analyze the relationship between different agricultural factor allocation modes and the technical efficiency of farms. The results show that: ①The input of land, labor force and capital has a significant effect on agricultural production, but the comprehensive technical efficiency of farm depends more on the efficiency of capital scale; ②The average technical efficiency of the farm is 0.58, there is a 42% loss of technical efficiency;③Different agricultural factor allocation has a significant impact on the change of farm technical efficiency. Compared with no-land transfer households, land transfer households have higher management technology efficiency, compared with non-agricultural employment households, non-agricultural employment households have higher management technology efficiency; ④The farmer's age and educational level have a significant negative effect on the technical efficiency of the farm, planting Cash crop, using new agricultural technologies, setting production standards, joining farmers' cooperatives, trademark brands, and establishing stable marketing channels have significantly improved the farm's technical efficiency. Main conclusion: in order to further improve the efficiency of agricultural technology and factor allocation, we should accelerate the process of rural land circulation marketization and promote the transfer of agricultural labor force to non-agricultural industries. As a farm operator should also change their ideas and management methods to improve the level of farm management and agricultural technology efficiency.
                                                                                                                         
          Abstract:
          Frequent events of winter haze in China have caused various health issues in large populations. It is believed that the sulfate aerosol produced by a series of physical and chemical reactions of SO2 is an important culprit of haze generation, and the heterogeneous reactions of SO2 on mineral particles is particularly important. Therefore, clarifying the formation mechanism of sulfate on mineral particles is a key scientific problem to analyze the formation of haze. In this paper, the research progresses about the typical heterogeneous reactions of SO2 on various mineral particles were reviewed, the effects of multi-pollutant coexistence system, humidity and light on heterogeneous reactions of SO2 were discussed, the future work related to heterogeneous reactions was also proposed. This paper aims to gain a deep understanding of the mechanism of mineral particles promoting the formation of sulfate and attempts to provide theoretical support for effective haze control.
                                                                                                                         
          Abstract:
          Agricultural production outsourcing has increasingly become an important way to promote large-scale agricultural management. At present, the main problem faced by farmers in the outsourcing of production links has changed from "whether to participate" to "the degree of participation". For this reason, based on the field survey data of wheat growers in Linyi, Shandong, this paper uses a censored regression model to conduct an empirical analysis of the reasons why farmers ’s subjective outsourcing willingness and objective outsourcing are very different. The conclusions show that the main reason for the huge difference is the information asymmetry, the contradiction between supply and demand, and the difference in farmer""s land endowment. These findings provide a useful reference for promoting the balance of supply and demand in the agricultural social service market.
                                                                                                                         
          Abstract:
          Aiming at the working conditions of rice stubble with high stubble, heavy soil adhesion and large fluctuation of water content in the rice-rapeseed rotation area, combined with the agronomic requirements that surface flatting, seedbed crushing, straw returning to the field and water draining to the furrow for winter rapeseed direct-seeding, considering the production practice that the single function tillage machine is not conducive to scramble for farming time and will compacting soil as it repeatedly working in the fields, a kind of seedbed preoaration technology scheme of "left-turn disc plough group burying stubble, reverse rotary knife roll crushing soil, side mounted plough ditching furrow" was put forward, and a kind of driven disc ploughing and reverse rotary tilling integrated machine for rapeseed seedbed preparation was designed. The machine is mainly composed of driving disc plough group, reverse rotary blade roller, front ditch plough and rear ditch plough and soil-flated plate, which can realize the functions of surface flatting, seedbed crushing, straw burying and furrow ditching. The spatial layout design principle of each tillage component was analyzed, and the structure parameters and working parameters of drivin disc plough group and reverse rotary blade roller were determined. Field experiment showed that: The average values of tillage depth, furrow depth, furrow width, compartment flatness, the rate of soil pulverizing and straw burying in seedbed after preparation machine operation were 173.2mm, 190.2mm, 401.4mm, 11.6mm, 95.9% and 90.2% respectively; The average values of stability coefficient of tillage depth, furrow depth and furrow width were 85.6%, 86.7% and 84.6% respectively. And these can meet the agronomic requirements of seedbed preparation for rapeseed mechanized direct-seeding.
                                                                                                                         
          Abstract:
          Abstract:[Objectives] The content levels of heavy metals Cd, Hg, As, Pb, Cr, Cu, Ni and Zn in 208 surface soils in the study area were detected. The environmental baseline value of heavy metal elements and the accumulation of changes relative to background values were obtained in regional surface soil. Based on this, the disturbance degree of heavy metal elements in regional surface soil by human activities can be judged. [Methods] Standardized method and relative cumulative percentage statistical method were used to calculate the environmental baseline value and deviation of heavy metals in regional surface soil. The average environmental baseline values obtained by these two methods were taken as the environmental baseline values of heavy metals in the surface soil of the study area. [Results] The content levels of heavy metals Cd, Hg, As, Pb, Cr, Cu, Ni and Zn in the surface soil of the monitoring points in the study area were not exceed the risk screening values for soil contamination of agricultural land. The environmental baseline values of heavy metals Cd, Hg, As, Pb, Cr, Cu, Ni and Zn obtained by these two methods were 0.22 mg/kg, 0.09 mg/kg, 13.34 mg/kg, 30.7 mg/kg, 82.0 mg/kg, 29.7 mg/kg, 38.0 mg/kg and 89.1 mg/kg respectively. The relative deviation ranged from 0.5% to 12.0%. [Conclusions] The environmental quality was generally good of regional surface soil. Compared with the background value, the environmental baseline value increased in different degrees of heavy metals Cd、Hg、As、Pb、Cr、Cu、Ni、Zn in regional surface soil, but the change rate was less than 50%, and the increase was not significant. Among them, the cumulative index evaluation grade of Cd reached slight accumulation, while other heavy metals elements had no obvious accumulation. This shows that heavy metal elements in the surface soil of the study area have been disturbed by human factors to a certain extent, and the influence degree was slight.
                                                                                                                         
          Abstract:
          Reactive oxygen species (ROS) are a class of oxygen free radicals or non-radical derivatives of oxygen with oxidizing ability. Utilizing ROS to degrade environmental pollutants is one of the greenest and most effective chemical means for pollution control and environmental remediation. However, there are different types and various generating-routes of ROS, and the mechanisms of environmental pollutant degradation and removal are distinguishing. It is significant to further understand the production and action mechanism of different ROS in environmental pollutant degradation and transformation. This article reviews recent research progress on ROS (hydroxyl radical, superoxide anion, singlet oxygen and hydrogen peroxide) for environmental pollutants removal in recent years and introduces several common ROS and their generating pathways and detection methods. We also summarize the applications of ROS in air purification, organic wastewater treatment, bacterial inactivation and finally discuss the major problems about ROS for environmental pollutants degradation and prospect the application of ROS in pollution control and environmental remediation.
                                                                                                                         
          Abstract:
          Based on the survey data of 123 small and medium-sized agricultural e-commerce enterprises in Ganzhou, Jiangxi Province and Lishui, Zhejiang Province, making an in-depth study of intermediary effect of Enterprise Innovation behavior in the relationship between the three dimensions of dynamic capability (Knowledge acquisition, Integration Utilization, Reconstruction Transformation) and Enterprise performance. The research shows that the three dimensions of the dynamic capability have a significant positive effect on the performance of the enterprise, and the innovation behavior of the enterprise has an intermediate role between the dynamic capability and the enterprise performance relationship. Specifically, the enterprise knowledge acquisition ability improves the enterprise performance through the internal system reform and the market development behavior; the enterprise integration utilization ability improves the enterprise performance by acting on the enterprise new technology adoption behavior; the enterprise reconstruction transformation ability improves the enterprise performance by acting on the enterprise market development behavior. Therefore, the small and medium-sized agricultural product e-commerce enterprise, based on its own capability advantage, adopts the matching innovation behavior, which will help to improve the performance level.
                                                                                                                         
          Abstract:
          With the change of agricultural endowment and induced technological progress in China, farm household transform inputs structure timely, which affect the growth of labor productivity. This paper constructs elastic coefficient of input factor allocation ratio affecting labor productivity and examines the effect of rural labor transfer on labor productivity of maize, based on the expanded cobb-douglas production function. The results show that: (1) factor allocation structure adjustment enhances maize’s labor productivity because technical equipment allocated to unit labor has been improved significantly, through reducing the labor and increasing fertilizer and machinery. (2) At the national level, the elasticity of fertilizer-labor ratio affecting on maize’s labor productivity is the most significant positive effect, as well as the elasticity of seed-labor ratio and machinery-labor ratio. (3) At the regional level, the elasticity of fertilizer-labor ratio, seed-labor ratio, machinery-labor ratio and pesticide-labor ratio are significantly positive in North China. The elasticity of pesticide-labor ratio is negative in Northeast China and the elasticity of machinery-labor ratio isn’t significant in Southwest China. (4) Compared with labor-saving technology, land-saving technology appears more significant effect on maize’s labor productivity. The policy implication is that improvement the quality of input factors and optimization the structure of factor allocation, as well as continuing to promote rural labor force transfer to nonagricultural sector. Especially, it emphasizes the matching of the inputs factor, the integration of technical equipment and promoting agricultural socialized technical service.
                                                                                                                         
          Abstract:
          In this experiment,artificially wounded yam tuber were cuerd with 1 mmol / L BABA with 1 mmol / L NaHCO3 at 35℃ for 7days. The occurrence and accumulation of lignin and suberin polyphenolics, the weight loss and lession diameter, phenolic metabolism and active oxygen metabolism related indexes at the cut sites of yam tuber, were measured to evaluate the effects of treatments .The results demonstrated treated by 1 mmol / L BABA with NaHCO3 could effectively reduce the decay of wounded yam tuber with lignin and suberin polyphenolics accumulation at the wounding sites through activation of the ROS and phenolic metabolism levels. It was suggested that the treatment can inhibit the infection of pathogens effectively during curing time,and advance the callus process in wound site.
                                                                                                                         
