Abstract:In order to explore the application of fertilizer and pesticide reduction,experiments with two factors and three levels were conducted to compare the effects of different fertilizer and pesticide reduction combinations on the incidence of main diseases and pests and yield in rice. The results showed that the reduction of fertilizer tended to reduce the incidence of disease and insects,whereas the reduction of pesticides had a tendency to increase the incidence of disease and insects. The incidence of rice sheath blight,fourth generation rice planthopper,and rice leaf borer was significantly affected by the reduction of fertilizer. By contrast,the incidence of rice sheath blight,third-and fourth-generation rice planthopper,and rice leaf borer was significantly affected by the reduction of pesticide. However,both reduction of fertilizer and pesticide had no significant effect on the incidence of rice blast,rice false smut,and rice borer. The reduction of fertilizer with approximately 30% significantly affected rice yield,leading to the harvest yield reduction of 10.29%. Compared with the control treatment,the reduction of fertilizer with less than 20% increased the harvest yield of green additive alternative treatment and biological pesticide alternative treatment 0.38% and 2.49%,respectively. It is indicated that biological pesticide and green additive alternative treatment can be used as technical measures for reducing the number of chemical pesticides.

Abstract:The Lipaphis erysimi (Kaltenbach) is one of the agricultural insects endangering cruciferous vegetables,and it has a rapid propagation speed and is distributed all over the world. Telomerase reverse transcriptase (TERT) is a catalytic subunit of telomerase,which not only can induce telomerase activity to affect cell aging and apoptosis,but also has other biological functions besides telomerase dependent. In order to clarify the mechanism of the telomerase reverse transcriptase (TERT) in insect growth and development,the TERT in L. erysimi (Kaltenbach) was cloned and its spatial and temporal expression was analyzed. According to the local transcriptome library,the related sequences of TERT gene of L. erysimi were screened,and the CDs sequences of TERT gene were cloned by gene amplification. The full-length sequence of the CDS region of the gene is 2 658 bp,which can encode 885 amino acid residues. Its secondary structure contains 41 alpha-helixes and 60 coiled coils. After uploading it to the NCBI,it was found that the gene has the highest homology with Diuraphis noxia,and has low homology with other species. The relative expression of TERT in different ages and tissues of L. erysimi was analyzed by real-time PCR. The results showed that the relative expression of TERT gene in the adult stage of L. erysimi was the highest,and there were significant differences with each age. The expression level of 1st instar nymph was significantly lower than that of adults,but significantly higher than that of 2nd,3rd and 4th instar nymphs. The expression level of 4th instar nymph was the lowest,but there was no significant difference with that of 2nd and 3rd instar nymphs. Subsequently,the 4th instar nymphs,which is basically mature and has the lowest expression level of TERT gene,was selected for dissection. We were able to simultaneously detect the expression of TERT gene in the head,chest and abdomen of 4th instar nymphs with the highest expression in the abdomen. These results suggest that the TERT gene plays an important role in the growth and development of L. erysimi,and the region with low similarity can be selected as the target region for gene interference or silence so as to control the major harm caused by L. erysimi in agriculture.

Abstract:The pathogenic fungi causing kiwifruit soft rots were isolated and identified by examining the morphological and microscopic characteristics,combined with the results of pathogenicity testing and rDNA-ITS (internal transcribed spacer) sequencing.The contril effect of carvacrol on kiwifruits soft rot was studied.The main pathogens causing soft rot of kiwifruit after harvest are Botryosphaeria dothidea and Phomopsis sp.,followed by Botrytis cinerea,Fusarium proliferatum and Alternaria sp.. Carvacrol had significant antifungal activity against the eight soft rot pathogens,especially for B.dothidea,with half effective concentration (EC50) of 8.87 μg/L.Simultaneously,carvacrol effectively reduced the incidence of kiwifruit soft rot in a simulated sales environment.The incidence of treatment group was only 50.17% of the control fruit when placed for 8 days,and it had no significant effect on the quality of kiwi fruit (P>0.05).Therefore,carvacrol has potential application value in controlling soft rot of kiwifruit after harvest.

