• Volume 35,Issue 3,2016 Table of Contents
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    • >园艺.林学
    • Genetic identification of Jincheng sweet oranges with SRAP markers

      2016, 35(3):1-5.

      Abstract (1538) HTML (0) PDF 2.88 M (2144) Comment (0) Favorites

      Abstract:80 pairs of SRAP primer were used to analyze the genetic relationship among 16 Jincheng(Citrus sinensis Osbeck) germplasms from Chongqing area.The results showed that the genetic relationship between different Jincheng species was very close.In the PCR amplification,only 30 pairs of primers (37.5%) were polymorphic.56 polymorphic bands were obtained,with an average of 1.87 band each pair of primers.Results of cluster analysis showed that the genetic relationship between Baleng Cheng and Changye Cheng was more far than that between other types.The closest relationship was between BDQ222 and BDM221,and between BDQ222 and S26.SRAP markers have a high applicability in identifying plant types with close genetic relationship.By sequencing and analyzing polymorphic fragments,we speculate that some polymorphic fragments may be associated with variation of some traits of Jincheng.It will provide basis for future exploring Jincheng germplasm.

    • Cytological mechanisms of the elite seedless Ponkan accessions

      2016, 35(3):6-11.

      Abstract (1104) HTML (0) PDF 6.83 M (2153) Comment (0) Favorites

      Abstract:The cytological mechanisms of the elite seedless Ponkan accession were systematically studied through comparing with its maternal parent Jiangxi Ponkan and E-gan No.1. Male gamete fertility,self-incompatibility and embryo development were investigated. The results showed that male gamete of Jiangxi seedless Ponkan developed abnormally and the pollen fertility of the elite seedless Ponkan was significantly lower than that of the control. Meanwhile the abnormal meiosis percentage of pollen mother cell was severely higher than that of the control. Morphological and anatomical structure of microspore mother cell of the elite seedless Ponkan was different from that of the control. The seedless Ponkan accession had self-compatibility and its pollen tubes grew downward through the style normally. Embryo abortion occurred at early developmental stage causing the seedlessness of the elite seedless accession. The 3rd week after pollination was the critical period to observe the embryo abortion. Seed numbers in fruit did not change significantly by self-pollination or cross-pollination. Embryo abortion is responsible for the elite seedless Ponkan accession.

    • Evaluating fruit qualities of different sweet cherry cultivars

      2016, 35(3):12-16.

      Abstract (1974) HTML (0) PDF 920.54 K (2586) Comment (0) Favorites

      Abstract:To select the best sweet cherry cultivar in Weining County,Guizhou Province,the external/internal quality parameters of five sweet cherry cultivars were quantified and comprehensively evaluated.The results showed that 12 indices including fruit weight,content of soluble solid,content of soluble sugar,and ratio of soluble sugar to titratable acid etc,varied highly among five cultivars.There were significant correlations between the fruit weight and the content of soluble solid,content of soluble sugar,or ratio of soluble sugar to titratable acid,or ratio of content of soluble solids to titratable acid; between the content of soluble solid and fruit diameter; between the ratio of content of soluble solids to titratable acid and ratio of content of soluble sugar to titratable acid,or content of soluble sugar.The cumulative contribution of three principal components was 93.55% and all the 12 indices were involved.Based on the comprehensive evaluation model of fruit quality,the first principle component played a key role in fruit quality.The best cultivars were Brooks and Spar kerry,followed by Santina.The least ones were Black pearl and Yanyang.

    • Processing pattern of a novel leaf mustard hybrid with hau cytoplasmic male sterility

      2016, 35(3):17-23.