          Abstract:
          Eggs provide various of nutrients for human beings, such as proteins, lipids, and vitamins. Besides of the processing properties from egg white, bioactive peptides obtained by the enzymatic hydrolysis method have diversiform biological functions. In this paper, biological functions such as of anti-oxidation, prevention of cardiovascular diseases, promoting mineral absorption, anti-diabetes, and regulating intestinal health were summarized, and the structure-activity relationships of egg white peptides from duck egg and chicken egg were also reviewed. It was found that egg white-derived angiotensin-converting enzyme (ACE) inhibitory peptides could affect their ACE inhibitory activity when the C-terminal was proline, leucine, and the N-terminal was aromatic or alkaline amino acid. Hydrophobic amino acids in N-terminal, and aromatic amino acids in the primary structure of antioxidant peptides from egg white can greatly improve the antioxidant capacity of the peptides. Glutamic acid in the first C-terminal, and phosphorylation of serine in the sequence of egg white-derived calcium absorption peptides have important contributions to the calcium absorption. However, bioactive peptides obtained by hydrolysis were confirmed to have different bioactivities, low yield and significantly different structures, making it difficult to obtain universal structure-activity relationship conclusions. Thus, the purpose of this paper is to provide a basis for the high-valued utilization of egg white, and a certain application for the production of egg white bioactive peptides as nutritional supplements, functional nutritional health products and therapeutic drugs, as well as to put forward a new prospect for the research of bioactive peptides.
                                                                                                                         
          Abstract:
          Whether it is in theory or in practice, the problem of poverty management in non-poor areas has been receiving much attention as an important part of China's fight against poverty.In this study, through empirical investigations of poor counties (T counties) and non-poor counties (H District) in W city, it was found that there is a problem of unbalanced policy assistance in poor counties and non-poor counties. And poor people may fall into the welfare trap, and non-poor people face a cliff effect. By sorting out the current status of the poverty-stricken people who enjoy poverty alleviation policies, this paper compares and analyzes the differences between the poverty-stricken groups and non-poor groups who enjoy the poverty alleviation policies. And to explore the unexpected results and risks of policy superposition in practice, in order to grasp the connotation of the policy and solve the relationship between policy dependence and government input.This article proposes that the formulation and development direction of poverty alleviation policies should pay more attention to the long-term development and equity of society, and gradually improve the risk governance mechanism of poverty alleviation policies.
                                                                                                                         
          Abstract:
          As the direct product of targeted poverty alleviation in China, " Migrant Communities " have made great achievements, but they should also keep risk awareness at all times. Although the relocation of poor households in the " Migrant Communities " of urban centralized resettlement has realized the "Leaping urbanization" of living space, household registration and part of public services with the help of national forces, it has not realized the "ability urbanization" and "quality urbanization" of production mode, life style and civilization quality. This "semi urbanization" makes the relocation of poor households in such a city In the "high risk" society, there is a contradiction that individual ability and quality can not meet the requirements of cities and towns. Therefore, they may encounter "ten risks" including employment risk, economic risk, dependence risk, trust risk, psychological risk, development risk, etc. In order to maintain social stability, we should increase the follow-up support for poverty alleviation and relocation, improve the risk prevention and control mechanism of "easy to help communities" and strengthen the construction of social support system of " Migrant Communities " to improve the social stability risk governance capacity of "easy to help communities".
                                                                                                                         
          Abstract:
          Objective: To figure out the effects of intercropping corn on the growth and quality of Pinellia ternata. Under normal Pinellia sowing density, two intercropping methods of corn wide-narrow rows and equal rows and three corn planting distances of 35, 50, and 65cm were adopted to measure the changes of Pinellia ternata growing environment, growth, yield and quality of P. ternata, then the land equivalent ratio and interspecies competitiveness under the intercropping system were further analyzed.The results showed that with the increase of corn planting density, the canopy light intensity of , the leaf surface temperature and the soil temperature of Pinellia ternata were all decreased, whereas the main leaf area, petiole length and SPAD value of P. ternata were significantly (p≤0.05) increased in the inter cropping system. The land equivalent ratio in the intercropping system increased, and corn was more competitive than P. ternata; Intercropping corn significantly increased Pinellia ternata yield and thousand-grain weight.under the condition of corn with a 35 cm equal rows plant spacing had the highest Pinellia ternata yield , an increase of 44% compared to Pinellia ternata monoculture;The quality of Pinellia ternata has no significant difference compared with the control ,and all meet the requirements of Chinese Pharmacopoeia. Intercropping corn provides a better growth environment for Pinellia ternata, makes Pinellia ternata oleifera better growth, and improves Pinellia ternata yield.
                                                                                                                         
          Abstract:
          Guiding residents to save for retirement is one of the important ways to alleviate the economic pressure . Based on the survey data of China Ageing Finance Forum , using ordered probit model, this paper empirically tests the impact of income level on the retirement saving behavior of urban and rural residents. The results show that: income has a positive effect, urban residents' retirement saving is more affected by income, with lower threshold; the income threshold of retirement saving in the northeast is the highest, while that in the east is the lowest; the retirement saving behavior in the west is the most sensitive to income, and that in the central is the least sensitive.In the lower income group, the elderly residents' retirement saving is more susceptible to income; in the higher income group, the elderly residents' retirement saving is more susceptible to income.The influence of income in the youngest and oldest urban residents is greater than that of the rural residents, while the opposite is true for the middle-aged groups. Therefore, it is necessary to strengthen the ageing financial education in rural areas, change the concept of the aged and improve the consciousness of retirement saving , so as to reduce the pressure of the aged economy.
                                                                                                                         
          Abstract:
          The first secretary system is an institutional exploration and innovation in the field of poverty alleviation in China, which presents the characteristics of complexity and diversification in the practice of grassroots governance. After entering the village, the first secretary realized the integration of national governance and grass-roots autonomy at the village level, forming a differentiated two-track interactive governance structure and practice style. The survey found that there are three modes of interaction between the first secretary and the village society, which are arranged alternative, cooperative assistance and passive alienation. The differences in the practice of the first secretary system are shaped by three mechanisms: the resource foundation and governance capabilities at the village level, the village positioning and resource matching at the local government level, and the resource network and career pursuit at the individual level of the first secretary. The first secretary system has produced problems of accuracy and sustainability in practice. Optimizing the performance of the first secretary system should be carried out from the aspects of organizational system reconstruction and accurate resource docking, in order to promote the endogenous poverty alleviation and independent development capabilities Promote.
                                                                                                                         
          Abstract:
          Telomerase has the function of maintaining telomere length, and its catalytic subunit TERT (Telomerase Reverse Transcriptase) is tightly regulated in higher organisms such as mammals, and is usually not expressed in somatic cells. However, in lower eukaryotes such as invertebrates, TERT is often expressed in somatic cells, but the physiological function is not clear. In order to clarify the physiological function of TERT, the TERT gene of Lipaphis erysimi (Kaltenbach) was cloned and analyzed for its spatial and temporal expression. The results showed that the CDS region of the radish TERT gene was 2658 bp and capable of encoding 885 amino acids. Its secondary structure contained 41 α-helices and 60 coiled coils. Phylogenetic analysis indicated that the Lipaphis erysimi TERT gene has the closest relationship with Diuraphis noxia, and has high homology with Myzus persicae and Acyrthosiphon pisum, but has low homology with other insects. Real-time quantitative PCR showed that the TERT gene was expressed in all ages and tissues during the growth and development of Lipaphis erysimi,and the relative expression of adult TERT gene was higher than that of 1st, 2nd, 3rd and 4th nymphs. The expression of TERT gene in the abdomen of the Lipaphis erysimi was the highest, followed by the head, and the lowest in the chest, but lower than the expression of the whole worm. This study laid the foundation for further study of the physiological functions of TERT in insects.
                                                                                                                         
          Abstract:
          The yield of rice is closely related to the number of panicle of rice and the weight of panicle, and accurate prediction of rice yield can accelerate the breeding speed. In order to study the relationship between rice yield and plant phenotypic characteristics, this experiment took potted rice as the research object, using visible light images combined with image processing technology for feature extraction, and obtained 51 phenotypic traits of whole rice. Combined with deep learning technology, the Faster R-CNN convolutional neural network training model was used to detect the number of rice spikes. At the same time, the Rice-PanicleNet model was trained using the SegNet network framework to segment the rice spikes to obtain the binary image of the rice spikes. , Combined with image processing technology to extract 33 phenotypic feature data of the panicle. A total of 85 phenotypic features were extracted from the image. The artificial measurement data in the experiment included the fresh weight and dry weight of potted rice panicle. Normalize all the data to build a prediction model of fresh weight and dry weight of potted rice panicles. Finally, select the most according to the model's decision coefficient R2, average relative error (MAPE) and standard deviation of relative absolute value (SAPE) Excellent prediction model. The prediction results show that the panicle characteristics prediction effect is the best, and the decision coefficients R2 of the predicted value and the real value of the model with the best effect are 0.787±0.051 and 0.840±0.054, respectively. In this study, combined with deep learning, the number of panicle and panicle characteristics that are difficult to obtain automatically by traditional methods are extracted, which provides a new idea and method for rice panicle weight prediction, and further improves the accuracy of rice panicle weight prediction.
                                                                                                                         
          Abstract:
          In this paper, the impact of agricultural insurance exclusion on farmers' income was systematically investigated. The micro-level data in this paper were generated from a survey about agricultural insurance in 12 counties of 6 northern provinces in 2015. To begin with, Based on OLS and Oaxaca-Blinder strategy, we get conclusion that agricultural insurance exclusion has a significant negative impact on farmers' income, and the difference in agricultural income between excluded farmers and non-excluded farmers is 6%. Furthermore, the Propensity Score Matching method is adopted to correct the possible sample selectivity bias. The main above conclusion is still robust. We adopted sub-sample studies to deal with heterogeneity. The empirical result shows that the increase of agricultural income for young farms and expanded non-excluded farmers is obvious. In addition, compared with the farmers with higher risk of disaster, low affected farmers who are not excluded have a low probability of being affected and getting compensation. So agricultural premiums become additional agricultural costs and reduce their income. Therefore, policy implications have been generated.The government need to promote policy-based agricultural insurance by increasing compensation level, expanding scope and designing more insurance plan. By reducing the exclusion, agricultural insurance would play more significant rolde in promoting income of farmers.
                                                                                                                         
