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    2020,39(6):1-7                                                                                                                
    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.
    2020,39(6):8-14                                                                                                                
    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.
    2020,39(6):15-22                                                                                                                
    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.
    2020,39(6):23-29                                                                                                                
    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.
    2020,39(6):30-36                                                                                                                
    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.
    2020,39(6):37-43                                                                                                                
    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.
    2020,39(6):44-49                                                                                                                
    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.
    2020,39(6):50-58                                                                                                                
    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.
    2020,39(6):59-66                                                                                                                
    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.
    2020,39(6):67-73                                                                                                                
    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.
    2020,39(6):74-81                                                                                                                
    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.
    2020,39(6):82-87                                                                                                                
    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.
    2020,39(6):88-95                                                                                                                
    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.
    2020,39(6):96-104                                                                                                                
    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.
    2020,39(6):105-112                                                                                                                
    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.
    2020,39(6):113-120                                                                                                                
    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.
    2020,39(6):121-127                                                                                                                
    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.
    2020,39(6):128-135                                                                                                                
    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.
    2020,39(6):136-143                                                                                                                
    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.
    2020,39(6):144-154                                                                                                                
    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.
    2020,39(6):155-163                                                                                                                
    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.
    2020,39(6):164-172                                                                                                                
    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.
    2020,39(6):173-179                                                                                                                
    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.
    2020,39(6):180-186                                                                                                                
    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.
    2020,39(6):187-191                                                                                                                
    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.
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    Abstract:
    D101 resin was used to obtain polymethoxyflavones extracts from the Chenpi . High-speed countercurrent chromatography was used to obtain nobiletin and tangeretin. The purity was identified by high performance liquid chromatography. The structure was identified by mass spectrometry and 1H NMR. The mice model of acute lung injury was constructed by intranasal instillation of LPS in the exprienment.Continuous gastric gavage with 25, 50, 100mg/kg low , medium,high-nobiletin group and 250mg/kg PMFs group for 7d.The anti-oxidant and anti-inflammation of PMFs and NOB was evaluated by assessing pulmonary histopathological changes,lung injury score,the wet weight to dry weight ratio, MPOactivity, MDA content, GSH-PX activity,the cytokine content of lung tissue.The results showed that the PMFs group and middle-NOB group can significantly relieve lung tissue damage, reduced the wet/dry weight ratio, MPO activity, MDA content and pro-inflammatory cytokine content, increased GSH-PX activity.The anti-oxidation and anti-inflammatory effects of the middle-NOB group and the 10 mg/kg dexamethasone group on acute lung injury mice are similar. The above results indicated that PMFs extracts and NOB have anti-oxidant and anti-inflammatory effects, and have certain protective effects on acute lung injury.
                                                                                                                   
    Abstract:
    Abstract: 【Objective】By comparing and analyzing the 2 varieties winter wheat changes of stem morphological characteristics, basal node coarse cell wall composition and stem mechanical characteristics under different molybdenum-nitrogen ratio treatments, to explore the effect of molybdenum and nitrogen combined application on lodging resistance of winter wheat. 【Method】 By using 97003 and 97014 as materials, four nitrogen application levels (N 0 kg/hm2, N120 kg/hm2, N 210 kg/hm2, N 300 kg/hm2) and three Mo application levels ((NH4)2MoO4 0 kg/hm2, (NH4)2MoO4 0.75 kg/hm2 and (NH4)2MoO4 1.5 kg/hm2 were set up to compare the lodging rate of different, and the reasons of wheat lodging difference were analyzed from physiological, morphological and mechanical indexes. 【Result】 1) The distance from the break to the top and the bending moment of the wheat molybdenum low-efficiency cultivar 97014 at the same nitrogen and molybdenum levels were higher than those of the wheat molybdenum high-efficiency cultivar 97003; compared with no nitrogen application, the three levels of nitrogen application could increase both varieties of wheat the upper fresh weight and bending moment, the difference was more obvious when the nitrogen level was 210 kg N/hm2, nitrogen application had a significant effect on the section coefficient and bending stress. The nitrogen level was 0 kg N/hm2 and 210 kg N/hm2 , the bending moment would increase as the amount of molybdenum applied increases; 2) The basal node length of wheat variety 97003 was higher than that of wheat variety 97014 under all Mo and N fertilization levels, while the upper node length and ear length were lower than that of wheat variety 97014; the outer diameter of long axis and the inner diameter of long axis and ear length of wheat molybdenum efficient variety 97003 increased with the increase of nitrogen application level In addition, the outer diameter and inner diameter of long axis, basal stem length and ear length of wheat variety 97014 increased with the increase of nitrogen application level; 3) With the increase of nitrogen application rate, the non structural carbohydrate of wheat stem decreased significantly, and the application of (NH4)2MoO4 1.5 kg/hm2 efficient wheat variety 97003 was observed Ammonium Molybdate / hm2 can reduce the amount of non structural carbohydrate in wheat stem; 4) The cellulose and lignin content in the base of two wheat varieties were different. The cellulose and lignin contents of 97003 wheat variety with high molybdenum efficiency were basically unchanged under all treatment levels. The cellulose content of wheat variety 97003 with low molybdenum efficiency was increased by applying (NH4)2MoO4 1.5 kg/hm2 under four nitrogen levels. The lignin content of basal internode decreased when 0.75 kg/hm2 (NH4)2MoO4 was applied at 210 kg N/hm2 and 120 kg N/ hm2 . 【Conclusion】 The optimal combination of the main physical properties of the two winter wheat lines under different Mo and N application rates were different. The short and thick basal internode, large stem wall thickness, increased total amount of structural carbohydrates and good stalk plumpness were the direct reasons for the high bending resistance, small lodging index and enhanced lodging resistance of winter wheat.
                                                                                                                   