      Abstract (1277) HTML (0) PDF 956.31 K (1909) Comment (0) Favorites

      Abstract:A novel leaf mustard hybrid with hau cytoplasmic male sterility was used to breed a leaf mustard cross with strong heterosis (0912A×X2).The basis of heterosis was studied.The safety standards of nitrate and nitrite in the pickled process of 0912A×X2 were investigated.Results of orthogonal experimental design showed that nitrate content and nitrite content of 0912A×X2 was in the lowest level of optimization marinated process mode.Results of early marinated ( 0-15 d ) showed that the optimal combination of low level of nitrate was under the condition at 30℃ of pickled temperature,75 mg/kg of sodium sulfite dosage,3% salt mass fraction,0.02 g/kg of Vc dosage.Optimized low level of nitrite was at 10.7℃ of pickled temperature,50 mg/kg of sodium sulfite dosage,1% salt mass fraction,0.01 g/kg of Vc dosage.Optimal low level of nitrates of late pickled ( 16-31 d ) was at 25℃ of pickled temperature,0.0 mg/kg of sodium sulfite dosage,1% salt mass fraction,0.03 g/kg of Vc dosage.Optimized combination of low level of nitrite was at 10.7℃ of pickled temperature,50.0 mg/kg of sodium sulfite dosage,1% salt mass fraction,0.01 g/kg of Vc dosage.It is indicated that the use of new mustard leaf mustard hybrid bred with cytoplasmic male sterility has obvious heterosis and pickled processing quality.It will provide a theoretical basis for developing sources of material and processing leaf mustard hybrids in the future.

    • >Plant protection
    • Genome-scale prediction and analysis of secreted proteins of Fusarium oxysporum f. sp. melonis

      2016, 35(3):24-29.

      Abstract (1958) HTML (0) PDF 989.85 K (2879) Comment (0) Favorites

      Abstract:Genome-scale prediction of FOM(Fusarium oxysporum f.sp.melonis) secretome was firstly performed by combining different bioinformatic softwares,including SignalP,TMHMM,WOLFPRT,TargetP,big-PI Fungal Predictor,and SecretomeP in this study.Of the 26 811 FOM protein sequences,1 145 sequences (4.3%) were predicted to be classically secreted proteins and 8 471 sequences (31.6%) might be secreted in a non-classical manner.The 1 145 secreted proteins were characterized with 100 to 600 amino acids,and the length of the signal peptides was concentrated between 17 to 22 amino acids.Of the 1 145 classically secreted proteins,a total of 605 proteins were functionally annotated to be involved in carbohydrate metabolic process,transport process,hydrogen peroxide catabolic process and biosynthetic process.Among the 1 145 classically secreted proteins,277 proteins (24.2%) were predicted to be CAZymes.

    • Spatial distribution pattern of cereal aphids and the dynamic tracingof aphid parasite in Zhongning County,Ningxia,China

      2016, 35(3):30-37.

      Abstract (1099) HTML (0) PDF 1.04 M (2245) Comment (0) Favorites

      Abstract:We studied the spatial distribution pattern of cereal aphids along with the dynamic tracking of aphid parasite, in Zhongning County, which would provide scientific basis for comprehending the occurrence regularity and prevention of the aphids in arid area of northwest district. Employing the checkerboard-type investigation in 5 places, we analyzed and simulated the distribution and temporal dynamics of aphids and its parasite with aggregation indices and gray relational degree in different landscape structures. There were 10 kinds of Aphidiidae and 1 kind of Aphelinidae in the local field. The population of cereal aphids (Sitobion avenae,Schizaphis graminum) and the parasites mainly showed aggregation distribution, fitting the negative binomial distribution. The aggregation distribution indices increased along with the increasing of the density itself. The aggregate of S. avenae other than S. graminum was affected remarkably by the complexity of field. The spatial patterns of the aphids changed periodically from diffusion to assembly. The distribution of the parasite was related to the aphids densities, and the tracking effect to S. avenae was stronger than to S. graminum. When tested by Blackith’s method, the aggregation was induced by environmental factors, such as climate, growth period and so on, and if the density of S. avenae and S. graminum was more than 5.57 and 8.26, per plant respectively, the aggregation depended on the interaction between the creature themselves and the environment. Aphidius avenae, A. gifuensis and A. sichuanensis had significant trace relationships with the aphid populations.

    • >Resources and environment
    • LysM receptor LcLRK1 from Lotus corniculatus involved in the arbuscule formation

      2016, 35(3):38-48.