          Abstract:
          Aiming at the disadvantages of the present traditional silage of green or semi-green corn stalk powder, the compactness of lapping and pressing is small, the degree of anaerobic is not enough, the ammoniation is not good, there are some rotten and deteriorated, and it is inconvenient to seal in the process of opening and using. The key part of the high compression ratio packer, compression devices is designed. The compression molding experiments of four times, five times and six times compression ratio were carried out for the key component compression device in advance. The optimal compression ratio of 1:6 was determined through orthogonal design and multi-level analysis. Based on the quality purpose of improving packaging forming rate, the compression box is used by two hydraulic cylinders to open and close the feeding movable cover plate, two main hydraulic cylinders to compress the pressure, one hydraulic cylinder to push out and the pressure maintaining box to complete the compression and pressure maintaining forming. According to the properties of material expansion and springbackdue to stress relaxation after compression,the design experiment was carried out.the length of the pressure maintaining box is 600mm, the width is 300mm and the height is 365mm. After design and inspection the internal effective working range of the compression device is 1800mm in length, 600mm in width and 365mm in height,and the volume compression reaches a high compression ratio of 1:6, the anaerobic conditions is improved, the degree of ammoniation is improved and the use is more convenient.
                                                                                                                         
          Abstract:
          Ammonia selective catalytic reduction of nitrogen oxides (NOx) technology with V2O5-WO3 (MoO3) / TiO2 as the core catalyst is currently widely used. But it has many problems such as narrow and high temperature window, easy to poison by alkali inactivation, vanadium"s biological toxicity and secondary pollution to the environment, which require researchers to develop new efficient and environmentally friendly catalyst systems. Due to its unique structure, perovskite materials have good mid-high temperature activity, excellent high temperature resistance, sintering resistance and environmental protection and harmless characteristics, which has attracted more and more concerns in the field of selective catalytic reduction of NOx. This paper summarized the research progress of perovskite NH3-SCR catalysts in recent years. The main types of perovskite catalysts, denitration activity, structure-activity relationship and reaction mechanism were comprehensively discussed. The future possible development direction of perovskite NH3-SCR catalysts are prospected.
                                                                                                                         
          Abstract:
          The current global food security situation is still very serious. The development of globalization and the evolution of the international situation make it difficult to completely solve the food security problem through established international governance rules, and a new global governance mechanism needs to be established urgently. As an important means of global governance, especially global agricultural and food governance, digital governance tools have attracted the attention of the international community in recent years. All kinds of international organizations, research institutions and collaborative mechanisms composed of multilateral interest groups have participated in digital governance. Digital governance plays a positive role in global resource allocation, national policy making and the realization of sustainable development goals, but its deep discourse, rules and powers reflect that global governance is still dominated by the west at the present stage. In the process of forming a new global governance pattern, China should more actively enhance its international voice, change unfair international rules, balance the long-term dominant power of western developed countries in global governance, better safeguard national food security, and enhance its overall international influence.
                                                                                                                         
          Abstract:
          Germany is one of the birthplaces of cooperatives. Based on a two-week special survey of German cooperatives, this paper focuses on the adaptive characteristics, trend characteristics and social system background of German farmers' cooperatives. It is found that the German farmers' cooperatives have the adaptability characteristics of complete hierarchical organization system, diversified and specialized industrial types, comprehensive and diversified service content, institutionalized daily operation system, regional stability of service and organic industrial development. It also has the trend characteristics of increasingly obvious enterprise, decreasing absolute quantity, increasing scale strength, professional management team and diversified earnings distribution. Moreover, the farmer association system, perfect social security system, perfect social service system and good social credit system all over Germany constitute the "four rounds" to drive and guarantee the sustainable and healthy development of farmer cooperatives. Finally, the paper summarizes and analyzes the problems and challenges faced by the farmers' cooperatives in China, such as the unsynchronized growth of quantity and quality, the increase of heterogeneity of members, the imperfection of supporting policies, the lack of service-oriented cooperatives, and the indefinite debate on attributes, and proposes to promote the quality of farmers' cooperatives, conform to the declining quantity and the trend of enterprise development, and build a driving force for the development of farmers' cooperatives in China“ Four rounds "to encourage in-depth Union and cooperation among farmers.
                                                                                                                         
          Abstract:
          "Cognitive tax" is actually a metaphor used to express the short-sighted behaviors, ignorant desires and missed opportunities in the decision-making process of the poor affected by poverty, and the lack of material conditions and social support. And additional cognitive resources consumed by personal abilities. In this context, this paper uses the empirical research data of Province G to test the application of "cognitive tax" in China's precision poverty alleviation field, and finds that poverty scenarios will lead to a shortage and rigidity of thinking cognition, such thinking cognition, especially thinking out of poverty Cognition and investment thinking cognition are obviously negatively correlated with poor households' education level, health status, poverty alleviation psychology, language skills and behavior choices. At the same time, although the shortage of thinking and cognition will affect the culture, body, psychology, language and behavior of the poor households, the most important thing is to affect the psychology, language and behavior of the poor households, which in turn makes them dependent on the psychology and triggers continued poor. Further investigation revealed that the mechanism of the persistent poverty caused by the "cognitive tax" is that it will cause the poor to pay too much attention to scarce resources, produce attentional bias, and lack confidence and passion for life; it will cause the cognitive load of poor households and make them miss the opportunity to get rich out of poverty. ; Insufficient attention to education, triggering intergenerational transmission of poverty. In short, the research in this paper confirms the applicability of the application of the “cognitive tax” in cognitive poverty and cognitive decline in poverty alleviation in China in the poverty alleviation field. The localization and localization of "tax" were discussed. Therefore, enriching the cognitive resources of poor households is the primary choice to get rid of poverty.
                                                                                                                         
          Abstract:
          The collective governance is an important way to solve the problem of the absence of the governance subject of farmland water conservancy facilities and realize the virtuous circle in which facilities are used and managed. This paper explores the collective governance of small-scale irrigation and water conservancy facilities from the perspective of generalized morality and public leadership. Our purpose is to solve the problems of lack of incentive mechanism and low governance performance, and finally break through self-governing dilemma of small-scale irrigation and water conservancy facilities. The data used in this paper are micro-village survey data of 723 households in Ningxia, Shanxi and Shandong provinces along the Yellow River basin. This paper mainly studied the collective governance of small-scale irrigation and water conservancy facilities. A Multi-group Structural Equation model was selected to analyze the data based on the household agricultural income and province. The results showed that generalized morality and public leadership can significantly positively affect the collective action and governance performance. Collective action had significant and positive effects on the collective governance performance. The public leadership and households’ generalized morality promoted each other remarkably. Multi-group analysis showed that the household agricultural income level and province can significantly moderate the collective action and governance performance of small-scale irrigation and water conservancy facilities. Therefore, the government can promote the collective governance of small-scale irrigation and water conservancy facilities by deepening the cultivation of generalized morality, training village leaders and encouraging village elites to govern villages by combining the agricultural income in different regions.
                                                                                                                         
          Abstract:
          The diseased soil containing pathogens of Fusarium oxysporum f. sp. was used as the material. Using the pot experiment to explore the control effects of Bacillus megaterium B213, Bacillus polymyxa B207, and Bacillus subtilis B204 alone or in combination on cucumber fusarium wilt and its mechanism. The results showed that the three microbial agents alone or in combination could effectively inhibit the occurrence of cucumber fusarium wilt and significantly increase the biomass of cucumber. The effect of the two microbial agents in combination was better than that of single microbial agent. And the effect of the three microbial agents in combination was better than that of the two microbial agents. 35 days after transplanting cucumber seedlings, compared with the control group, the incidence of cucumber fusarium wilt in the three-agent combination group was reduced by 79.99%; the dry weight of cucumber plants was increased by 6.92 times; the activities of plant resistance enzymes, such as acid lyase, polyphenol oxidase, and peroxidase increased by 60.02%, 28.90%, and 108.60% respectively; the number of rhizosphere soil Fusarium oxysporum decreased by 2 orders of magnitude. These effects may be related to the antagonism of these three Bacillus agents to pathogenic bacteria, phosphorus dissolving ability, and secretory ability of indoleacetic acid, protease, chitinase and ferrophilin.
                                                                                                                         
          Abstract:
          From the perspective of political participation, the villager autonomy which is represented by the village elections must be shaped in a certain economic system, no matter as a kind of liberal idea or as a democratic system. And this paper takes the opportunity of a new round of agricultural land property rights system reform in China"s rural areas currently, adopts the survey date of 230 administrative villages, 6940 families nationwide of China Labor-force Dynamic Survey in 2016 which is on the basis of conducting theoretical analyses in the relationship between disposing capacity of property and the executing status of property, and uses instrument variables, two-stage estimation and other methods to answer the question that whether the economic right of determining the agricultural land property can bring more extensive political participation in rural areas by analyzing the election effect of determining the agricultural land property. And it is found that: Firstly, at present, the action of determining the agricultural land property surely significantly increased the enthusiasm of farmers to participate in village elections, but this effect was practicable only in the households engaged in agricultural production. Secondly, compared to non-agricultural labors, the action of determining the agricultural land property can enhance the enthusiasm of agricultural labors to participate in village elections in households engaged in the agricultural production. Moreover, compared with the male labor forces, the action of determining the agricultural land property has a more significant effect on the election to the female labor forces. And the internal mechanism of this action is possibly because the issuance of agricultural land property certificate increases the agricultural producers. Especially at present, the main body of agricultural production is female, and they extremely pay attention to the agricultural incomes. And then, it improves the enthusiasm of agricultural producers to participate in village democratic elections, expands their disposing capacity of property right and obtains expected agricultural benefits by taking part in democratic elections and making decisions of collective actions. Finally, this paper puts forward corresponding measures and suggestions.
                                                                                                                         
          Abstract:
          “Adjacent Governance” originated from the adjacent area of Zhejiang and Shanghai and provides a reference for regional cooperative governance. This model keeps the administrative division and administrative system intact, while the adjacent areas are deeply connected in regional cooperative governance. It is based on rationalized party organization, government cooperation, industrial development, and community governance. Main industries are key elements in promoting regional cooperation and public governance, the essence of which is the process of “rationalization of local issues” and “publication of civic issues”. “Adjacent Governance” is underpinned by adequate interregional linkages, interaction between administration and autonomy, cooperation at the industrial level, and the embedding of farm livelihoods and public governance. Despite its limitations, “Adjacent Governance” provides guidance for regional cooperative governance in terms of sources of motivation, articulation mechanisms and forms of realization.
                                                                                                                         