    Abstract:
    Food safety analysis and clinical diagnosis are closely related to people"s health. How to improve the ability of food safety analysis and clinical diagnosis have always been the focus of all over the world. As an efficient and convenient method, rapid detection has been considered as an important means to break through this problem. And magnetic relaxation switching (MRS) biosensor has become a new tool for rapid detection due to its excellent analytical performance and simple analysis process, which has been used in the field of public health. In order to improve the performance of the MRS biosensors, researchers have done a lot of works such as exploring effective signal conversion mechanism, constructing new nanometer magnetic probe, developing efficient signal amplification system and improving the stability of the sensor, which has greatly promoted the development of rapid detection. In this paper, different sensing mechanisms, recent research progress and applications of MRS biosensors are reviewed.
                                                                                                                   
    Abstract:
    Carotenoids and anthocyanins are antioxidant metabolites that are involved in photoprotection, and contribute to the color of leaves, flowers and fruits. Meanwhile, fruits are rich in carotenoids and anthocyanins metabolites, which is beneficial to human health. This review summarized the studies of the effects of light signaling on carotenoid and anthocyanin accumulation and its biosynthetic genes, the major transcription factors and complexes that participate in these pathway. Besides, understanding the crucial role of the transcriptional regulation of carotenoid and anthocyanin by the light may help us to explore effective pathways and targets for fruit quality improvement, and promote carotenoid and anthocyanin accumulation via genetic engineering and environmental treatment.
                                                                                                                   
    Abstract:
    To investigate the effects of phosphate fertilizer reduction and zinc fertilizer application on the yield and quality of Guanxi pomelo in Pinghe County, the white flesh Guanxi pomelo in Pinghe area was used as the test material, and six treatments were set up including: 70% reduction in phosphorus combined without zinc fertilizer, 70% reduction in phosphorus combined with zinc fertilizer, 35% reduction in phosphorus combined without zinc fertilizer, 35% reduction in phosphorus combined with zinc fertilizer, the habitual amount of phosphorus combined without zinc fertilizer, the habitual amount of phosphorus combined with zinc fertilizer. Results showed that reducing the amount of phosphate fertilizer can increase fruit yield and improve fruit quality. When phosphate fertilizer is reduced by 35%, the fruit yield will increase significantly, and it can significantly reduce the weight of single fruit and thick skin, increase vitamin C, solid-acid ratio and other indicators; 35% reduction in phosphorus combined with zinc fertilizer can significantly increase fruit yield, comprehensive quality score, fruit juice rate, water content and vitamin C content. Field test results showed that Phosphate fertilizer can be reduced by 35% in Pinghe Guanxi pomelo orchard., Phosphate fertilizer reduction by 35% combined with zinc fertilizer can significantly increase yield and improve fruit quality, it was phosphate fertilizer (P2O5) 0.85 kg/(plant·a), two sprays of 0.2% zinc fertilizer (ZnSO4·7H2O) 40 g/( plant·a).
                                                                                                                   
    Abstract:
    Orange slices are prone to browning in the drying process. In order to better maintain the color of orange slices during processing, the effects of five different color fixatives (ascorbic acid, citric acid, L-cysteine, sodium sulfite and β-cyclodextrin) on browning of orange juice and orange pomace were studied. And different ultrasonic power intensity (30%, 40%, 50%) was used to pretreat and then treated with color fixatives. The product was baked at 70 ℃ for 8 h, and its color was determined every 1 h to explore the best anti-browning treatment conditions. The results showed that 0.20% sodium sulfite treatment had the best anti-browning effect when the color fixatives was treated alone; combined with ultrasonic pretreatment, the best anti-browning effect in orange juice and pomace was 40% ultrasonic power intensity combined with 0.20% sodium sulfite, which was verified on orange segments to have the most obvious anti-browning in this condition.
                                                                                                                   
    Abstract:
    in order to explore the anti-inflammatory effect and underlying mechanism of Senecio scandens, Petroleum ether extract of Senecio scandens(PEESS)was used to treat the lipopolysaccharide(LPS)-induced inflammation response in mouse mononuclear macrophages RAW264.7. The cell proliferation were detected by CCK-8, and the secretion of NO were detected by Griess method, and the expression of inflammation-associated factors were 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 can significantly inhibit the secretion of NO in LPS induced RAW264.7 cells by a concentration-dependent manner. And the expression of IL-1β and IL-6 were significantly inhibited by PEESS in LPS induced RAW264.7 cells. Meanwhile, PEESS also significantly reduced the level of p-NF-κB p65 and p-p44/p22 MAPK proteins. In conclusion, 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 Senecio scandens in cuing some inflammatory disease of animals.
                                                                                                                   