      Abstract (1260) HTML (0) PDF 8.04 M (2881) Comment (0) Favorites

      Abstract:A LysM receptor LcLRK1 gene possibly involved in Myc-factor perception was isolated from Lotus corniculatus. The full-length of LcLRK1 gene was isolated from L. corniculatus by using the degenerate primers and RACE PCR strategies.The structure of LcLRK1 gene was analyzed with bioinformatics.The expression profiles of LcLRK1 gene were investigated in variant tissues from L. corniculatus after inoculation Rhizophagus irregularis.A recombinant plasmid harboring ProLcLRK1∶∶GUS reporter was constucted to localize LcLRK1 in the roots of L.corniculatus.The LcLRK1 gene was knock-down with RNA interference.The results showed that LcLRK1 gene,encoding a LysM receptor kinase,was comprised of three extracellular LysM domains,a transmembrane domain and intracellular kinase domain.LcLRK1 gene was up-regulated in roots at early stage of AM symbiosis and the transcripts of LcLRK1 were mainly present in the root epidemis and root hairs.The knock-down of the LcLRK1 gene significantly decreased AM fungal colonization.In RNAi lines,the infection rate and arbuscule numbers were strongly reduced compared to that in the controls.The LcLRK1 gene may participate in the perception of Myc-factor and down-regulation of LcLRK1,affecting the formation of AM fungal arbuscule.

    • Screening and identification of the interacting protein with a RLKs protein Nip43 in Astragalus sinicus

      2016, 35(3):49-53.

      Abstract (1277) HTML (0) PDF 1.87 M (2433) Comment (0) Favorites

      Abstract:The S-TKs domain of Astragalus sinicus gene nip43 was cloned into pGBKT7 and used as a bait plasmid.17 original positive candidate clones were obtained with yeast two-hybrid screening method.One positive clone encoding an EPN protein out of importance was identified through sequencing the cDNA inserts.EPN is an adaptor in the polymerization of clathrins.The critical interaction domain of EPN with Nip43 was determined as ENTH/ANTH domain.Results of real-time qPCR showed that epn gene was involved in the early process of root nodulation.

    • Antioxidation and symbiotic nitrogen fixation phenotype of ohrB gene in Rhizobium leguminosarum

      2016, 35(3):54-60.

      Abstract (1322) HTML (0) PDF 1.04 M (2230) Comment (0) Favorites

      Abstract:Through homologous recombination, a Rhizobium leguminosarum ohrB mutant was constructed,and its antioxidation and symbiotic nitrogen fixation phenotypes were studied.The growth ability of the ohrB mutant was the same as the wild type under free-living condition.However,cells of the ohrB mutant were sensitive to CuOOH,H2O2 and NaClO.The ohrB mutant was highly sensitive after the short exposure to CuOOH.The results of quantitative real-time PCR showed that the expression of ohrB was not stimulated by exogenous H2O2.The transcription of other antioxidant genes in the ohrB mutant strain was not changed.The ohrB mutant had normal nitrogenase activity and the same colonization ability in the pea rhizosphere compared to the wild type.However,the ohrB gene in 7-day-old pea bacteroids was expressed significantly higher than that in free-living cells.The competition nodule ability of ohrB mutant was reduced compared to that of the wild type.It is indicated that ohrB is essential in antioxidation and competition of nodule ability,playing an important role in antioxidation and symbiosis.

    • Effects of 5406 antibiotic fertilizer on greenhouse of continuous cropping Capsicum annuum

      2016, 35(3):61-65.

      Abstract (1320) HTML (0) PDF 1.05 M (2168) Comment (0) Favorites

      Abstract:The effects of 5406 antibiotic fertilizer on the soil pH,enzyme activity,fertility of soil,yield production and fruit quality under the greenhouse of a five years’ continuous cropping Capsicum annuum were studied.The results showed that after applying 5406 antibiotic fertilizer,the production,average fruit weight,Fe content of fruit,Mg content of fruit and Ca content of fruit was increased by 44.63%,23.96%,65.97%,8.56% and 2.67%,respectively.The contents of crude protein and phosphorus had no significant differences compared to the control group.Vitamin C content decreased slightly.The maximum activity increase of soil invertase,urease,and catalase was 37%,10%,8%,and 20%,respectively.The content of organic matter,alkali-hydrolyzable nitrogen,rapidly available kalium and rapidly available phosphorus was 9%,4%,3% and 33%,respectively.The soil pH value was increased as well.5406 antibiotic fertilizer can significantly improve yield production,fruit quality,and soil fertility.It has great application value.