          Abstract:
          Biomass combustion product rice husk ash was selected as the carrier, and Ni-Mg/RHA catalyst was prepared by co-impregnation method. The catalytic performance of Ni-Mg/RHA for steam reforming of toluene was studied using toluene as a model compound of biomass tar. The effects of Ni and Mg loadings, reaction temperature and S/C ratio on toluene conversion and gas product composition were investigated in a fixed-bed reactor. The catalysts before and after reaction were characterized by XRD, BET and SEM.The experimental results show that RHA as a support of single metal Ni-based catalyst has a certain catalytic activity;The activity and resistance to carbon deposition of Ni/RHA catalyst were significantly improve by that formation of NiMgO solid solution active center after the loading of MgO, and the catalytic activity and the resistance to carbon deposition of Ni/RHA catalyst were optimal when the Mg loading amount was 6wt%, and the toluene conversion was as high as 98.6%;The optimum reaction temperature of 3Ni-6Mg/RHA is 700 ℃, S/C is 3, and the catalyst has good catalytic stability. The feasibility of using rice husk ash as the support of nickel-based catalyst in the presence of MgO was proved.
                                                                                                                         
          Abstract:
          In view of the complex production conditions of heavy soil compaction in the middle and lower reaches of the Yangtze River, large fluctuations in water content, and large remaining rice straw residues, and the production requirements of rapeseed cultivation for rapeseed cultivation, an imitation shoe-shaped ditching plough used in combination with a driven plough combined rotary tiller was developed. According to the principle of the guide curve of the plow body and the modeling analysis of the three-sided wedge, a smooth parabola is selected as the sliding cutting edge curve, and the sliding angle of the sliding cutting edge curve is determined to range from 25 ° to 65 °, and the plough body entry angle is 30°. The opening angle of the plow tip is 60 °. Through the dynamic analysis of the interaction between the shoe-like sharp-angle ditch plow and the soil, the length of the fender is 400mm, and the inclination of the wing is 40 °~79.2 °. Field tests have shown that a shoe-like sharp-angle ditching plough can produce a trapezoidal ditch with a ditch width of 200~400 mm and a ditch depth of 175~250 mm. The ditch width and ditch depth stability are both above 90%, and the ditch bottom is flat. The ditch shape is obvious, when the inclination of the wing is 46 °, the ditch depth is 183mm, and the working speed is 0.6m/s, which meets the agronomic requirements of rapeseed planting, and provides a reference for the equipment design of the furrow ditch for rapeseed bed preparation
                                                                                                                         
          Abstract:
          Public governance in rural environment is a complex negotiation process in which multiple parties are constantly interacting and repeatedly running. The construction of the rural waste sorting mechanism in Zhejiang Province was implemented under the influence of local government administrative orders. In the context of environmental governance, it conformed to the national policy of the country, but it did not necessarily satisfy the “taste” of the farmers. Under the support and guidance of local elites such as village cadres, through the internal organization of the village to guide and innovate ways of management, to promote farmers to gradually develop the habit of garbage classification, and according to the practical experience of rural waste classification to continuously adjust the classification of waste introduced by local governments. The system eventually formed some local waste classification policies and systems that are in line with rural society and have operational abilities. The construction of rural waste sorting mechanism in Zhejiang Province is not only the process of introducing, adapting and perfecting the local social waste sorting mechanism, but also the process of farmers adjusting their behavior and shaping waste sorting behavior under the influence of government classification system and production lifestyle, or local government. The result of the power struggle between the village cadres and the villagers in the village environmental governance and the interests of the game and the final compromise.#$NLKeywords: rural areas; interactive governance; waste classification; mechanism construction; behavior shaping
                                                                                                                         
          Abstract:
          The results of herdsmen's collective development in Tibet depend on ttwo interrelated stages: how are the public resources transferred to pastoral villages, and how are they transformed into herdsmen's endogenous development ability. Based on the analysis framework of "system-life", this paper investigates the phenomenon of herdsmen's collective development in GeJi county. It is found that the herdsmen's collective development is essentially the result of "interactive co-governance" between local government and herdsmen's society. The local government strongly embeds into herdsmen's society through the selection of village cadres and provision of policy projects , and promotes the orderly changes of herdsmen's society within the collective framework on the basis of respecting the livelihood mode of the pastoral areas. The village collective undertakes the government public resources, and adopts the flexible conformity means such as emotion association and benefit association. It guides the herdsmen's collective development from the "system" form to the "entity" form, and effectively realizes the village public reproduction. In the process of herdsmen's collective development, the continuous interaction between system and life enhances the herdsmen's endogenous development capability. The herdsmen see the possibility of solving their own survival crisis, and the consistency of interests arouses the sense of trust and belonging to the collective. The herdsmen's collective development is entering a virtuous cycle.
                                                                                                                         
          Abstract:
          Based on 839 field survey data from Jiangsu Province and Anhui Province, combined with the theory of environmental literacy and the theory of action stage, this paper divides the behavioral intention into two stages: goal intention and execution intention, and analyzes the impact of environmental literacy on consumers' green consumption behavior by using structural equation model. The empirical results show that the four dimensions of environmental literacy, namely, environmental values, environmental responsibility, environmental problem perception and environmental behavior skills, all have an indirect impact on green consumption behavior through green consumption intention, which conforms to the impact mechanism of action stage theory. Among them, environmental values have a significant positive impact on green consumption behavior through green consumption execution intention; environmental responsibility and environmental behavior skills have a positive impact on green consumption behavior through green consumption goal intention and green consumption execution intention, and green consumption goal intention has a significant impact on green consumption execution intention; environmental problem perception has a positive impact on green consumption behavior The impact of green consumption behavior follows the path of "environmental awareness - green consumption goal intention - green consumption execution intention - green consumption behavior", and has a significant negative impact on green consumption behavior. Based on this, in order to further promote green consumption behavior, this paper puts forward corresponding policy recommendations from the government ,enterprises and consumers.
                                                                                                                         
          Abstract:
          In recent years, the extraordinary fluctuations of hog price in China exert adverse effects on people’s livelihood and the development of related industries. Thus, exploring the influencing factors of hog price and obtaining the accurate forecasts of hog price are of great practical significance. In view of the time-varying characteristics of hog price's influencing factors, this paper puts forward an influencing factors analysis and hog price forecasting framework based on dynamic model averaging theory. Specifically, In view of thirteen influencing factors derived from the supply of hog, demand of hog, economics environment of China, and international markets, this paper investigates the time-varying characteristics of influencing factors, and then construct the hog price forecasting model, by introducing the dynamic model averaging. Furthermore, we compare the ability of the proposed model and benchmarks used to forecast the hog price by accuracy measures and DM test. The empirical results indicate that the influencing factors of hog price exhibit significant time-varying characteristics. Since 2009, the decision mechanism and influencing factors of hog price have become more complicated and diverse, respectively. Furthermore, the hog price forecasting model based on dynamic model averaging achieves more accurate forecasts than benchmarks.
                                                                                                                         
          Abstract:
          The project going to the countryside was both a resource to the countryside and a rule to the countryside. The injection of resources and the guidance of the rules have reconstructed the governance order within the village. After the resources went to the countryside, the operation logic of village power and the rules of public interest distribution were changed, and a "power-benefit network" within the village was established. The stably periodic selection of village cadres, the circle of the distribution of benefit opportunities, and the closure of project operations were the external characteristics of the operation of the "power-interest network" within the village. In the "power-benefit network", the relationship network constructed by information sharing, the transfer of interests to promote the operation of the order, and the autonomous order formed by the formalization of responsibility had all caused new changes in the content of village order. The project going to the countryside was a system design to promote village development, the village social order was generated during the project's going to the countryside, but how to build a standardized and effective new order to improve the resource efficiency of the countryside needs further research.
                                                                                                                         
          Abstract:
          The impact of land transfer on farmers" welfare has been studied after confirming the rights of farmland. Taking 440 farmers in Hubei Province as the research object, based on the theory of Sen"s feasible ability, using Logistic model and Propensity Score matching Method (PSM), the welfare factors that affecting farmers" participation in land transfer after confirming the rights of farmland has been analyzed, and the changes of farmers" welfare in land transfer has been measured. The results showed that: (1) after confirming the rights of farmland, the welfare factors that affected farmers" participation in the land transfer were net income of family、medical insurance、 recognition of social security、difficulty of employment、self-assessment of the health status、farmers" right to participate the land transfer and satisfaction with the transfer price. (2) Through measuring the effect of the change, farmers" welfare could been significantly improved by land transfer, the effect value of the change in the welfare of the out- transferred farmers was 1.10, and that of the change in the welfare of in- transferred farmers was 0.793; (3) after confirming the rights of the farmland, the net income of the family, the recognition of the social security of farmers and the self-assessment of the health status could significantly improve the level of farmers" welfare, while the difficulty of employment would hinder the level of farmers" welfare; the satisfaction of land transfer price could improve the welfare of out-transferred farmers, but hinder the welfare improvement of in-transferred farmers. Based on this, relevant policies and recommendations would be proposed to promote the improvement of farmers" welfare in the land transfer after confirming farmland rights.
                                                                                                                         
          Abstract:
          In recent years, the rapid development of China's policy-oriented agricultural insurance is closely related to the strong support of the state finance; using descriptive statistical data to sort out the development trend of China's policy-oriented agricultural insurance since the pilot project in 2007; using comparative analysis methods, selecting the policy-oriented agricultural insurance of the United States, Canada, Japan and other countries for comparison, in-depth analysis of the existing problems and difficulties of China's policy-oriented agricultural insurance under the new situation; The research shows that there is a big gap between the practical development of policy-oriented agricultural insurance and policy expectations, and there are still some problems compared with developed countries: the objectives of agricultural insurance policy do not adapt to the situation of agricultural development, the provincial differences of financial premium subsidies are not obvious, the types of agricultural insurance insurance are relatively single, the number of agricultural products supported by financial support is relatively small, the level of agricultural insurance security is on the low side, and the management of agricultural insurance organizations is relatively backward; Finally, the optimization path of agricultural insurance policy is put forward: to further adjust the goal of agricultural insurance policy, to formulate the policy of differentiated premium subsidy of central finance "according to the province", to carry out complete cost insurance, output insurance and income insurance, to increase the range of agricultural products by financial support, to improve the level of agricultural insurance guarantee, and to construct a national agricultural insurance management system.
                                                                                                                         
          Abstract:
          Farmers’ varieties are cultivated by farmers through collective innovation in certain areas for long time, and are proved to be of special quality, they have collective, territorial and inherited attributes. The value of farmers’ varieties and the core of their protection are genetic information they contain. They are suitable for protection by intellectual property systems, but they should be different from intellectual property systems of protecting private innovation. The acquisition of farmers’ varieties should meet condition of identifiability in less demanding, and go through the registration process. The protection modes of farmers’ varieties mainly include positive protection in form of sui generis right and defensive protection. Under protection of sui generis right, subject of farmers’ varieties right is divided into two levels, static right of farmers’ varieties belongs to the state, dynamic right of farmers’ varieties should exercised by the farmer collective of specific community. Farmers’ varieties right with collective attributes shall not be transferable. But obligee could enjoy the rights of informed consent and benefit sharing based on the permission. Some restricted systems should be set up at the same time, such as rational use, compulsory license and protection time limits, in order to achieve the balance of interests, and promote innovations in plant breeding.
                                                                                                                         