    Abstract:
    In order to investigate the relationship between estrogen receptor genes and growth differences in sexes and ploidy of fish, loach(Misgurnus anguillicaudatus)with females growing faster than males and tetraploids growing faster than diploids were selected as the research object in this study. We firstly cloned the cDNA sequences of three estrogen receptor genes of loach, including ER (1821 bp), ERβ1 (1008 bp) and ERβ2 (1197 bp). Amino acid sequence alignment revealed that loach ER genes have higher homology with corresponding subtypes of carps. Quantitative RT-PCR was used to detect the expression of ER genes in five growth stages of diploid loach as well as diploid and tetraploid adults. The results showed that three genes were differentially expressed in brain, muscle, liver, and gonadal tissues of male and female individuals before and after sexual maturity. Among them, the expression of ERα in brain, muscle and gonad tissues of male individuals was significantly higher than that of females (P<0.05), and the expression in female liver tissues was generally higher than that in males (P<0.05). The expression levels of ERβ1 and ERβ2 in testis tissue were always in high level. Comparison results between different ploidy showed that the expression of three ER genes in the diploid brain tissue were significantly higher than that of the tetraploids, and the expression levels of males were higher than 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 tissue of slower growing (diploid, male) individuals. Therefore, we speculate that the ERα gene in brain tissues might have a certain inhibitory effect on the growth rate of individual fish.
                                                                                                                   
    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. This study examined the food intake changes within 24 hours after ICV, and detected the changes of appetite genes and amino acid sensing signaling pathways. 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 no significant change (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 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 agrp mRNA (P<0.05). In addition, different concentrations of histamine did not cause changes in npy and agrp mRNA expression (P>0.05). Besides, 2.0 mmol/L of histidine was no significant change the phosphorylation level of protein S6, as 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:
    Langerhans cells, one of the subtypes of Dendritic cells, are mainly distributed in mammalian skin epidermis and some mucosal tissues, and play an important role in against bacterial infection. In order to study the structural characteristics of Langerhans cells and the effect of bacterial infection on the expression of gene-related the function of Langerhans cells, CD207 positive cells were detected in the head kidney and spleen of yellow catfish by immunohistochemistry, and the ultrastructure of Langerhans cells was further observed by transmissionSelectronSmicroscope. The results of real-time quantitative PCR showed that Edwardsiella ictaluri could induce significant up-regulation of gene-related the function of Langerhans cells in the immune organs of yellow catfish. The above results indicated that the structure of yellow catfish Langerhans cells was similar to that in other vertebrates and participate in the immune response induced by E.ictaluri. This study will not only help us analyze the evolutionary characteristics of Langerhans cells in vertebrates, but provides a theoretical basis for the research of the adaptive immune system of yellow catfish.
                                                                                                                   
    Abstract:
    For a long time, whether eating persimmons can lead to gastric bezoars was controversial. The public's concerns about eating persimmons have severely restricted the development of persimmon industry. However, until now, no systematic studies have confirmed that eating persimmons can cause bezoars. Therefore, this study aimed to evaluate whether daily consumption of persimmon fruits could cause gastric bezoars. In stimulated gastric fluid system, we confirmed that the flocculation ability of tannins with food ingredients cannot been considered for its bezoars formation risk. In the animal system, our results showed that no bezoars were found in the stomach, and no intracorporal pathogenic properties were observed according to the hematological and stomach parameters after 30 days’ continuous intake of persimmon. Additionally, both volunteer tests and questionnaires in typical persimmon growing region revealed that consuming two persimmon fruits (400-500 g) daily for healthy person did not lead to gastric bezoars. Altogether, this study preliminarily confirmed that healthy adults eating two persimmons daily did not cause gastric bezoars.
                                                                                                                   
    Abstract:
    In order to definite the effect of salt pretreatment on barley seed germination and microspore culture, the salt tolerant cultivar ‘H11’ and salt sensitive cultivar ‘H30’ were used as materials and the germination rate, taproot length during the seed germination as well as the callus yield in the microspore culture stage were compared under the different salt pretreatment conditions. Meanwhile, the expression of four key genes to salt stress at the microspore stage were also investigated in the two cultivars. The results showed that the seeds and microspores of ‘H30’ were less tolerant to salt than ‘H11’ under 0 g/L NaCl and low NaCl pretreatment conditions, but under the high concentration of NaCl pretreatment (15 g/L NaCl in germination stage and 300 mg/L in microspore stage), the salt tolerance of ‘H30’ was significantly enhanced, and the germination rate, taproot length as well as callus yield with high concentration of salt stress were significantly superior to that of ‘H11’. Through the correlation analysis of germination rate, taproot length and callus yield between the two cultivars, it was found that the relative values of the differences between the two cultivars at the germination stage and the microspore stage were significantly positively correlated. Moreover, in the microspore culture stage, after 300 mg/L NaCl pretreatment, the genes HvsHSP1 and HveIF1A of ‘H30’ were significantly up-regulated in comparison with ‘H11’ under higher concentration of salt stress. It is concluded that the differences in the response of tested barley cultivars to salt pretreatment during seed germination and microspore stage may be consistent. HvsHSP1and HveIF1A of salt sensitive cultivar may be related with the response of NaCl induction in the microspore stage.
                                                                                                                   