Abstract:Using 49 filamentous fungi with whole genome sequence published as the research objects,OrthoVenn2 homologous gene cluster alignment,BLASTp comparison,keyword search and SMART were used to analyze the homologous gene and conservative domain of regulators of G-protein signaling (RGS). The results showed that there were 229 RGS in the 49 fungi,the number of RGS in each fungus ranged from 3 to 9,and the number of RGS of the necrotrophs and hemibiotrophs fungi was higher than that of the biotrophs fungi. According to the conserve domains,the RGS proteins could be divided into six types,including DEP-RGS,RGS-TM,PXA-RGS-PX,RGS,RGS-PAS-PAC,and TM-RGS,of which RGS with two special conserved domains,RGS-PAS-PAC and TM-RGS,were mainly concentrated in the hemibiotrophs and necrotrophs fungi. Further genetic analysis showed that RGS proteins with the same conserved domain were closely related. The above results indicated that there was a certain correlation between the parasitism and the quantity and species of RGS protein in plant pathogenic filamentous fungi.

Abstract:Xanthomonas campestris belong to Gram-negative bacteria,which mainly damage cruciferous vegetables and economic forests including walnuts and mangosteens,causing great economic losses to agricultural and forestry crops and seriously harming the healthy development of the agricultural and forestry industry. Secreted proteins play an important role in the pathogenic process of plant pathogenic fungi,bacteria,and oomycetes. There is no reports on the physicochemical properties and characteristics of secretary proteins of Xanthomonas. This study uses the secretary protein sequences of X. campestris B100, X. campestris pv. campestris str.8004,and X. campestris CN14 from the published genome-wide sequence as the basic data,and uses Protscale,SMART,TargetP 2.0 Server,and other bioinformatics software to analyze the physicochemical properties,conserved domains,and transit peptides of the secretary proteins above-mentioned. The results showed that there was no obvious rule between the theoretical isoelectric point of secretary proteins and the length of amino acids in X. campestris. An average 44.73% of the protein is unstable protein. An average of 83.21% of the protein has a total average hydrophilicity of less than 0,which is a hydrophilic protein. The number of proteins with obvious conserved domains in each secretary protein of Xanthomonas is 12 on average. All secretary proteins have signal peptides. The distribution of transit peptide prediction possibilities is relatively even.

Abstract:Twenty-two fungi with whole genome sequence published and the antiSMASH database were used to classify and annotate the gene clusters of synthesizing secondary metabolites of plant pathogenic fungi with different nutritional types in order to clarify the role of secondary metabolites of plant pathogenic fungi with different nutritional types in infecting plants and the differences in gene clusters. The results showed that the type and number of gene clusters of synthesizing secondary metabolites of hemi-biotrophs and necrotrophs fungi were higher than that of biotrophs fungi. The results of further analyzing the gene clusters of synthesizing secondary metabolites of non-ribosomal peptide synthetase,polyketide synthase and terpene showed that the number of NRPS gene clusters,PKS gene clusters and terpene gene clusters in hemi-biotrophs and necrotrophs pathogenic fungi were higher than that in biotrophs pathogenic fungi as well. It will provide an important theoretical basis for further analyzing the function of the gene cluster of synthesizing secondary metabolites of different trophic types of fungi and identifying new drug targets. Analyzing the gene clusters of synthesizing secondary metabolites in fungi and clarifying the differences in gene clusters of synthesizing secondary metabolites of different nutrition types of fungi is conducive to the better development of medicaments for preventing and controlling novel action targets of plant diseases.

Abstract:The pepper root system and soil samples were collected from the pepper planting area in Qimaba Township,Lüchun 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 using SPSS software. The results showed that when the mycorrhizal infection rate was the highest(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 the 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 abundance and density of AMF spore,the higher the mycorrhiza infection rate,the lower the incidence of pepper phytophthora root rot and the smaller the disease index. It can be seen that the existence of AMF in pepper root soil can enhance the disease resistance of pepper and reduce the occurrence of diseases.

Abstract:Puffer fish has a long history of food culture in China. Its taste is extremely delicious. It is rich in protein,amino acid and unsaturated fatty acid,but low fat content. Therefore,it can be used as a good dietary source for people. Earlier,puffer fish was forbidden to be sold and eaten for its highly toxic tetrodotoxin. As the breeding,tetrodotoxin controlling,and detoxification technologies developing,the domestic and internal market for puffer fish is gradually opening. Therefore,the economic value of puffer fish is gradually improving. We summarized the nutritional value of puffer fish,reviewed the research progress on puffer fish’s flavor,toxin,storage and processing. Meanwhile,we put forward the future research direction and developing trend of puffer fish,to provide a scientific reference for the development and utilization of puffer fish and its industry development in China.