          Abstract:
          In order to promote "indica to japonica" in Hubei Province, Five japonica rice varieties were used as materials, and four sowing dates were set under the condition of machine transplantation to study the yield, growth period, quality, utilization of temperature and light resources of Japonica Rice varieties for clarify the ecological adaptability of different types of Japonica Rice Varieties in different japonica wheat production areas in Hubei Province. The results showed that as the sowing date was postponed, the growth period of the tested varieties was shortened and the growth process was accelerated. Except for Yongyou 4949 in Jiangling, the yield decreased to different degrees, and the utilization rate of effective accumulated temperature and sunshine hours utilization rate showed a downward trend during the whole growth period. According to the conditions of temperature and light resources and the time of wheat stubble removal in the three ecological regions, the suitable japonica rice varieties and sowing dates are preliminarily determined. The suitable japonica rice varieties are early maturing medium japonica rice and medium maturing medium japonica rice with short growth period in Xiangyang. The varieties suitable are early maturing medium japonica and medium maturing medium japonica in Xiaochang. The varieties suitable are early maturing medium japonica, medium maturing medium japonica and early maturing late japonica, which can all exert the best yield potential in Jiangling.
                                                                                                                         
          Abstract:
          Returning home and starting a business is an important way to develop the rural economy and achieve rural rejuvenation. This article uses the data from a nationwide survey of returnee entrepreneurs after the implementation of the rural revitalization strategy, and examines the impact of special trust for relatives on the entire process of returnee entrepreneurship. The study found that special trust will enable entrepreneurs to start businesses based on developmental motivations, but will inhibit them from obtaining policy information and labor through formal channels, and will not promote objective economic performance. Therefore, on the basis of encouraging returnee entrepreneurs to give play to the positive impact of special trust in the initial stage of entrepreneurship, the relevant departments should actively promote the connection between preferential policies and entrepreneurs and strengthen the ability to implement policies to improve returnee entrepreneurship Economic performance.
                                                                                                                         
          Abstract:
          Traditional theories in agricultural economics generally assume there is a constant return to scale in agriculture. Such an assumption is not only inconsistent with the concept of the endogenous technical change and the “learn by doing” models in neoclassical economics, but also can’t explain the agricultural growth caused by the intensive and meticulous farming practices in traditional peasant economy and the division of labor in modern agriculture. By expanding the “learn by doing” models developed by Arrow (1962) and Yang and Ng (1993), we analyzes how farmers can exercise their “learning by doing” to achieving the increasing return to scale by adjusting the planting structure and agricultural inputs in a traditional peasant economy and an era of agricultural division of labor without account of external technical change. The analytical results indicate that (1) without rigid constraint in agricultural labor, the “learning by doing” will improve labor productivity and increase return to scale through the expansion in the farming scale by renting more farmland or the increases in cropping index to fully use the excessive agricultural labor; (2) with rigid constraint in agricultural labor due to the labor migration from agricultural to non-agricultural sectors, the return to scale in agriculture can become decreasing after the increase induced by the learning by doing; (3) the division of labor in agriculture helps overcome the rigid constraint of agricultural labor and stimulates labor specialization and “learning by doing” that lead to the increasing return to scale in agriculture. The findings show that agriculture has never been a passive industry with low efficiency, but evolving industry with constant pursue of efficiency and growth.
                                                                                                                         
          Abstract:
          Based on the survey data of 25 provinces in China, this paper explores the mechanism of property security and property rights cognition on the inconsistent of land transfer intention and behavior by using Probit model and Tobit model. The empirical results show that there are conditions for the transformation of land transfer intention to behavior. When the stability of land rights is high, the farmers' land transfer intention can be transformed into behavior easily, otherwise it can't. Farmland right confirmation makes the land property rights of farmers more clear, and then by reducing transaction costs and increasing land rent, it can ultimately promote the transformation between farmers' intention and behavior to transfer in and hinder the transformation between farmers' intention and behavior to transfer out. At the same time, the village control also has the same effect as farmland right confirmation. Therefore, on the basis of maintaining the stability of land property rights, the market of land management rights should be standardized. Beyond that in order to create favorable conditions for farmers to participate in the land transfer market, the advantages of village committee in organizing land transfer should be brought into play.
                                                                                                                         
          Abstract:
          To scientifically analyze income changes of farmers’ households after land transfer, this paper explains incentives of decision-making behavior of farmers’ land transfer by micro-economics models, then uses Logistic to analyze influencing factors of farmers’ decision on land transfer and uses Propensity Score Matching to test income effect based on rural household’s data from survey in the eastern part of Hubei province. The results imply that :(1) Education level, land management area, number of agriculural labor force, policy cognition and property right cognition have a significant positive impact on farmers' decision on land flow in. Age of household heads, management type, endowment insurance and policy cognition are the main incentives for farmers to low out land and engage in off-farm activities. (2) Land flow in or out is beneficial to raise farmers’ household income since the income growth rate of land flow-in farmers and land flow-out farmers is 12.74% and 7.57% compared with land non-flow farmers respectively. (3) There are significant structural differences in the income growth effect between land flow in farmers and land flow out farmers. The former contribution rates of operating income, wage income, transfer income and property income to household income increasing are 62.87%, 26.24%, 9.05% and 1.84%, and the latter contribution rates are 52.41%, 88.69%, 25.09% and 40.33% respectively. Finally, some policy suggestions are put forward, such as cultivating new-type agricultural businesses and adopting new transfer pattern to promote the efficiency of agricultural production, as well as further reforming land tenure policy and broadening channel for non-agricultural employment to smoothly transfer rural land and surplus labor force.
                                                                                                                         
          Abstract:
          Based on the evolution trend and current situation of the state-owned farmland system, this paper constructs the improvement scheme of the state-owned farmland system, to satisfy the practical needs of the state-owned farms and farmers. On the basis of state-owned land, land use right can be defined as property right, to promoted the paid use of agricultural land use right steadily. On the basis of the two-field system, the land management right in the basic fields should be modeled as usufructuary property right. And the land management right in the large-scale fields can be set up according to the logic of right and obligation right dichotomy. The long-term land management right is created as real right, and coordinated according to the property law. While the short-term management right is coordinated according to the principle of freedom of contract. In the process of land legislation, two different types of norms should be integrated to distinguish the real rights of state-owned agricultural land from the obligation rights.
                                                                                                                         
          Abstract:
          Farmers' urban settlement decision is not only influenced by their own conditions, but also constrained by the settlement policy.In the rural land contract law of China in 2019, the article on settling down is amended to read "no withdrawal from collective land is allowed as a condition for settling down in cities". Whether the policy adjustment can promote the development of urbanization in China, this paper USES 484 questionnaires of rural households to discuss this issue.The results show that the modification of the contract law has improved the willingness of farmers to settle down in cities, and 26.3% of them are willing to settle down in cities instead of in cities.Rural households with educational needs are more likely to be released by the policy.In addition, households with strong urban viability and a high degree of tolerance to the outside world are more likely to change their intention to settle down in this policy change.The research further shows that after the modification of the contract law, cities not only need to expand their capacity in stages, but also need to pay more attention to the correlation between education and employment.
                                                                                                                         
          Abstract:
          The aging of agricultural transfer is an important feature of rural labor migration. we construct a two-sector model to study the migration decision of the young labor force and the old-age labor force from the perspective of labor efficiency and explain this phenomenon. Besides, this paper theoretically obtains the two-stage characteristics of labor transfer. Based on census data, this paper first calculated the number of laborers of all ages who moved from agriculture to non-agriculture in the four time periods 1995-2000, 2000-2005, 2005-2010, and 2010-2015. The two-stage migration of rural labor is characterized by the fact that the young laborers in the initial period flowed out of agriculture, and it was difficult for the old-aged labor force to flow out; in the later period the young laborers began to return to agriculture, and the older laborers flowed out of agriculture. This conclusion shows that the benefit of allocating different age group laborers between agriculture and non-agriculture still exists. We hold the opinion that promoting the reform of the household registration system and the land system and facilitating the free flow of the labor force can better take advantage of this benefit and revitalize the countryside.
                                                                                                                         
          Abstract:
          Base on the data from the China Longitudinal Ageing Social Survey conducted in 2014, using Latent Class Analysis, this study analyzed the urban-rural differences in the types of intergenerational relations from a whole family perspective. We found three types of intergenerational relations: tight-knit, support but distant, and detached. Among these types, the first two accounted for a larger proportion, and the last accounted for a small proportion, which revealed that the intergenerational relations of Chinese families are still dominated by solidarity. The common characteristic of the three types was that children have provided with high-frequency financial and emotional support for parents, and the discordant parts in the type of “support but distant” and “detached” are both caused by the space barrier between generations, which indicated that families still maintain the function of old-age support, but accompanied with the obvious feature of geographical distant between generations. The relationship types have significant urban-rural differences, urban areas dominated by the type of tight-knit, and rural areas dominated by the type of support but distant, which reflected the background of population migration in China. The types of intergenerational relations in urban and rural areas both embodied the model of corporate group between generations, that is, intergenerational support always flows to the relatively vulnerable family members. Our results showed that the disabled or oldest old are unlikely to form the detached structure with their children. The types of intergenerational relations in rural areas highlighted the model of power and bargaining between generations, that is the old adult with more resources are more likely to get support and attention from their children. We found that urban older adults with higher incomes can help them form a tight-knit structure with their children.
                                                                                                                         
          Abstract:
          effective measurement of the effect of agricultural subsidies on household income is an important issue in evaluating agricultural policies and implementing targeted poverty alleviation. This paper theoretically demonstrated the effect of agricultural subsidies on income increase and the mechanism of the impact of agricultural subsidies on farmers" income heterogeneity, and then use the data of Chinese Household Finance Survey (CHFS) in 2015 to verify the theoretical hypothesis . Based on instrumental variable quantile regression, it finds that : (1) there are differences in the impact of agricultural subsidies on the income of farmers at different income levels. Agricultural subsidy can significantly promote the increase of low-income farmers" income, but has no significant impact on the income of high-income farmers. (2) there is regional heterogeneity in the impact of agricultural subsidies on household income. Agricultural subsidies can significantly promote the increase of farmers" income in the eastern and western regions, but have no significant impact on the central region. (3) agricultural subsidies can alleviate the income inequality of farmers at different income levels. (4) agricultural subsidies alleviate the income inequality of farmers in the central and western regions, but aggravate the income inequality of farmers in the eastern and central regions. The study of this paper provides favorable theoretical and empirical support for the government to carry out precise subsidy.
                                                                                                                         