    Abstract:
    Regulators of G-protein Signaling as a negative regulator of G protein signal transduction pathway, plays an important role in the pathogenicity and sexual reproduction of plant pathogens. Study the relationship between parasitism and RGS protein in plant pathogenic fungi will lay a theoretical foundation for further functional analysis of different types of RGS in different parasitic fungi. forty-nine filamentous fungi with the whole genome sequence were used as research objects. OrthoVenn2 was used to perform RGS homologous gene alignment, online BLASTp alignment based on the 4 RGS amino acid sequences of Saccharomyces cerevisiae, and using keyword search in NCBI database, etc., and through SMART conservative domain analysis, the results showed that there were 229 RGS in 49 fungi, and the number of RGS in each fungus ranged from 3 to 9. According to the conserve domains in RGS, above RGS protein can be divided into DEP-RGS, RGS-TM, PXA-RGS-PX, RGS, RGS-PAS-PAC, TM-RGS and other six types, of which RGS with two special conserved domains, RGS-PAS-PAC and TM-RGS, are mainly concentrated in semi-living vegetative pathogens and dead vegetative pathogens, further genetic analysis of 229 RGS proteins showed that RGS with the same conserved domain was closely related. This study found that plant pathogenic filamentous fungi have six types of RGS proteins, among which the types and quantities of RGS proteins of hemibiotrophic and necrotrophic fungi were higher than that in biotrophic fungi.
                                                                                                                   
    Abstract:
    The purpose of this study was to investigate the optimum condition of air frying for the fried-flavor fish paste/pork composite gel. The products were prepared from whole fish paste and pork by air frying. Their gel properties were evaluated in terms of textural properties, water holding capacity and moisture content. The sensory quality and colorness were also measured. The results showed that the products had the golden color and flavor and taste of fried foods after air frying, and their moisture content decreased and water holding capacity increased. In contrast, the lower temperature (60~130℃) had little effect on product quality; while at a higher temperature (160~200℃), the products’ sensory score and breaking force improved significantly, besides, both springiness and cohesiveness of products were obviously higher than unfried samples when frying time was more than 6 min; meanwhile the hardness and chewiness showed a trend of rising first and then decreasing during frying, indicating that long-time frying had a negative influence on the texture properties. In conclusion frying at 200℃ for 6min was the most appropriate condition of air frying.
                                                                                                                   
    Abstract:
    Phosphorus (P) and zinc (Zn) are both essential elements for plant growth and development. There are strong relationships between different nutrients that changing one or more nutrients in the growth medium affects the concentrations of many other nutrients in plants. Phosphorus in the form of Pi can influence the mobility and bioavailability of many metal elements such as iron, manganese, copper, and Zn. Early studies performed in various crop species indicate the existence of a negative relationship between Pi and Zn accumulation in plants. In this study, the indica hybrid rice cultivar Guangliangyou 35 and conventional japonica rice cultivar Nipponbare were treated with combined application of three Zn levels and four P levels in field trials to investigate the effects of combinations of P and Zn on rice growth and yield production, as well as the nutrient utilization. We analyzed the shoot dry weight at different growth stages, the yield and its components at mature stage as well as the P, Zn, N and K concentrations, accumulations and distributions in different organs and tissues. Results showed that the combined application of P and Zn fertilizers had synergistic effect or antagonistic effect on the rice biomass, yield production, the nutrient absorption and distribution. Under the middle- and low P levels, the proper application of Zn increased the rice biomass and yield production. However, under the high P level, the application of Zn decreased the biomass. For different rice cultivars, under different P levels, the proper application of Zn increased the yield. The significantly increased 1000-grain weight and fertility determined the increased yield under the combined application of P and Zn fertilizers. The proper combined application of P and Zn fertilizers not only increased the concentrations of P and Zn in rice plant, but also promoted the P and Zn distribution to the productive organ. Additionally, the proper combined application of P and Zn fertilizers also increased the concentrations of nitrogen (N) and potassium (K) in rice plant, as well as the distribution of N to the productive organ, which is one of the main physiological mechanisms of increased yield production under the combined application of P and Zn fertilizers.
                                                                                                                   
    Abstract:
    Soil acidification is currently increasing, but how does soil acidification affect nutrients distribution and accumulation in plant is still not clear. Effects of soil acidification or pH on soil nutrient availability, nutrients concentration and accumulation, migration and distribution in plant were measured, with aim to utilize acidic soil and its nutrients efficiently. Pot experiment was conducted with acidic red soil (pH 5.05) and Cherry tomatoes (Lycopersivon esculentum Mill) as test materials, the soil pH was adjusted with citric acid-sodium hydrogen phosphate buffer and sodium carbonate-sodium bicarbonate buffer to adjust soil pH to 4.0,5.0,6.0 and 7.0. There were 4 treatments in total, with 5 replicates for each treatment. The result shows that measured soil pH were 4.35, 4.92, 5.89, 6.85, respectively, adjusted down by 0.70, 0.13 and increased by 0.84 and 1.80 pH. Soil acidification significantly reduced the leaf area and biomass of Cherry tomato, especially the root biomass,and root to shoot ratio. Soil acidification severely inhibited the accumulation of N, P, K, Mg and Fe in roots, promoted the accumulation and distribution of Fe and Mn in stem, and Ca and Mg in leaves. Significantly decreased N, P, K, Ca, Mg and Fe accumulations and its proportion to total in root, with more N, K, Fe and Mn accumulated in stems, more P, Ca and Mg accumulated in leaves, particularly raised all whole plant Mn concentrations significantly. It concluded that the root was the most severe and sensitive part of whole tomato plant inhibited by soil acidification, as a result, most nutrients were absorbed by the roots, migration were blocked, and accumulation was significantly reduced.
                                                                                                                   