    • Carbon cycling in three vegetation ecosystems in Dongting Lake wetland

      2016, 35(3):66-71.

      Abstract (1239) HTML (0) PDF 956.26 K (2180) Comment (0) Favorites

      Abstract:The plant biomass,soil CO2 and CH4 emission rates of wetland were determined and used to analyze the carbon cycling between the atmosphere,plants and soil of three wetland plants ecosystems in Dongting Lake.The results showed that the air traffic flow vegetation carbon of herbs,trees and aquatic plant systems was 6.02,6.00 and 2.01 t/(hm2·a).The plant layer carbon flux to the soil was 2.21,1.04 and 0.73 t/(hm2·a).The soil carbon flux to the atmosphere was 2.36,2.14 and 1.29 t/(hm2·a).There was carbon sink function in the carbon cycle in the atmospheric,vegetation and soil subsystem of three kinds vegetation ecosystem,which the net system productivity was in the order of the herbs (5.87 t/(hm2·a))>tree plant (4.90 t/(hm2·a))>aquatic systems (1.45 t/(hm2·a)).The content of this study only involved with the carbon cycle of wetland vegetation systems atmosphere,plants,soil between and did not involve with wetland hydrological geochemical processes in the carbon cycle.The comprehensive analysis of effects of the carbon cycle wetland system of the entire process,wetlands hydrogeochemical process on wetland carbon cycle should be the focus of further studies.

    • Chemical forms of phosphorus in the water and sediment from Pengxi River in the Three Gorges Reservoir

      2016, 35(3):72-76.

      Abstract (1214) HTML (0) PDF 1.10 M (2275) Comment (0) Favorites

      Abstract:Chemical forms of phosphorus in the water and sediments from Pengxi River in the Three Gorges Reservoir were investigated from Jan 2015 to May 2015.The results showed that the content of total phosphorus,dissolved total phosphorus and soluble reactive phosphorus was 0.066-0.129 mg/L,0.033-0.118 mg/L and 0.013-0.094 mg/L,respectively.All three chemical forms and their relative ratio varified spatially and temporally.The concentration of dissolved total phosphorus and soluble reactive phosphorus was negatively correlated with the concentration of Chla.The total phosphorus in the sediments was 0.6-1.0 mg/g.The value was close to the content in sediment from Yangtze River (Wanzhou region) and smaller than that in soils from Pengxi River.The phosphorus concentration in sediment samples from Shuangjiang Bridge profile was higher than that of the other three profiles because of human activity.The result of SMT sequential extraction analysis showed that inorganic phosphorus was the main chemical form of phosphorus.Apatite phosphorus was the second predominant species while organic phosphorus and non-apatite phosphorus were the minor compositions.The ratio of non-apatite phosphorus to total phosphorus in the sediments from upper profile (Quma,Gaoyang) was higher than that from downstream (Shuangjiang Bridge).Since the bioavailability of non-apatite phosphorus was higher than that of the other two chemical forms,the contribution of phosphorus from sediment,especially from upstream sediment,to the growth of aquatic organism like alga etc.could not be neglected.

    • Preparation and characterization of a ratiometric fluorescent pH probe based on gold nanoclusters

      2016, 35(3):77-82.