Abstract:In recent years,people prefer convenient and healthy food,the consumption of precooked meat products has increased significantly. Deep-frying is a popular and fast method for reheating food. However,frying would result in some food hazard factors and high oil uptake. It was reported that air frying could give food lower oil content,and the quality similar to frying. However,the effect of air frying on food quality was different from frying for the different heat transfer media. It is necessary to optimize the air frying condition. The aim was to investigate the optimum condition of air frying for the fish paste/pork composite gel with fried flavor. The products were prepared from whole fish paste and pork by air frying. The gel properties were evaluated in terms of textural properties,water holding capacity and moisture content. The sensory quality and chroma were also measured. The results showed that the air-fried samples had the golden color and flavor and taste of fried food. In addition,air frying decreased the moisture content,and increased the water holding capacity. In contrast,air frying at low temperature (60~130℃) hardly influenced the quality of fish paste/pork composite gels,while air frying at high temperature (160~200℃) significantly improved the sensory score and breaking force. When air-frying time was more than 6 min,both springiness and cohesiveness of air-fried gels were obviously higher than unfried samples. The hardness and chewiness of samples increased followed by a decrease with extension of air frying,indicating that long-time frying had a negative influence on the textural properties. In conclusion,air frying at 200℃ for 6 min was the optimum condition for fish paste/pork composite gels with fried flavor.

Abstract:In order to solve the problem of excessive water consumption in the surimi rinsing process,and to study the effect of ozone rinsing on the quality of surimi,silver carp surimi was prepared by traditional rinsing,one ozone rinsing,and mixed rinsing with tap water and ozone water. The effects of three modes of ozone water rinsing on the strength,color and bad smell of surimi gel were compared. The results showed that the carbonyl content increased with increasing ozone concentration,and carbonyl content in surimi rinsed with one ozone water was higher than surimi with the other rinsing modes. For the samples with one ozone rinsing,the proteins were oxidated to a higher extent,and formed more aggregates,resulting in a poor gel performance. Mixed rinsing could reduce fat oxidation,reduce the oxidation degree of surimi protein by ozone,and improve the whiteness and gel strength of surimi gel. In addition,mixed rinsing with an ozone concentration of 8 mg/L could effectively improve the quality of surimi. At the same time,the water consumption was reduced by 1/3,achieving the purpose of water-saving rinsing.

Abstract:Taking Nemipterus virgatus surimi as the research object,the effect of transglutaminase on the 3D printing characteristics of Nemipterus virgatus surimi was studied from three aspects:apparent viscosity and rheological properties (difficulty or ease of conveying),printing effect (appearance,molding performance),and the properties of surimi product. As the transglutaminase addition increased,the gel strength,elasticity,and water holding capacity of Nemipterus virgatus surimi gel increased firstly and then decreased. When the transglutaminase addition was 0.2%,they reached the highest value,which were increased by 70.88%,25.01%,and 9.72% compared with the control group,respectively. The relative content of immobilized water in the surimi reached the maximum when the transglutaminase was added at 0.2%,and the T23 peak ratio was 0.97. The apparent viscosity,yield stress,consistency and rheological properties of Nemipterus virgatus surimi gradually increased with increasing transglutaminase addition,while the fluidity decreased. The apparent viscosity reached the maximum at 0.4% transglutaminase,and loss modulus and loss tangent at 0.2% transglutaminase. The surface of the sample with 0.2% transglutaminase was relatively integral and matched the set model,and the continuity and adhesion between the surimi threads were relatively high. In summary,addition of 0.2% transglutaminase was the best for printing the Nemipterus virgatus surimi gel product.

Abstract:With pork and whole fish paste as raw materials to make fish paste/pork composite gel,steam,microwave,frying and air frying were used for reheating. The effect of reheating methods on the sensory qualities,gel properties and fat contents of fish paste/pork composite gel was investigated. The aim was to explore a healthy reheating method for fish paste/pork composite gel with fried flavor. Compared with the control sample,all of the four reheating methods improved the breaking force,deformation and water holding capacity of the fish paste/pork composite gel,and reduced the water content. Among these,air frying had the best improving effect on the deformation and water holding capacity. Frying and air frying obviously reduced the L* value,increased the a* and b* values of the gel. The product after air frying owned a bright golden yellow color,similar to the product after frying. The flavor of the air fried sample was the closest to that of the fried sample. In addition,the oil content of the air fried sample was about 50% of the fried sample. In summary,the fish paste/pork composite gel with low fat content can be produced by air frying and reheating. Air frying was the optimal reheating methods for producing fish paste/pork composite gel with fried flavor.