    Abstract:
    In order to reduce the power consumption, reduce the blockage of the threshing roller and improve the harvesting efficiency of the rice combine harvester, a drum-shaped rod-tooth longitudinal axial flow threshing roller was designed, and its power consumption was studied by simulation and experiment. The cylindrical rod-tooth longitudinal axial flow threshing roller with the same external dimensions was used as a control, and the total torque of the threshing roller rotating shaft was used as the test index. The comparative test based on the discrete element method was carried out. There is a significant difference in the total torque of the threshing roller rotating shaft of the structure. The total torque of the rotating shaft of the drum roller is smaller than that of the cylindrical roller, and the larger the difference is with the increase of the feed amount. A bench test for comparing the power consumption of two threshing roller structures consistent with the simulation conditions has been carried out. The results show that: within the feed rate of 0.8~1.6kg/s, it is comparable to the cylindrical roller with the same external dimensions and the roller structure threshing The roller power consumption is reduced by 5% to 15% on average. As the feed volume increases, the power consumption increases. Compared with the results under the simulation test conditions, the increasing trend of power consumption is different. Under the bench test conditions, the increase in power consumption is decreasing. Other laws are basically the same. Provide reference for the structure design of low-power rice threshing roller.
                                                                                                                   
    Abstract:
    In addition to climate, vegetation types, microbial activities and erosion, leaching is also an important factor influencing the distributions of carbon (C) and nitrogen (N) in soils with elevation. In this study, effects of leaching were discussed to explain the distributions of soil C and N in the coniferous forest along an altitudinal gradient (2600 m~3200 m a.s.l.) on Mt. Gongga. The results showed that the spatial distributions of C, N concentrations and C:N in the humified litter horizon (OH horizon) exhibited a similar decreasing trend with elevation. Since the positive correlation among concentrations of C in litters (Clit), C and N in soils in the OH horizon, the production of Clit was the main factor influencing the altitudinal distributions of C and N in the OH horizon. The obvious altitudinal trend was not observed for C, N concentrations and C:N in the mineral horizons (A, B and C horizon). The contents of C and N in the A horizon were lower in the 2781 m site, while the maximums were in this site for the B and C horizon. The contents of C and N in the rainfall were significantly lower than those in the interflow, which showed the influence of leaching on the spatial distributions of C and N. The results noted above indicated that the leaching process had a non-negligible effect on the spatial distributions of C and N in subalpine coniferous forest soils in southwest China.
                                                                                                                   
    Abstract:
    Beta-D-xylosidase (BXL) is the key rate-limiting enzyme for the complete degradation of xylan, which is the main component of hemicellulose in the plant cell wall. In this study, 16 genes encoding putative BXL proteins were identified in Brassica juncea genome. Protein physicochemical properties, gene structure and conserved motifs, chromosomal distribution and gene expression during stem swelling of BjuBXL family genes were analyzed. The results showed that 16 BjuBXL genes were classified into seven categories and formed two subfamilies according to the phylogenetic tree analysis. Subfamily 1 included BjuBXL1~5 and Subfamily 2 included BjuBXL6 and BjuBXL7. BjuBXL1-1~1-4 were closely related to AtBXL1, which was involved in the Arabidopsis cell wall metabolism and plant development. Multiple alignments of the 16 BjuBXL protein sequences revealed that all of them contained the conserved WGR and KH motifs that are associated with substrate binding and conserved amino acids at two key active sites for xylose hydrolysis. Sixteen BjuBXL genes coded 769 to 984 amino acids, which corresponding 83.37 to 109.32 kD molecular weight protein. The grand average of hydropathicity (GRAVY) score of the 16 BjuBXL proteins was predicted from -0.273 to -0.049, indicating these proteins are hydrophilic. According to gene structure and conserved motifs analysis, subfamily 1 of BjuBXL contained 5~11 exons and subfamily 2 contained 3~5 exons, and all the BjuBXL proteins contain ten conserved motifs. Chromosomal distribution analyses showed that 7 BjuBXL genes were located in 5 chromosomes of A subgenomes and 8 BjuBXL genes are located in 4 chromosomes of B subgenomes. The expression patterns of 16 BjuBXL genes during stem swelling was obtained from the RNA-seq data, 9 BjuBXL genes showed noticeable expression changes during the stem swelling process, while other 7 BjuBXL genes were nearly not expressed. The expression of BjuBXL1-1 and BjuBXL 1-2 were found notably correlated with stem swelling. Furthermore, real-time PCR results revealed that the transcriptional levels of BjuBXL1-1and BjuBXL1-2 were up-regulated during stem swelling and were significantly higher in the inner pith (P2~P4) than in regions of the outer pith of swollen stem (P1). Our results suggest that BjuBXL1-1 and BjuBXL1-2 may play an essential role in the inner pith cell wall metabolism during stem swelling. This study laid a foundation for further investigations of the function of BXL family genes in B. juncea var. tumida.
                                                                                                                   