      Abstract (1164) HTML (0) PDF 2.55 M (2479) Comment (0) Favorites

      Abstract:A red-emitting gold nanoclusters was prepared by using the bovine serum albumin(BSA) and a ratiometric fluorescent pH probe was prepared by using the BSA-capped AuNCs and FITC.Results showed that the fluorescence intensity of FITC was gradually enhanced with pH changing from acid to alkali condition,while the fluorescence intensity of AuNCs was constant.The probe displayed a fine linear relationship towards pH,with the corresponding linear regression equation of Y=1.72X-8.8 and the relative standard deviation of 0.994 when the pH changed from 5.5 to 8.0.The probe had good reversibility when the pH was between 6.0 and 9.0.In addition,the PK15 cells were cultivated with the pH probe.Result of MTT assay showed that the pH probe was almost no toxicity to cells.

    • Isolation and identification of endophytic fungus Devriesia lagerstroem and its promoting effect on Dendrobium candidum growth

      2016, 35(3):83-88.

      Abstract (1275) HTML (0) PDF 5.42 M (2112) Comment (0) Favorites

      Abstract:Two hundred and four fungal isolates were obtained from stems and leaves of different plants.One endophytic fungal isolate 24L-4 was selected by pathogenicity test on Chinese cabbage.Isolate 24L-4 was identified as Devriesia lagerstroem based on its morphological characteristics and sequences of internal transcribed spacer and 18S ribosomal DNA.Isolate 24L-4 was inoculated on Dendrobium candidum tissue cultures and pot seedlings,respectively,with non-inoculated seedlings as the control.The results showed that the seedling height,leaf width,stem diameter and dry weigh were significantly enhanced by 33.3%,65.7%,27.3% and 45.1%,respectively,in the tissue cultures.Similar results were observed in the pot experiment with increase percentages by 104.0%,83.9% and 114.7% for the stem diameter,fresh weight and dry weight,respectively.The hyphae and microscierotia-like structures of isolate 24L-4 were found in the root epidermal and cortex of D. candidum.These results indicated that isolate 24L-4 had excellent growth promoting effect on D. candidum.

    • >Animal science.Veterinary medicine
    • Distribution and expression of gonadotropin-inhibitory hormone (GnIH) indigestion system and trachea of Luchuan male piglets

      2016, 35(3):89-93.

      Abstract (1115) HTML (0) PDF 8.08 M (2254) Comment (0) Favorites

      Abstract:Immuhischemistry (IHC) and semi-quantitative RT-PCR were used to study the distribution and expression of gonadotropin-inhibitory hormone (GnIH) in the digestion and respiratory system of 30-day-old Luchuan male piglets in this research.The IHC results showed that the GnIH immune positive cells distributed in both digestion and respiratory system,such as torus pyloricus,duodenum,ileum,colon,liver,esophagus,filiform papillae,submandibular gland and trachea,but the GnIH-ir cell morphology and sizes were diverse.The results of semi-quantitative RT-PCR suggested that the GnIH mRNA was moderately expressed in the colon and submandibular gland,lowly expressed in the torus pyloricus,filiform papillae and ileum,and not expressed in the other organs.

    • Identification of core promoter of porcine AZ1 gene and transcriptional activity of haplotypes 

      2016, 35(3):94-100.

      Abstract (1083) HTML (0) PDF 1.02 M (2288) Comment (0) Favorites

      Abstract:In the study,the core region of porcine AZ1 gene promoter was identified through the Dual-luciferase Reporter Assay System.SNPs and haplotypes were analyzed in Lantang and Landrace pig populations,and the transcriptional activities of different haplotypes were measured.The results showed that the region of ??453 /+79 nt was the core region of the promoter.Eight SNPs were found in the two populations,and they were ??713 T>C,??584 A>C,??476 G>A,??365 T>C,??348 C>T,??294 G>C,??288 T>G,and ??234 T>C.Richer SNPs were found in the Lantang pigs.In the Landrace population,GG and GT genotypes were found at ??288 locus,and no heterzygotes were detected in the other seven loci.The frequencies of predominant haplotypes of LTH1 (TAGCCGTC) and LTH2 are 0.526 and 0.166 respectively in Lantang population,and the Landrace-H haplotype (TAGTCGGT) was predominant in the Landrace population.The activity of LTH1 was stronger than that of LTH2 and Landrace-H.The SNPs of ??234 T>C,??365 T>C and ??288 T>G might be the causative mutations that change the different activities of the haplotypes.