Abstract:The addition of fish minced meat and bone powder to flavour sauce by certain processing could not only improve the nutritional value of flavour sauce,but also provide a reference for the development of new type of flavour sauce and the comprehensive utilization of by-products of aquatic product processing.Moreover,it could give a new idea for the healthy development of fishery industry.The Millard reaction solution and fish bone powder were prepared from processing by-product of Ictalurus Punctaus (the fish bone with meat),and added to the soybean sauce to develop the flavour sauce with high calcium content.The formulation of high calcium flavour sauce was optimized through single factor and orthogonal experiments using sensory score as index.The results showed that the order of influencing the high calcium flavour sauce was the addition amount of soybean sauce＞sugar＞vegetable oilMaillard reaction solution.The optimized formulation was 30.4 g/100 g of soybean paste,4.8 g/100 g of sugar,16.8 g/100 g of vegetable oil,6.8 g/100 g of Maillard reaction solution.The high calcium flavour sauce made according to the formula was sweet in flavor and excellent in overall quality.The calcium content of flavour sauce was 353 mg/100 g after addition of fish bone powder,which met the claim of high-calcium food.

Abstract:An electric self-propelled double-track transporter without a wire rope was designed to solve the safety problems caused by messy rope and rope squeezing when the wire rope traction double-track transporter is operating on a curved and undulating track.The transporter is powered by Santuo GW114165 motor using two 12-LPA-24 lead-acid batteries as energy source,and adopts rear drive transmission mode of one-active and multi-slave.The safety and stability of the transporter was verified through tests of current test,level ground energy consumption and skid.The three-factor three-level orthogonal test method was combined to study the effects of materials of driving wheel,track slope and loading quality on the speed of transportation.The results showed that the rear drive transmission mode of one-active and multi-slave has good performance of climbing and relatively stable operation under the test conditions.Stopping at a steep slope under a full-load climbing state should be avoided as possible.If it needs to stop,it can be started manually.The running speed of the transporter is 0.241-0.700 m/s,and the range on flat ground is 3 560-6 489.1 m.The effects of material of driving wheel,track slope and loading quality on the speed of transportation is in the decreasing order of track slope,material of driving wheel and loading quality.The track slope has the most significant impact on the running speed with a Sig value of 0.049,which is less than 0.05.

Abstract:In order to solve the severe vibration problem of hilly orchard transporter in practice, a semi-active suspension system using CDC dampers was designed and the loading tests were carries out. An orchard road input model was first established as well. When using the road input model established to select a simulated road, the α is 0.9, the coefficient of corresponding road roughness is 4 096×10-6 m3, and the vehicle speed is 10 m/s. A road input model was created in MATLAB/Simulink, then the semi-active suspension and passive suspension models were established, and MATLAB was used to establish the Simulink model of the fuzzy PID controller based on the suspension system dynamics model. The parameters of the semi-active suspension were analyzed and adjusted to obtain the ideal simulation response results. The results showed that the performance of the semi-active suspension system is 10%-20% higher than that of the passive suspension system. Finally, the mechanical structure of the semi-active suspension system was designed and the loading test of the system was carried out. The mechanical structure of the semi-active suspension system is made up of elastic elements, shock absorber reformation, guiding mechanism and various parts connecting parts, and semi-active suspension. The system is arranged according to the layout space of the front axle. The shock absorbers are arranged in an oblique arrangement with a horizontal angle of 30°. The elastic elements are arranged vertically. The guide mechanism is installed in the middle of the front axle to limit the front and rear of the front axle and constrain the vertical movement trajectory. According to the fuzzy PID controller designed, the control circuit system is designed and the semi-active suspension is tested. The vibration test system is built using the vibration instrument and the vibration sensor and the vibration signal of the Z axis of the seat position of the vehicle is tested during driving. Under certain conditions of speed and load, the test results of the semi-active suspension before and after loading showed that the vibration reduction of the transporter equipped with the semi-active suspension reached 50%, meeting the design requirements of the semi-active suspension system. The vibration frequency range of the vehicle body equipped with a semi-active suspension system is greater than 8 Hz, indicating that the vehicle has good driving comfort. Although this paper has done a certain theoretical analysis on designing the semi-active suspension system of the wheeled transporter for hilly orchard, there are still many things that can be further studied and expanded. For example, neural network or genetic algorithm can be used to optimize the fuzzy PID controller so that it can respond better to road excitation. When the system is in motion simulation, Adams can be used to perform kinematics simulation analysis, analyze the mechanical performance of the system in motion, and optimize its design.