    Abstract:
    Water-soluble nanometer fluorescent carbon points were synthesized in one step by "microwave method", then the silicon dioxide was grafted on the surface of carbon points by “sol-gel” method through tetraethyl orthosilicate (TEOS) as the cross-linking agent and phenyl ether methyl cycloazole as the template molecule. The polymer C-dot@MIP with good application prospects in trace detection of pesticide residues was obtained after the template molecules were washed off. Experimental results showed that the minimum detection limit calculated by 3σ/K was 0.93 μg/mL, and the recoveries of blank and standard spiking sample were not exceeding 25 percent.
                                                                                                                   
    Abstract:
    In this paper, the method of extraction and transient transformation of oil palm leaf protoplasts was established. Protoplasts were isolated from leaves of oil palm by 30 g/L cellulase and 8 g/L macerozyme for 3.5 h, and collected by centrifugation at 2000 rpm/min for 5 min at 4°C. Moreover, the dual plasmid transient co-expression system was optimized using green fluorescent protein (GFP) and red fluorescent protein (RFP). The best transformation efficiency was the obtained when the plasmids were mixed with oil palm protoplasts with the mass ratio of 8: 1, heat shocked at 45 °C for 20 min after placed on ice for 30 min, and incubated at room temperature in the dark for 30 min with equal amount of PEG/Mg2+ (200 g/L PEG 4000 and 100 g/L MgCl2). Finally, the protoplast isolation and transient expression system provides a new method for the functional verification of the genes form oil palm.
                                                                                                                   
    Abstract:
    In order to explore the effects of different plant height, center of gravity height and basal stem traits on lodging resistance of rice, In this study, 533 core rice germplasms were used as experimental materials, and 10 traits were analyzed by correlation and path analysis under two cultivation modes of pot culture and field culture.The results show that the first internode wall thickness and basal stem breaking-resistant strength of the low-plant rice have synergy on the lodging index.The improvement of lodging resistance traits of low-plant rice should focus on the first internode stem thickness and wall thickness. The lodging of high-plant rice is more affected by plant height and height of centre of gravity and the improvement of lodging resistance should be concentrated in the second internode stem thickness.The improvement of lodging resistance of rice germplasm with different plant heights can be achieved by enhancing the bending strength of the base. This study would provide an important reference for the improvement of lodging resistance in different rice plants.
                                                                                                                   
    Abstract:
    A field experiment was conducted in 2011 to study the effects of phosphorus (P) fertilizer application on the phosphorus fractions and microbial diversity of rice - rape crop rotation. Two treatments, NK (-P) and NPK (+P), were selected for the experiment. The soil layer was divided into 0~10、10~20、20~30 and 30~40 cm for sampling and analysis. Soil available P, total P and organic P were determined by conventional analytical methods. Chemical continuous extraction method was used to determine the inorganic P fractions in the soil samples, and Illumina-miseqpe250 platform was used for high-throughput sequencing of surface soil (0~10 cm) microorganisms. The results showed that, compared with the CK (-P treatment), long-term application of P fertilizer (+P) could significantly increase the content of total P, inorganic P and available P in each soil layer, but the organic P content did not increase significantly. From the perspective of available P content in soil layer, P content in soil layer of 0~10 cm and 10~20 cm could be significantly increased by application of P fertilizer, but the effect on the bottom layer of 20~30 cm and 30~40 cm was not obvious. Compared with -P treatment, long-term application of P fertilizer reduced the Alpha of microbial community diversity and changed the structure of microbial community. At the level of phylum, the dominant bacteria were Chloroflexi, Acidobacteria and Proteobacteria. The relative abundance of Chloroflexi and Acidobacteria were increased, while that of Proteobacteria decreased. Ascomycota and Basidiomycota were the dominant phylum, the relative abundance of Ascomycota decreased and that of Basidiomycota increased. Compared with CK, although the application of P fertilizer caused a significant decrease in the number of bacteria and fungi in the layer soil in each taxa, the relative abundance of the dominant flora also decreased from the perspective of the genus level. The results of redundancy analysis showed that the content of Al-P and Fe-P was closely related to the abundance of various bacteria and fungi. It could be seen that long-term phosphorus deficiency would induce an increase in the number of microorganisms to activate soil nutrients, and a sufficient supply of phosphorus fertilizer would meet crop nutrient requirements and maintain the dynamic balance of soil microbial communities. Therefore, it is necessary to optimize the application of P fertilizer in the entire crop rotation system to promote the activation and release of soil phosphorus, thereby reducing the amount of P fertilizer and improving its recovery rate.
                                                                                                                   