          Abstract:
          The “Red Line of Ecological Protection” is an institutional innovation in China's ecological environment protection. Delineating the red line of ecological protection to meet the needs of China's development and environmental management is an important practice in the construction of ecological civilization at this stage. However, the red line system of ecological protection cannot stay at the level of policy guidance, and its authority must rely on legislation to create guarantees; only if its policy concepts and regulatory requirements are raised to the level of legislation, it can effectively provide for the implementation of ecosystem protection planning and ecological bottom line maintenance. Guarantee. The practice or legislative exploration of the red line regulation of ecological protection shows that the legislative basis and normative system are becoming clearer, and it is urgent to improve relevant legislation, to build a legal framework for ecological red line management, and to promote the ecological protection red line system to be consistently “landed”. The single-line law, relevant legislation, especially local legislation, is clarified. Implementing the red line legislative concept of ecological protection is the core requirement of the legalization of ecological protection in China at present. In addition to policy direction and relevant legislation and regulation, it must be supported by a series of supporting mechanisms and implementation measures.
                                                                                                                         
          Abstract:
          Customers often react strongly to service failure, understanding consumers’ responses to different types e-service failure is an key prerequisite for agricultural e-commerce companies to address service failures and seek long-term development. In this article, based on the definition of e-service quality, the authors divide e-service failure of agricultural product into four categories: fulfillment, website design, privacy and security, and customer service, exploring the mechanism of consumers’ response to e-service failures of agricultural products based on an exchange framework, using the between-subjects experiment design to test the hypothesis. According to the results, different types of agricultural product e-service failures have different negative effects on consumers’ repurchase intention. Furthermore, this study also finds that consumer’ perceived justice mediates the negative effect of agricultural e-service the failures on consumers’ repurchase intention. In addition, this study also finds that different types of agricultural product e-service failures have different negative effects on the specific dimensions of perceived justice. These findings provide important implications for agricultural e-commerce companies to effectively handle service failures.
                                                                                                                         
          Abstract:
          Optimizing the allocation of agricultural resources plays an important role in promoting the growth of agricultural productivity. Based on 1384 county-level panel data from 2002 to 2015, this paper estimates the resource reallocation and its productivity contribution by OP decomposition taking labor productivity, land productivity and total factor productivity as examples. The results show that;① Overall, the reallocation of land factors and labor factors are both relatively lagging, and the comprehensive resource reallocation is continuously optimized. ② From the perspective of sample distribution, the efficient reallocation of labor, land and total factors in northeast region is relatively lagging. ③ From the perspective of productivity effect, the optimal reallocation of labor factors can increase labor productivity by 54.64%, and the optimal reallocation of land factors can increase land productivity by 55.86%, and resource reallocation contributes 17.37% of total factor productivity growth. The resource reallocation has a large potential productivity effect. Therefore, the resource reallocation should gain more attention when putting forward agricultural policy, especially for the reallocation of land and labor, to make full use of the productivity effect of resource reallocation.
                                                                                                                         
          Abstract:
          In order to solve the problem of severe vibration caused by fruit tea garden conveyer in practical use, a semi-active suspension system using CDC damper was designed, and the loading test was carried out by using fuzzy PID control method. According to the suspension system dynamics model, MATLAB was used to establish a Simulink model of fuzzy PID controller, which was analyzed and the parameters were adjusted, and the ideal simulation response results were obtained. Through the analysis, the performance of semi-active suspension system was improved by 10% ~ 20% compared with that of passive suspension system. Design of hardware part of the semi-active suspension system and loading test, the system of mechanical parts including the elastic element structure, shock absorber, steering mechanism, and the parts fitting the transformation, consider front axle layout space arrangement, the shock absorber system layout in the form of oblique arranged with the horizontal plane Angle of 30 °, elastic element for vertical layout, steering mechanism installed in the middle of the front axle position, to limit the movement before and after the front axle and constraint the trajectories of vertical direction. According to the design of fuzzy PID controller for the design of control circuit system, the semi-active suspension loading experiment was carried out, using vibration meter and vibration sensor system is built, the test vehicle in the process of driving seat position z axis vibration signal, respectively in speed and load conditions, through the semi-active suspension before and after loading, the results of test of conveyor with semi-active suspension vibration drop of about 50%, reached the design requirements of the semi-active suspension system.The vibration frequency concentration range of the vehicle body with semi-active suspension system is more than 8Hz, indicating that the driving comfort of the vehicle is better.
                                                                                                                         
          Abstract:
          It is an important part of the performance evaluation of poverty alleviation policies that research about the impact of poverty alleviation policies on the high-quality growth of agricultural economy. Based on the released list of counties and cities in concentrated and contiguous poverty-stricken areas in 2012, this paper takes whether they are included in the list as the identification variable of the inclined support policy, and uses the data of 86 counties and cities in Gansu province from 2009 to 2016 and the DID method for empirical analysis. We found that poverty alleviation policy has a significant positive effect on agricultural economic growth in concentrated and contiguous poverty-stricken areas, however, it has no significant impact on agricultural industrial structure and agricultural technical efficiency. The poverty alleviation policies have achieved remarkable results in supporting deeply impoverished counties, and the policy performance in arid areas and poverty-stricken counties inhabited by ethnic minorities is better than that in humid areas and poverty-stricken counties inhabited by non-ethnic minorities. At the same time, with the continuous implementation of the preferential support policy, the poverty alleviation policy plays an increasingly strong role in promoting the agricultural economy. Overall, poverty alleviation policies have not effectively promotes high-quality growth of agricultural economy.
                                                                                                                         
          Abstract:
          The credit market participation of rural households in poor areas is an important factor affecting the effect of credit poverty alleviation. Based on the theory of local knowledge, this paper constructs an analysis framework of rural households" credit market participation in poor areas in the aspects of credit concept, wealth cognition and life logic, and takes the empirical data of Inner Mongolia and Shandong province as evidence. The research shows that local knowledge of lending, as a financial and cultural background factor that affects rural households" production and life, has a potential role in regulating and guiding rural households" participation in the credit market in poor areas. The credit market participation behaviors of rural households show external consistency in the same region, while there are obvious differences among different regions. Therefore, in the context of the targeted poverty alleviation policy that emphasizes helping villages and households, attention should be paid to the collective and regional characteristics of rural households" credit needs in poor areas, and credit poverty alleviation tools should be innovated according to the time, place and individual conditions.
                                                                                                                         
          Abstract:
          In view of the large labor intensity of the excavation machinery in the existing mountain tea orchard, an electric self-propelled digger with driving power and automatic feed stroke and reset stroke was designed. In this paper, the digger is divided into five parts: the burrowing mechanism, the automatic lifting mechanism, the travelling mechanism, the supporting mechanism and the control system, meanwhile, the design and selection of the key components and the prototype manufacturing and assembly was completed. According to the field test results, the average burrowing time for a single operation of the digger was 50.7 s, the energy consumption for a single effective burrowing operation was 6.38 Wh, the average depth of the hole was 392.5 mm, the average hole diameter is 303 mm, and the orchard road speed was 1.237 m/s, the mud road speed was 1.202 m/s, and it can smoothly passed the 15° slope. In the burrowing operation, the feed and return movements do not require manual operation, which can reduce the labor intensity.
                                                                                                                         
          Abstract:
          Physical and mechanical characteristic parameters are indispensable in the design of potato minituber related mechanical equipment planter and classifier, developing of simulation technology the contact mechanics parameters are also. Aiming at these problems, "Daxiyang", "Zhongshu No. 5" and "Huashu No. 1" were taken as research objects. The Physical mechanics parameters and contact mechanics parameters were determined with the relevant parameters required for discrete element software EDEM in potato minituber research. The parameters measured in the above experiment were input into the EDEM for simulation to obtain the rolling friction coefficient between the potato minituber. the stacking angle was used as the response value, and the credibility of the simulation results was verified by raising a round pipe slowly. The results show that compared with the actual accumulation angle of the experiment, the simulation results of different varieties of potato minituber are less than 3%, and the results are reliable.
                                                                                                                         
          Abstract:
          Risk is inherent part of agriculture and thus unifying households’ risk management willingness with their adoption is the crucial way to reduce the negative influence of agriculture risk. Collecting data from the Large-Scale farmers in the Northeast China. and Hubei province in 2018, this study focuses on farmers’ risk management willingness, adoption and the paradox of them from the perspective of natural risk and market risk. Furthermore, we explore the reason of the paradox of willingness with adoption. The empirical results show that most of farmers have adopted management strategy for natural risk, but they have lower risk management willingness. The adoption for market risk is extremely scarce. Ironically, farmers usually have higher risk management willingness for market risk. The results shows that implementation intentions of risk management, actual behavioral control of risk management and situational context of risk management, understanding of agricultural insurance and disadvantages of agricultural insurance are the primary causes of the paradox of management willingness with adoption for natural risk. We found that the main reason lead to the paradox of management willingness with adoption for market risk is the lack of publicity and information channel for risk management strategy, leading to farmers’ incomprehension and misunderstand with risk management strategy. In order to unify farmers’ risk management willingness with their adoption, we need strengthen government publicity and guidance for market risk management, improve the mechanism for popularizing agricultural insurance, expand trials of insurance plus futures.
                                                                                                                         