Abstract:In order to realize the rapid transportation of the pot seedlings of fruit trees in the nursery fields,a self-propelled electric double-track transporter for the nursery fields was developed. According to the application environment of the transporter,the quality of pot seeding of fruit trees and other requirements,the main technical parameters including the the loading capacity,operating speed,remote control distance,and motor battery was proposed. According to the requirements of technical parameters. The overall structure of the transporter was determined and the key components such as vibration damping,leveling and limit mechanism were designed. Among them,the overall structure of the transporter was mainly composed of a cargo trolley and a traction head used for traction of the cargo trolley,and which had the functions of obstacle avoidance,remote control and automatic walking. This transporter chooses a customized lithium iron phosphate battery as its power supply. The battery dimensions were 440,235,and 230 mm in length,width and height respectively. The voltage was 24 V,the battery mass was 22.4 kg,and the battery capacity was 220 A·h. The driving mode of the transporter was a four-wheel drive direct-drive traction head to pull the cargo trolley to slide on the track through the traction component. The circuit based on PLC control was designed,which includes wiring module,insurance module,travel switch circuit module,motor controller module,remote control module,indicator light module,obstacle avoidance module and encoder control. The vibration damping and leveling mechanism of the transporter was fixed between the support leg and the bracket. Each leveling mechanism was composed of 4 springs,a perforated splint fixed on the frame,4 sleeve shafts,4 positioning and 4 screw nuts. The limit mechanism of the transporter includes a universal bearing to prevent rail collision,an anti-rollover wheel to prevent rollover,a load-bearing pulley or a driving friction wheel,and its function was to limit the transporter to travel along the track. After the design was completed,tests in both lab and nursery fields were carried out. The results of test showed that the transporter can adapt to the muddy working environment of the nursery fields,with a load capacity of 750 kg. According to the outdoor test,every 100 m of the transporter forward,the energy consumption of no-load was 9.16 W·h,while the full-load was 27.6 W·h,and the running speed of the transporter was 0.564-0.718 m/s. It took less than 2.5 s for the transporter from starting to a uniform speed,less than 2.2 m for the brake glide distance of the transporter and less than 0.05 m for the emergency brake distance. Additionally,the vibration acceleration amplitude of the transporter was less than 0.4 g in general. In conclusion,the transporter was designed and manufactured,which can improve the efficiency of transportation,reduce labor intensity,and ensure safety during transportation.

Abstract:In order to further improve the flexibility of mountain orchard transport,this paper proposes a cable-towed trackless transporter for hilly orchard.The low-altitude transportation in orchard is realized by setting up the pile point on the hilly orchard,controlling the movement of paralleled steel cable.According to the actual terrain situation in Ganzhou,the actual standard used by the system model is that the horizontal distance between two piles located at the top of two mountains is set at 3 200 m,the mountain height is set at 240 m,and the height difference between adjacent mountains is set within 10-50 m.According to the actual situation of the slope angle,the inclination angle of the transportation route down the mountain was set as 36.87° The total weight of the fruit basket filled with fruit picked was set at 100 kg.The main transportation process of the transporter is as follows:the fruit basket filled with fruit picked is placed on the pile platform at the top of the hill and suspended on the hook at the end of the cable.Each hook is connected to 2-3 cables,and the other end of each cable is connected to a drum connected to the motor and the reducer.Each cable is controlled by a separate motor,and the speed of the cable is controlled by motor speed control,so that the fruit basket can be transported downhill in different paths and speeds.In order to reduce the swing deviation caused by the own mass and motion of cable and eliminate the response hysteresis and critical jitter of system,an independent lifting control device is set up for the fruit basket.The only control is realized by installing the button at the end of the sling to ensure the temporary lifting of the fruit basket not be affected by the movement of cable.Based on three-dimensional route model,the parallel mechanism consists of three piles,and the working scope of the equipment is the triangular area enclosed by the piles.For the convenience of analysis and calculation,the transportation routes of all fruit baskets in the model are approximated as straight lines.By analyzing the motion model of the device,the relation of the motion speed between the three cables is obtained to provide a theoretical basis for regulating motor speed.By a transport mechanics model the traction on the cable is about time with the dual function of the angle.The horizontal distance is flexible to set parameters,the angle and subject to change with the change of the three-dimensional length,velocity can be obtained to adjust the parameters according to the practical application of control motor.The results of simulating the model with Matlab software showed that the initial speeds of cable b and c changed within 1-2 m/s and gradually decreased with the increase of time when cable a kept moving at 2.5 m/s for the three-pile parallel mechanism of transportation.The initial velocity of the cable decreased as the deflection angle increased.In the process of transportation with a uniform drop of the fruit basket,the traction force on cable a,b and c gradually increased with the increase of time.The increase rate of cable a is the largest,while the increase rates of cable b and c are the same basically but less than that of cable a.Within the scope of the changing the angle α,when the angle is the median cable on a traction,the limit value is the biggest when the cable on both sides of a traction is the smallest.The cable force on b decreases gradually with the increase of angle,and is negatively correlated with the angle.The cable force on the c increases with the increase of angle.The simulation data obtained by modeling fits with the mathematical model,indicating that the model is correct and reliable.The independent lifting sling system controlling the rise and fall of fruit basket make the whole transport process streamlined.Orchard topographic simulation is based on establishing a transporter mechanics model and numerical simulation analysis.The results of simulation showed that the speed and traction on the cable changed slowly and evenly during transportation under the different transportation path angle.The method of analyzing the parallel mechanism with three-dimensional route model can be used to simulate the transportation between two and several hilly orchard.The parallel mechanism guarantees the stability of the system during operation and its flexibility will expand the scope of applying the transporter further.