    Abstract:
    Xanthomonas campestris belong to Gram-negative bacteria, which mainly harm cruciferous vegetables and economic forests such as 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 have been no reports on the physical and chemical properties and characteristics of secreted proteins of Xanthomonas. This study uses the secreted protein sequences of X. campestris B100, X. campestris pv. campestris str.8004, and X. campestris CN14 with the published genome-wide sequence as the basic data, and uses Protscale, SMART, TargetP 2.0 Server, and other organisms. Informatics analysis software analyzes the physicochemical properties, conserved domains, and transit peptides of the above-secreted proteins. The results show that there are no obvious rule between the theoretical isoelectric point of secreted proteins in X. campestris and the length of amino acids. The average 44.73% of the protein is Unstable protein, with an average of 83.21% of the total protein, the average hydrophilicity is less than 0, which is a hydrophilic protein. At the same time, 12 of the secreted proteins of each X. campestris have an obvious conserved domain, and all secreted The protein is localized at S (signal peptide), and the predicted probability distribution of the transit peptide is also relatively even. This study lays a solid theoretical foundation for the in-depth analysis of the function of X. campestris secreted proteins.
                                                                                                                   
    Abstract:
    The moisture content of citrus is one of the key factors affecting the subsequent storage and processing of citrus. In order to detect the moisture content of citrus, the visible/near infrared transmission spectroscopy was used to detect the moisture content of satsuma orange. Differential processing, multivariate scattering correction, standard normal variate,SG convolution smoothing and MinMaxScaler are used and compared. At the same time, the Competitive adaptive reweighted sampling algorithm was used to extract the characteristic wavelengths, and then the partial least squares regression model(PLS), BP neural network model and least squares support vector machine (LSSVM) model based on citrus moisture content were established. The results show that the LSSVM model with 359 wavelengths obtained by CARS screening using the SNV preprocessed spectrum is the best predictor. The correlation coefficient and root mean square error of the correction set are 0.9375 and 0.0086, respectively. The square root errors are 0.8316 and 0.0120, respectively. The results show that the visible/near infrared spectroscopy technique is feasible to detect the water content of satsuma orange.
                                                                                                                   
    Abstract:
    In order to explore the application technology of fertilizer and pesticide reduction, a two-factor and three-level experiment was designed to compare the effects of different fertilizer and pesticide reduction combinations on the occurrence and yield of major diseases and pests in rice. The results revealed that the reduction of fertilizer tended to reduce the incidence of disease and insects, whereas the reduction of pesticides gave rise to a tendency to increase the incidence of disease and insects. The occurrence of rice sheath blight, fourth generation rice planthopper, and rice leaf borer could be significantly affected by the reduction of fertilizer. By contrast, the occurrence of rice sheath blight, third - and fourth-generation rice planthopper, and rice leaf borer were significantly affected by the pesticide reduction. However, They both had no significant effect on the occurrence of rice blast, rice false smut, and rice borer. When the fertilizer reduction is approximately 30%, there is a significant effect on yield, leading to the harvest yield reduction of 10.29%. When the reduction of fertilizer is less than 20%, compared with the control treatment, the harvest yield of green additive alternative treatment and biological pesticide alternative treatment increased 0.38% and 2.49%, respectively. Biological pesticide and green additive alternative treatment can be used as technical measures for reducing the number of chemical pesticides.
                                                                                                                   
    Abstract:
    The concept of a modern vertical farm was proposed in 1999. Theoretically, it has many advantages over traditional soil-based agriculture. In order to analyze and summarize the development and research status of vertical farms during the past two decades, this article used “vertical farm” and related terms as key words to search literatures from three databases, including CNKI, SCOPUS and Web of Science (WoS). Bibliometrics quantitative analysis was conducted with 184 selected literatures. The research progress was compared in China and internationally. By sorting and categorizing the literature, the research hotspots of vertical farms, as well as their research methods, were summarized. Based on that, the technical and economic feasibility were further analyzed. The results reveal that during the last decade the research on the vertical farm has accelerated, but the overall number of documents is still small, and only 25 relevant documents have been found in the WoS core collection database which represent research of high quality. The starting time of research on vertical farms in China and globally is similar. However, after the introduction of the concept in China, the popularity has declined, accounting for a low proportion of publications in China's core journals (only 10.6%). While international research has maintained a continuous upward trend since 2008 and continues to accelerate. And Nearly a quarter of international researches come from WoS core collection database. Results also presents a research trend in interdisciplinary fields. The research hotspots are mainly in the three aspects: technology integration, economy and feasibility, and ecological and environmental benefits. Research methods cover experimental research, case studies, mathematical modeling analysis, and simulation software analysis. At present, the key technologies involved in vertical farms are basically mature and there are no major obstacles. The key factors restricting its development are the cost-effectiveness and the uncertainty of ecological and environmental impacts, which need to be studied timely. With the continuous improvement of technical level and the proper selection of development strategies, the development prospect of vertical farms is very optimistic.
                                                                                                                   
    Abstract:
    The effects of four Culture medium on the symbiosis of different varieties of soybean and AM fungi (Rhizophagus irregularis) were studied by pot culture. The difference between black ink and trypan blue staining methods and the application of the magnified grid line and the five-class methods in mycorrhizal symbiosis structures detection were also compared in this research.The results show that vermiculite and soil (V: V = 4: 1) are more conducive to the infection of AM fungi with soybean. The arbuscular abundance, hypha density and vesicle abundance in this culture substrate are significant higher than others, so it can be used as the best culture substrates for soybean and AM fungi symbiosis. For large-scale mycorrhizal symbiosis structures detection, ink staining and the magnified grid line method are the best methods in currently.
                                                                                                                   