          Abstract:
          Aiming at the safety problem caused by random rope and extruded rope when the rope is used on the curved and undulating track, a kind of self-propelled electric double-track conveyor without wire rope is designed. Conveyor is mainly composed of electric driving system and transmission system, light quality, the ground target load and the maximum slope load design value of 75 kg, 175 kg, 75 kg, the maximum slope gradient is 30 °.The mechanical model of the conveyor was analyzed, and the motor and battery parameters were obtained. The selected driving motor model was Santuo GW114165.Through the finite element analysis of rubber wheel, it is shown that both the driving wheel and the supporting wheel meet the design requirements. The current test shows that under the conditions of different loads and different slopes, the variation range of power supply current and motor current of the conveyor is 2.61~ 20.12a and 1.305~ 10.06a respectively. The selected motors and batteries meet the design requirements, and the running speed of the conveyor is 0.241~0.7m/s. The flat land energy consumption test shows that the same load has a small variance, indicating that the energy consumption of the transport plane is relatively stable under the same working condition. The energy consumption is maintained at 1.58-2.88w h under different loadings. According to the battery pack capacity of 576W?h, the range of the flat land of the transport plane is calculated to be between 3560m and 6489.1m.The skidding test shows that it is best not to stop the machine at the steep slope under full load climbing state. If the machine needs to stop, it can be started manually. The orthogonal test shows that the driving wheel material, the rail slope and the loading quality have different influences on the operation speed of the conveyor. The influences of each factor on the operation speed are B>A>C, and the Sig value of the slope on the operation speed is 0.049, less than 0.05, which has the most significant influence. Therefore, in order to improve the operation speed of the conveyor, the rail slope can be taken as the entry point to reduce the slope as far as possible, so as to improve the operation speed of the conveyor. Therefore, this study can better solve the safety problems caused by random rope and rope extrusion when the traction steel wire rope of the wire rope traction type double-rail transport plane works on the curved and undulating track, and provide a reference for the follow-up development of the self-propelled double-rail transport plane in the mountainous area.
          Display Method:
          2015,34(4):108-113, DOI:
          [Abstract] (1505) [HTML] (0) [PDF 1.06 M] (8580)
          Abstract:
          In this study,we investigated the effect of bio-floating bed on growth and muscle quality of grass carp (Ctenopharyngodon idellus) and blunt snout bream(Megalobrama amblycephala) in ponds.Two modes of culture ponds were chosen:one equipped with bio-floating bed was the experimental pond,and the other without beds was the control pond.At the end of the experiment,we measured the growth parameters,the muscle conventional nutrients,water holding capacity (WHC),and texture characteristics using biochemical and physical methods.The results showed that the final weight of fish cultured in the experimental pond was higher than that in the control pond.The hepatic somatic index of grass carp (1.77%) in the experimental pond was significantly lower than that of the control (2.47%).The condition factors of grass carp and blunt snout bream (1.73 and 2.56,respectively) were significantly higher than those of the control (1.64 and 2.40,respectively).There was no significant difference in the eviscerated weight of both carp and bream between the experimental (91.06 and 88.28,respectively) and the control (89.22 and 88.49,respectively) ponds.The drop loss (14.49% and 10.69,respectively) and water loss rate (17.52% and 10.34%,respectively) of the experimental grass carp and blunt snout bream were significantly lower than those of the control.The cooked rate of the experimental fish was significantly higher than the control.The muscle crude fat content (1.89%) and crude protein content (14.60%) of grass carp in the experimental ponds were significantly higher than those of the control (1.54% and 13.46%),whereas muscle water content (81.68%) of the experimental fish was significantly lower than that (82.65%) of the control.There is no significant difference in muscle ash content between the two groups.Unlike grass carp,only muscle crude protein content (17.23%) of the experimental bream was significantly higher than that (15.90%) of the control.The muscular hardness,gumminess,and chewiness of the experimental carp (5 298.10 g,2 450.78 g and 770.78 g,respectively) were significantly higher than those of the control (3 226.79 g,1 881.43 g and 602.80 g,respectively).The resilience (0.31) and cohesion (0.48) of experimental carp were significantly lower than those (0.43 and 0.58,respectively) of the control.However,only the muscular springiness of the blunt snout bream in the experimental pond was significantly higher than that in the control pond.
          2015,34(4):120-124, DOI:
          [Abstract] (1840) [HTML] (0) [PDF 976.50 K] (6604)
          Abstract:
          Effects of soaking temperature,cultivation temperature and watering frequency on the growth characteristics and nutrition of mung bean sprout were investigated. Growth characteristics and nutrition of mung bean sprout were significantly affected by soaking temperature,cultivation temperature and watering frequency (P<0.05). When the bean was soaked at higher temperature (40℃),body weight of the cultivated mung bean sprout was heavier,hypocotyl was longer,contents of free amino acid (FAA),water soluble sugar (WSS) and γ-aminobutyric acid (GABA) were higher. The hypocotyl was longer while the diameter was smaller when the bean was cultivated in the relatively higher temperature (30-35℃). When the watering frequency decreased,weight,hypocotyl length and diameter decreased,WSS content decreased first and then increased,FAA content increased first and then decreased,GABA content was fluctuated. The optimal germination conditions of mung bean sprout were soaking bean at 40℃ for 5 h,with cultivation temperature of 25-30℃ and watering once per hour.
          2013,32(4):48-54, DOI: 1000-2421(2013)04-0048-07
          [Abstract] (1743) [HTML] (0) [PDF 1.58 M] (5195)
          Abstract:
          The spatial distribution of Valley County land use degree in 2009 was studied and the spatial autocorrelation of land use degree and its driving factors in different scales were analyzed.A spatial autoregressive model and geographically weighted regression model was established from the perspective of global local.The results showed that there was a certain spatial autocorrelation in land use degree and its driving factors with scale effect.Spatial regression model could estimate the overall parameter of various factors while geographically weighted regression model could give the local parameter of various factors.Scales of geographical weighted regression model could reflect the detailed geographical information to some extent.
          2015,34(1):128-135, DOI:
          [Abstract] (1981) [HTML] (0) [PDF 1.21 M] (4067)
          Abstract:
          In order to overcome the transition,field operation, and standardized batch production difficulties of the existing track cargo vehicle in mountainous orchard, as well as to raise the utilization rate, the mountain orchard detachable unidirectional traction double track cargo vehicle was developed. This paper introduced the whole machine structure, the wire rope diameter selection,the minimum track inclination,the maximum track distance,the minimum track turning radius and the working principle of the rope brake device. Load experiments were carried out to test the cargo′s synthetic track function. It is indicated by calculation that the wire rope diameter should be 7.7 mm,the minimum track inclination was 5.7°, the maximum track distance was 170 m, the minimum track horizontal turning radius was 7 m, and the minimum track vertical turning radius was 2 m. Load experiment results indicated that the cargo vehicle′s uplink average speed was 0.51 m/s, the downlink average speed was 0.54 m/s, the average energy consumption was 1.235 kW·h and the effective use degree was 100%. This cargo vehicle was suitable for fruit, pesticide, chemical fertilizer and other cargo transportation in the mountain orchard. Meanwhile, it can be applied to carry the spraying machine, the shave machine and other agricultural machines.
          2012,31(1):16-22, DOI: 1000-2421(2012)01-0016-07
          [Abstract] (2264) [HTML] (0) [PDF 1.07 M] (4006)
          Abstract:
          Nitrogen is one of essential nutrients for plant growth.Under the N deficiency at different time points,the dynamic changes of the expression of genes and activity of enzymes related to nitrogen assimilation in rice were investigated.The results showed that the concentrations of ammonium and nitrate significantly reduced under the N deficiency.Under the N deficiency for a short time,the expression level of genes including NR1, NR2, NiR2,GS2,Fd-GOGAT,GDH2,GDH3 in the shoots as well as NR1,NR2,GDH4 in the roots were up-regulated,and then their expression level decreased after a long time under the N deficiency.Along with the extension of time under the N deficiency,the GS,Fd-GOGAT activities in whole plants,NR activity in shoots and NADH-GOGAT activity in roots decreased while the NADPH-GDH activity in shoots increased.In roots the activities of NR,GDH increased at first and then decreased,while in shoots the NiR activity was just the opposite.Re-supplied N after 7 days of N deficiency,the transcriptional expression level and enzyme activities of NR,NiR,GS,GOGAT,GDH restored,and expression level of some genes increased as well.
          2013,32(5):124-133, DOI: 1000-2421(2013)05-0124-10
          [Abstract] (1365) [HTML] (0) [PDF 4.01 M] (3844)
          Abstract:
          Bacterial canker is a devastating disease of kiwifruit. In recent years,the disease is showing a tendency to outbreak in such countries as Italy and New Zealand,where kiwifruit is a major crop,and has the trends to further spread worldwide,which will be a serious threat to the development of the kiwifruit industry. Based on the latest research reports, this paper summarized the symptoms,pathogen identification,rapid detection methods,virulence differences,infected mechanism,epidemiology and control technology of the disease. Meanwhile,the future research prospect of kiwifruit bacterial canker was also discussed in order to reduce the loss and risk of the kiwifruit industry.
          2015,34(3):8-12, DOI:
          [Abstract] (1083) [HTML] (0) [PDF 3.41 M] (3608)
          Abstract:
          pCB302-3 is a plant mini-binary stable transformation vector.To investigate the transient expression of pCB302-3 vector in plant,GFP was inserted into pCB302-3 vector as a reporter gene,and various factors including density of Agrobacterium cell,supplementation of gene silencing suppression p19 and days post infiltration were optimized based on agroinfiltration method in Nicotiana benthamiana leaves.Results showed that high levels of GFP expression were observed in N.benthamiana leaves 3-5 d after infiltration by Agrobacterium cell suspension contained pCB302-3-GFP with an optical density (D600) of 0.8-1.0 co-infiltrated with p19 gene.
          2012,31(1):127-132, DOI: 1000-2421(2012)01-0127-06
          [Abstract] (1496) [HTML] (0) [PDF 930.13 K] (3542)
          Abstract:
          Post-harvest strawberries are susceptible to the decay of fruit and deterioration of quality due to pathogenic fungi infections,a main factor leading to economic losses for both growers and retailers.With the increase of strawberries planting in China,it is urgent to effectively reduce post-harvest rots of strawberry fruits.In this review,new management developments for controlling fungal diseases in post-harvest strawberry were summarized in terms of physical,chemical and biological approaches,which can help to extend the on-shelf time of strawberry fruits.
          2012,31(5):569-573, DOI: 1000-2421(2012)05-0569-05
          [Abstract] (1163) [HTML] (0) [PDF 912.59 K] (3343)
          Abstract:
          Hydroponic experiments of strawberry were conducted with three formulations of nutrient solution to select the best formulations for soilless cultivation of strawberry.Several main characteristics of growth including the fresh weight and dry weight of overground plant and root,the growth of crown,the photosynthetic and quality of strawberry,the diameter of staminate flower,the growth amass were investigated.The results showed that the effect of nutrient solution with the content of calcium nitrate tetrahydrate,potassium nitrate,ammonium dihydrogen phosphate,magnesium sulfate and ammonium nitrate at 295,303,62,246,0 mg/L on the growing status and fruit quality of strawberry are better than that of the other 2 treatments.This nutrient solution formula was the most propitious for the growth of ‘Jingyao’ strawberry and the enhancement of the fruit quality among the three different treatnments.That is,it facilitated the growth of strawberry in alimentation growth periods,and the leaves of ‘Jingyao’ strawberry was larger and thicker with a dark-green color,and the diameter of the pedicel was also larger. In addition,the nutrient solution formula was also conducive to the flowering promotion and the reproductive growth of strawberry,and resultes showed that the single fruit weight,yield and fruit quality is the best comparing to the other treatments.The results of this study provided academic and technological basis for establishing high yield and quality of strawberry in greenhouse substrate culture of irrigation and nitrogen application system. 
          2016,35(1):81-85, DOI:
          Abstract:
          Using Mesorhizobium sp.S-15 and Paenibacillus sp.S-17 as experimental strains.After cell disruption,NH4OAc extraction,H2O2 solution digestion or without any pre-treatment,K+ content in the fermentation broth of potassium solubilizing bacteria was determined with flame photometer.The efficiency of K solubilizing by potassium solubilizing bacteria in the culture medium was calculated.The results showed that the standard curves of the three kinds of K series of standard solutions were similar with the R2 values of 0.994 4,0.999 7 and 0.999 8,respectively.After digested by H2O2 solution,concentration of K+ was detected.The efficiency of two strains was 101.1% and 125.1%,significantly higher than that of other groups.The efficiency of potassium solubilizing detected after H2O2 digestion well reflected potassium solubilization of bacteria.
          2014,33(01):12-17, DOI: 1000-2421(2014)01-0012-06
          [Abstract] (1494) [HTML] (0) [PDF 944.55 K] (3151)
          Abstract:
          Seventeen pairs of SSR primers with clear polymorphic bands were screened from 60 pairs of SSR locus covering 17 linkage groups of pear genetic map and amplified with 20 pear cultivars.136 polymorphic bands in total were obtained with 5~11 bands per primer locus (8.0 bands on average).The polymorphism information content (PIC) of the 17 SSR loci ranged from 0.614 to 0.848 with an average of 0.733.All pear cultivars studied could be identified with 38 different combinations of 2 markers each.Bands amplified by each marker were coded based on size of fragment and used as a molecular ID.
          2010,29(3):363-368, DOI: 1000-2421(2010)03-0363-06
          [Abstract] (2484) [HTML] (0) [PDF 11.41 M] (3136)
          Abstract:
          The index of heat injury and leaf anatomical structure under the scanning electron microscope of six Primula species were measured to study the responsive mechanism of Primula to the high temperature and to select the heat resistant Primula species.The results showed that Primula forrestii and P.malacoides franch had higher heat-resistance than that of P.obconica,P.veris,P.saxatilis,P.denticulatess.,P.sinodenticulata with lowest heat-resistance.Leaf anatomical structures of Primula associated with heat-resistance included leaf thickness,tightness of mesophyll cell arrangement,the number of open stomata,the number of epidermal hair and powders of leaves.
          2014,33(06), DOI:
          [Abstract] (751) [HTML] (0) [PDF 8.30 M] (3109)
          Abstract:
          The development of Golden Rice to date has taken longer than anticipated.It has been proven to have the potential to assist in the alleviation of an important public health problem,vitamin A deficiency,affecting millions.Complying with the highly precautionary,and now proven unnecessary,UN Cartagena Protocol for Biosafety has impeded scientific progress and scientific collaboration,particularly by delaying the selection of phenotypes grown in the open field.So far therefore,Golden Rice has not been able to assist in combatting vitamin A deficiency,identified by the UN as an important public health target for 25 years,and which continues to cause preventable deaths and blindness.However,the inventor’s original vision of the donation of the technology to assist the resource poor who want to benefit from it remains firm and achievable,subject to continuing philanthropic and public sector funding.
          2014,33(2):139-144, DOI: 1000-2421(2014)02-0139-06
          [Abstract] (1276) [HTML] (0) [PDF 968.56 K] (3101)
          Abstract:
          Algae are lower photosynthetic autotrophs which have close relationship with agricultural activities.With the deep understanding of physiological and ecological characteristics,algae have used more and more widelyin the practice of agricultural activities.This paper reviews the application of algaeas a resourcein agricultural activities including improvement of agricultural environment,utilized as food or food additives and health care products,as well as feed or bait.
          2014,33(2):15-21, DOI: 1000-2421(2014)02-0015-07
          [Abstract] (1702) [HTML] (0) [PDF 980.62 K] (3099)
          Abstract:
          Teosinte is the ancestor of maize,and plays an important role in maize domestication process and gene cloning.Solexa RNA-Seq was used to de novo assembly and analyze the transcriptome of teosintes.40.6 GB raw data were produced,including 175 101 250 reads of 76 bp length.After quality control and de novo assembly,58 147 teosinte transcripts with an average length of 1 335 bp were obtained.After bioinformatically comparing,it was found that 94.3% of teosinte transcripts had good matching with B73 cDNAs,and that 84.1% of the transcript had good matching with rice,84.6% with sorghum and 83.9% with brachypodium at protein level.This research will provide a reference for subsequent studies on maize evolution and gene discovery.
          2014,33(2):96-102, DOI: 1000-2421(2014)02-0096-07
          Abstract:
          A 90-day study was conducted to investigate effects of dietary lipid levels on performance,fat deposition,activity and expression of lipoprotein lipase (LPL) in GIFT tilapia (Oreochromis niloticus) juvenile,and to explore the correlation between LPL gene expression and fat deposition.315 GIFT tilapia juveniles(average weight 2.63±0.16 g) were randomly divided into three groups with three replications,and fed with isonitrogenous diets with different lipid levels of 3.7% (low-lipid group),7.7%(middle-lipid group)and 16.6% (high-lipid group) by supplementing with 2%,6% and 15% fish oil as lipid source,respectively.The results showed:(1) the hepatosomatic index (HSI),viscerosomatic index (VSI) and lipid contents in liver and muscle increased with increasing dietary lipid level(P<0.05),but there was a trends for condition factor (CF) with first increased then decreased (P>0.05); (2)with increasing dietary lipid levels, the weight gain (WG) first increased, then decreased, and feed conversion ratio (FCR) decreased(P<0.05); (3)LPL gene was expressed in liver and muscle of GIFT tilapia,while the expression level in liver was significantly higher than that in muscle (P<0.05); (4) during the 48 h post-refeeding period,liver LPL activity in high-lipid group was significantly higher than that in low-lipid and middle-lipid group at 6 h,but significantly lower than that in low-lipid group at the 12 h,24 h and 48 h.There was a trend in low-lipid and middle-lipid group that liver LPL activity increased first and then decreased; (5) the expression of LPL was significantly higher in high-lipid group than that in low-lipid group (P<0.05); (6) there were a significant linear positive correlation between HSI,lipid contents in liver and muscle,and liver LPL expression in GIFT tilapia juvenile.The results indicated that LPL expression in GIFT tilapia was in a tissue specific pattern and liver was the main organ for secretion and expression of LPL; high dietary lipid level could inhibit growth of GIFT tilapia juvenile,decrease feed conversion ratio,induce the expression of LPL in liver,and promote fat deposition in liver and muscle; liver LPL expression was involved in fat deposition of GIFT tilapia juvenile.
          2015,34(3):134-141, DOI:
          [Abstract] (1138) [HTML] (0) [PDF 1.42 M] (3029)
          Abstract:
          Soil salinity is a major environmental constraint to agricultural productivity.It is a complex network for plant adaptation to salt stress,and it is still a great challenge to improve crop salt tolerance.Mechanisms of SOS signal transduction pathway on Na+ exclusion and compartmentation,the regulation of microRNA and transcription factors involved in salt stress were reviewed.It will provide a fundamental understanding and knowledge for studying salt resistance and breeding salt tolerance in plants.
          2010,29(6):798-804, DOI: 1000-2421(2010)06-0798-07
          Abstract:
          The cracking of fruit skin and the splitting of underlying flesh is a kind of fruit physiological disorder,which downgrades the fruit appearance quality and causes the infection of disease,thereby reducing the commercial value and resulting in serious economic loss.Herein recent studies on fruit cracking were reviewed,mainly focusing on the influence of phenotypic characteristics,genetic factor,physiological characters,mineral nutrients,environmental conditions,plant growth regulators and cultivation practices.The prospect of research was discussed.
          2011,30(2):249-259, DOI: 1000-2421(2011)02-0249-11
          [Abstract] (1050) [HTML] (0) [PDF 1.05 M] (2976)
          Abstract:
          Chloroplast transformation in plants has many advantages over nuclear transformation.Proteins in chloroplasts can be expressed at high levels with proper folding and disulfide bonds as the cells of higher plants contain a large number of chloroplast genomes.Multiple genes can be co-expressed in chloroplast genomes.Furthermore,chloroplast genes are inherited in a strictly maternal fashion in most angiosperm plant species,and this minimizes the possibility of out-crossing transgenes to related weeds or species.In addition,gene silencing,position effects and random integration have not been reported in chloroplast transformation.Although chloroplast transformation is very attractive,this technology is not as widely used as nuclear transformation.It has been mostly focused on 16 plants species,especially tobacco in which many proteins has been expressed including vaccines and antibodies.In this review we briefly summarize the rationales,methodologies,applications,bottlenecks and prospects of this promising genetic engineering technology for chloroplasts.
          2011,30(5):613-617, DOI: 1000-2421(2011)05-0613-05
          [Abstract] (1123) [HTML] (0) [PDF 914.54 K] (2951)
          Abstract:
          Pot experiment was conducted to study the effects of spraying different micronutrients and amino acids into the surface of leaves on yield and quality of Chinese cabbage (Brassica rapa L.).The results showed that methionine,zinc,molybdenum,boron and glycine could increase yield of Chinese cabbage.The treatments of spraying methionine,zinc and molybdenum increased yield of Chinese cabbage significantly.All treatments could reduce the nitrate content of Chinese cabbage with the highest decrease of 35.0% compared with the control.Molybdenum,boron,zinc and methionine might reduce nitrate content of Chinese cabbage significantly.Experiment also indicated that glycine,proline and selenium could both increase the contents of vitamin C,soluble sugar and soluble protein of Chinese cabbage.Therefore,spraying micronutrient or amino acids into the surface of leaves is a good application for increasing yield,reducing nitrate content and improving quality of Chinese cabbage.

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