Abstract:Aiming at the problems of high labor intensity and low work efficiency in digging holes in mountain forests and fruit tea gardens,this research designed an electric self-propelled hole digging machine with driving power in mountain forests and fruit tea gardens. The machine has the characteristics of driving power,automatic completion of the feed stroke and reset stroke of the drill bit,simple and compact overall structure,and the ability to stably carry out digging operations on a 15° slope. In terms of overall structure,the digging machine is composed of a digging mechanism,an automatic lifting mechanism,a walking mechanism,a supporting mechanism,a control system and a frame. Among them,the digging mechanism is composed of a 48 V DC motor,a conversion head and a drill bit; the automatic lifting mechanism is composed of a power transmission system,a guide mechanism and a stroke limiting device; the walking mechanism is composed of a 24 V hub motor and a universal wheel; the supporting mechanism is composed of movable The supporting frame,connecting rod and adjusting device are composed; the frame is formed by welding 30 mm×30 mm square steel. In terms of digging performance test,the 5-point sampling method was used to select 5 test points in 2 citrus orchard test sites and 1 tea plantation test site for testing. Among them,the depth of the citrus test ground was 20 cm,and the average soil moisture content was measured. They are 24.30% and 18.49%. The average soil compactness is 437 and 837 kPa,respectively; the soil depth of the tea garden test site is 20 cm,the average soil moisture content is 22.01%,and the average soil compaction is 372 kPa. In terms of climbing performance test,the slopes with gradients of 5.4°,8.4° and 15.2° were selected for the climbing test,starting from the junction of the straight road and the slope,measuring the slope of 9 m with a tape measure,and selecting the next 5 m as the test road section. Stop the digging machine on a straight road close to the ramp. After the walking motor starts to rotate,open the switch to climb the slope. Use a stopwatch to measure the time the digging machine passes the test section. In terms of the maximum walking speed test,the wheels reached a stable maximum speed when walking about 6 m on the orchard road through the preliminary test. In order to reduce the road slope error,the test is carried out by taking the average value of the round-trip measurement. The first 10 m and the last 10 m are the acceleration section or the deceleration section,and the 10-30 m is the test section. Taking into account the effect of accidental errors,6 repeated tests were performed,and the time to pass the test section was measured with a stopwatch. The test results show that the average digging time for a single operation of the digging machine is 50.7 s,which is 1.77 times faster than the manual hoe digging; the energy consumption of a single effective digging operation is 6.38 W·h,the average fertilization depth is 392.5 mm,and the average fertilization is The hole diameter is 303 mm,which meets the agronomic requirements for fertilization; the walking speed is 1.237 m/s,and it can smoothly pass a 15° slope,which meets the actual operation requirements of hole digging in mountain fruit tea gardens. The innovation of this research lies in that the feed and return movement of the drill bit during the digging operation does not require manual operation,which can improve work efficiency,reduce labor intensity,and ensure the safety of the digging operation.