    Abstract:
    The kiwifruits soft rot is the most serious disease during the storage and transportation of kiwifruits, which causing great economic losses. In this study, the pathogenic fungus causing kiwifruit soft rots were isolated and identified by examining the morphological and microscopic characteristics, combined with the results of pathogenicity testing and ITS (internal transcribed spacer) sequencing, and the inhibitory effect of carvacrol on kiwifruits soft rot was further evaulated. Two species, Botryosphaeria dothidea and Phomopsis vaccinii, were identified as the main pathogens causing kiwifruit postharvest soft rots, the other three species followed by Botrytis cinerea, Fusarium proliferatum and Alternaria alternata. Carvacrol had significant antifungal activity against eight soft rot pathogens,especially for B. dothidea and Phomopsis sp.,which half effective concentration (EC50) were 12.57 and 9.09 μL / L, respectively. Simultaneously, carvacrol effectively reduced the incidence of soft rot in kiwifruit under simulatedsales environment, which was only 50.17% compared with the control group, and had no significant effect on fruit quality(P > 0.05). Therefore, carvacrol has great potential to control soft rot of postharvest kiwifruit.
                                                                                                                   
    Abstract:
    The popular used rice cultivar Guangliangyou 35 and conventional japonica rice cultivar Nipponbare were treated with combined application of three Zn levels and four N levels in field trials. We analyzed the shoot dry weight at different growth stages, the yield and its components at mature stage as well as the N and Zn concentrations, accumulations and distributions in different organs and tissues. Results showed that the combined application of N and Zn fertilizers had synergistic effect on both the rice biomass at the early growth stage and the yield production at the mature stage. The combined application of N and Zn fertilizers had significant synergistic effect on rice panicle numbers. The significantly increased panicle numbers determined the increased yield under the combined application of N and Zn fertilizers. The combined application of N and Zn fertilizers not only increased the concentrations of N and Zn in rice plant, but also promoted the N and Zn distribution to the productive organ (spikelet), which is one of the main physiological mechanisms of increased yield production under the combined application of N and Zn fertilizers.
                                                                                                                   
    Abstract:
    To provide more insight in the characteristics of the cutan in the S5 and its environmental significance, the mineralogy and geochemical composition of the cutan and matrix soil in the S5-1pedon at the Wugong section on the southern Chinese Loess Plateau (CLP) was investigated. The broad band between 400-800 cm-1 in the Raman spectrum of the dark cutan was attributed to the groups of Fe and Mn hydroxide/oxide. Enrichment of Mn and free iron (Fed) in the cutan verified the presence of Fe-Mn cutan in the S5-1 pedon which signified a periodic reduction under waterlogged conditions during the pedogenesis of S5-1 pedon on the southern CLP. The low permeability of S5-1 pedon as a result of lessivage of clay fraction characterized by high bulk density and low total porosity made the development of a seasonal perched water table possible. It provided favorable environmental conditions for the formation of Fe-Mn cutan. However, the low Mn/Fe ratio in the cutan suggested that the separation and accumulation of iron and manganese in the S5-1 pedon was not up to the level of typical Fe-Mn cutan from subtropical regions. Silicate minerals in the Fe-Mn cutan was was almost identical to the matrix soil. The difference of chemical weathering between the cutan and the matrix soil reflected by the Fed/Fet ratio was not epitomized by the mineralogical composition. While the S5-1 developed a subtropical climate prevailed on the southern CLP was further corroborated by the occurrence of Fe-Mn cutan.
                                                                                                                   
    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:
    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:
    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:
    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.
    Display Method:
    2015,34(4):108-113, DOI:
    [Abstract] (1552) [HTML] (0) [PDF 1.06 M] (8826)
    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] (1875) [HTML] (0) [PDF 976.50 K] (6920)
    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] (1774) [HTML] (0) [PDF 1.58 M] (5537)
    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] (2045) [HTML] (0) [PDF 1.21 M] (4328)
    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] (2286) [HTML] (0) [PDF 1.07 M] (4230)
    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] (1378) [HTML] (0) [PDF 4.01 M] (4095)
    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] (1107) [HTML] (0) [PDF 3.41 M] (3932)
    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] (1510) [HTML] (0) [PDF 930.13 K] (3777)
    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] (1185) [HTML] (0) [PDF 912.59 K] (3592)
    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(2):139-144, DOI: 1000-2421(2014)02-0139-06
    [Abstract] (1294) [HTML] (0) [PDF 968.56 K] (3419)
    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(06), DOI:
    [Abstract] (755) [HTML] (0) [PDF 8.30 M] (3344)
    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.
    2010,29(3):363-368, DOI: 1000-2421(2010)03-0363-06
    [Abstract] (2497) [HTML] (0) [PDF 11.41 M] (3337)
    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(01):12-17, DOI: 1000-2421(2014)01-0012-06
    [Abstract] (1502) [HTML] (0) [PDF 944.55 K] (3333)
    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.
    2015,34(3):134-141, DOI:
    [Abstract] (1177) [HTML] (0) [PDF 1.42 M] (3316)
    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.
    2014,33(2):15-21, DOI: 1000-2421(2014)02-0015-07
    [Abstract] (1714) [HTML] (0) [PDF 980.62 K] (3305)
    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.
    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] (1056) [HTML] (0) [PDF 1.05 M] (3155)
    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] (1149) [HTML] (0) [PDF 914.54 K] (3134)
    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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