Abstract:Fruit output of China ranks first in the world.The fruit industry,as a labor-intensive industry,has a great demand for labor force.However,the shortage of labor force,high intensity of manual labor and low efficiency in the current market have become one of the important problems hindering the industrialization development of orchards.Therefore,realizing the mechanization of orchard production is a necessary means to liberate labor force and improve production efficiency.At the same time,due to the vigorous implementation of raw grass mowing technology in orchard soil management in China,orchard raw grass can regulate the moisture content in the soil,and weeds covered on the soil surface after mowing can be used as fertilizer for fruit tree.However,irregular mowing will have a lot of adverse effects on fruit trees and affect normal orchard management.Cutting weeds in orchard is an important task of orchard management.The level of agricultural mechanization in underdeveloped hilly areas has caused a lot of labor consumption on orchard management.At the same time,traditional chemical weeding greatly polluted orchard.Therefore,the mechanical stubble weeding in orchard plays an important role in protecting orchard soil.The realization of efficient mechanical weeding has become an urgent goal to be achieved in the process of orchard mechanization.Most orchards in China are located in hilly and mountainous areas with complex planting terrain conditions and imperfect road planning.Currently,weeding machines used in hilly orchards are generally flat orchards and field weeding machines.The artificial knap-type and hand-pushed weeding machines of flat orchards are time-consuming and laborious.Field weeding machines are driven by tractors,with high cost and large overall size,which are difficult to meet the requirements of mechanization of hilly orchards.Therefore,it is of great practical significance to study the mowing machine in hilly orchards to promote the development of fruit industry.Raw grass mowing is a modern orchard management mode widely promoted at home and abroad in recent years.The weeding performance of orchard mowing robot is closely related to the physical properties of weeds and design parameters of swinging blade.A mowing robot for hilly citrus orchards was designed based on a Y-type flapping blade mowing mechanism to solve the complex terrain conditions of citrus orchards in hilly areas and the difficulty of applying the existing weeding machinery.The kinematics model of single stalk cut by flapping knife was established with D-H method.The parameters of swinging blade designed were explored through single factor experiment of recutting rate.Results showed that the impact force of single weed stem was 74.25 N under the condition of no grass entanglement.The cutting path of blade was deduced.The recutting rate decreased with the increase of blade spacing,cutter shaft speed and forward speed of robot.

Abstract:Vertical farms are one of the latest research directions in the interdisciplinary field of agriculture and the building environment. This article uses CNKI,Scopus and Web of Science (WoS) as databases,and selects 184 domestic and foreign related literatures by searching keyword. The bibliometrics methods are used to quantitatively analyze them,and summarize the current status and development trend of vertical farm research and the challenges. The results showed that the development of the first 10 years was relatively slow,and there were few related literatures published after the concept of vertical farms was proposed in 1999. After 2010,the development has accelerated,and the number of literatures has shown an overall upward trend. But regardless of the overall number or the inclusion of the core database,related research is still very insufficient. An analysis of 21 documents in the WoS core collection database found that the latest research focus is not only in the direction of agricultural science and technology,but also in the direction of environmental science,especially in the direction of the building environment. Based on comparatively analyzing the research content of various literatures,the research hotspots of vertical farms are further refined and summarized,and research methods are sorted out. At the same time,the technical,economic and feasibility of vertical farms are analyzed,and the direction of future technology development is elaborated.

Abstract:In order to further analyze the functions of BXL family genes in the development of stem,16 genes encoding putative BXL proteins were identified in the whole genome of Brassica juncea var. tumida with bioinformatics methods. The gene structure and conserved motifs,chromosomal distribution and gene expression during the swelling of stem of BjuBXL family genes and the physicochemical properties of BjuBXL family protein were systematically analyzed. The results showed that 16 BjuBXL genes were classified into 7 categories and 2 sub-families according to the phylogenetic tree analysis,among which BjuBXL1-1，BjuBXL1-2，BjuBXL1-3 and BjuBXL1-4 are closely related to AtBXL1,which is involved in cell wall metabolism and plant development in Arabidopsis. 7 BjuBXL genes were located in 5 chromosomes of A subgenomes and 8 BjuBXL genes are located in 4 chromosomes of B subgenomes. The results of fluorescence quantitative PCR analyses showed that the transcriptional levels of BjuBXL1-1and BjuBXL1-2 were up-regulated obviously during the swelling of stem. The expression in the inner pith (P2-P4) were significantly higher than that in regions of the outer pith of swollen stem (P1),indicating that BjuBXL1-1 and BjuBXL1-2 may play an essential role in the cell wall metabolism of inner pith during the swelling of stem.

Abstract:In order to investigate the relationship between estrogen receptor (ER) genes and growth of different sexes and ploidy in fish,loach（Misgurnus anguillicaudatus）whose female growth is faster than that of male and whose tetraploid growth is faster than diploid were selected as the research object in this study.We firstly cloned the cDNA sequences of three ER genes of loach,including ERα (1 821 bp),ERβ1 (1 008 bp) and ERβ2 (1 197 bp).Amino acid sequence alignment revealed that the loach ER genes shared higher similarity with corresponding subtypes of carps.Quantitative RT-PCR was used to detect the expression of ER genes at five growth stages of diploid loach,as well as in different tissues in diploid and tetraploid adults.The results showed that the three ER genes were differentially expressed in the brain,muscle,liver,and gonadal tissues of the male and female individuals before and after sexual maturity.Among them,the expression of ERα in the brain,muscle and gonad tissues of males was significantly higher than that of females (P<0.05),and expression in the female liver was generally higher than that in males (P<0.05).The expression levels of ERβ1 and ERβ2 in the testis were always high.Comparison results between different ploidy showed that expression of the three ER genes in the diploid brain were significantly higher than that of the tetraploids,and the expression levels of males were higher than that of females,with the expression of ERα being the most significant.The results of this study indicated that regardless of the difference between ploidy and sex growth, ERα appears to have relatively high expression in the brain of slow-growing (diploid,male) individuals.Therefore,we speculate that the ERα gene in the brain might have a certain inhibitory effect on the growth rate of fish.

Abstract:To study the structural characteristics of Langerhans cells (LCs) and the effect of bacterial infection on the expression of functional genes of LCs in yellow catfish,the LCs in immune tissues of yellow catfish were identified by immunohistochemical (IHC) technique,the ultrastructure of LCs was further observed by transmission electron microscope (TEM) technique,and the expression levels of IL-1β,TNF-α,IL-10 and TLR-4 genes related to the function of LCs in the immunity related tissues of yellow catfish were detected by real-time quantitative PCR in this study. The results showed that the CD207 protein,a specific molecular marker for LCs,were detected in the head kidney and spleen,and the structure of the yellow catfish LCs was similar to that of other vertebrates,with granules arranged radially around the centriole in cytoplasm. The expression levels of the IL-1β,TNF-α,IL-10 and TLR-4 genes in the immunity related tissues of yellow catfish were significantly up-regulated after Edwardsiella ictaluri infection. The above results indicated that the LCs were distributed in yellow catfish,and they may participate in the body′s immune response against E. ictaluri infection.

Abstract:In the present study,the effects of histidine and histamine on food intake were evaluated through intraventricular (ICV) administration in Chinese perch (Siniperca chuatsi),and the primary cells of Chinese perch were stimulated with different concentrations of histidine and histamine. The food intake changes were examined within 24 h after ICV,and the changes of the appetite genes and amino acid sensing signaling pathways were detected. The results showed that histidine and histamine significantly decreased food intake at 12 h post-injection,compared with the control group. Meanwhile,the mRNA expression of npy,gcn2 and atf4 were significantly decreased (P<0.05),whereas the mRNA expression of agrp and mtor were not significantly changed (P>0.05). At the cellular level,compared with the control group,1.0,2.0 and 3.0 mmol/L of histidine obviously inhibited the expression of the npy mRNA (P<0.05),and this inhibitory effect increased with increasing concentration. At the same time,1.0 and 3.0 mmol/L of histidine also significantly inhibited the expression of the agrp mRNA (P<0.05). In addition,different concentrations of histamine did not cause changes the npy and agrp mRNA expression (P>0.05). Besides,2.0 mmol/L of histidine didn’t significantly change the phosphorylation level of protein S6,the downstream signaling of mTOR pathway. Our results suggest that histidine and histamine can inhibit the food intake of Chinese perch. Histidine suppresses food intake through its conversion into neuronal histamine,and the inhibitory effect of histidine and histamine on food intake might be mediated through down-regulating the expression of appetite-promoting genes.

Abstract:In order to explore the anti-inflammatory effect and its underlying mechanism of Senecio scandens,petroleum ether extract of S. scandens (PEESS) was used to treat the lipopolysaccharide (LPS)-induced RAW264.7 cell. The cell proliferation was detected by CCK-8,the secretion of NO was detected by Griess method,and the expression of inflammation-associated factors was detected by RT-PCR and Western blot. The results showed that PEESS at 0-80 μg/mL had no significant effect on the proliferation of RAW264.7. However,it significantly inhibited the secretion of NO in LPS induced RAW264.7 cells by a concentration-dependent manner. Besides,the expression of IL-1β and IL-6 was significantly inhibited by PEESS in LPS induced RAW264.7 cells. Meanwhile,PEESS also significantly reduced the expression of p-NF-κB p65 and p-p44/p22 MAPK proteins. In conclusion,the above results indicated that PEESS may participate in the process of anti-inflammatory response by inhibiting the expression of some pro-inflammatory mediators such as NO,IL-1β and IL-6,and the activation of the NF-κB and MAPK signaling pathways. This study lays a foundation for the application of S. scandens in cuing some inflammatory disease of animals.