    • Effects of different dietary protein sources on growth performance,amino acid composition and antioxidant ability of loach,Misgurnus anguillillcaudatus fingerling

      2016, 35(3):101-107.

      Abstract (1090) HTML (0) PDF 1015.16 K (2601) Comment (0) Favorites

      Abstract:A feeding trial was conducted to investigate effects of fish meal (FM),soybean concentrate (SC),canola meal (CM) and a combination of these protein sources at ratio 1∶1∶1 (Mix) on growth performance,whole amino acid compositions and antioxidant ability of loach,Misgurnus anguillillcaudatus fingerling.A total of 1 200 loach with an average initial weight of 35.0± 0.1 mg were fed on the test diets for 30 d in a flow-through fresh water system.The results showed that the body weight gain (BWG) of FM and Mix groups was significantly higher than those of SC and CM groups.Moreover,feed intake (FI) of the fingerling in FM was higher than that of the plant protein groups.Whole body lysine and valine concentrations in essential amino acid of the fingerling fed on CM were significantly lower than those fed on FM.In the term of antioxidant enzyme activities,the fingerling in SC group had higher glutathione peroxidase activity and lower superoxide dismutase activity compared with loach in the FM,CM and Mix diets groups.In conclusion,fish meal is suitable protein source for loach fingerling.

    • Effects of hypoxia on cardiomyocyte apoptosis and activity of antioxidant enzymes in Megalobrama amblycephala heart

      2016, 35(3):108-113.

      Abstract (1065) HTML (0) PDF 4.45 M (2238) Comment (0) Favorites

      Abstract:In the present study,effects of hypoxia on cardiomyocyte apoptosis and activity of antioxidant enzymes in the Megalobrama amblycephala heart were studied.The results showed that hypoxia caused changes of heart structure and mitochondrial damage by using HE staining and electron microscope observation.Moreover,hypoxia induced cardiomyocyte apoptosis and the Bcl-2 mRNA expression changes by using TUNEL and quantitative real-time PCR methods.In addition,the results revealed that moderate hypoxia could result in the decrease of the MDA content and SOD activity of the heart mitochondria extracted by sucrose gradient centrifugation.

    • >Food science and agricultural engineering
    • Property and characterization of polyphenol oxidase in red-fleshed peach skin

      2016, 35(3):114-121.

      Abstract (1269) HTML (0) PDF 1.73 M (2148) Comment (0) Favorites

      Abstract:The polyphenol oxidase in red-fleshed peach skin was extracted in Tris-HCl buffer and purified by ammonium sulfate precipitation and column chromatography.One pure single band was obtained using electrophoresis.According to the Michaelis-Menten constant,the optimal substrate of the PPO was pyrogallol.The optimal temperature and pH of the PPO at 420 nm was 45℃ and 7.0-7.5,respectively.PPO was more stable in neutral pH environment and below 55℃.Circular dichroism (CD) spectrum,fluorescence spectroscopy,and dynamic light scattering were used to characterize the structures of the PPO.Result of CD spectrum showed that the secondary structure of PPO contained 50.61% α-helix,32.47% β-folded,10.83% β-corner and 6.21% random coil.Result of fluorescence spectroscopy showed that the maximum emission wavelength of PPO was 352 nm.The intensity of fluorescence was 133.9,indicating that the fluorophore was in a polar hydrophilic environment.Result of dynamic light scattering showed that the particle size distribution was concentrated at 255 nm,indicating that the PPO was in a gathering state.

    • Analyzing the mechanical characteristics of cutting Hypophthalmichthys molitrix head

      2016, 35(3):122-127.

      Abstract (1089) HTML (0) PDF 1.23 M (2101) Comment (0) Favorites

      Abstract:The silver carp was used to study mechanical characteristics of cutting fish head.The head-cutting machine of freshwater fish was designed to provide an important theoretical basis.Statistical analyses of basic signs parameters of the head of the fish body including length,width and thickness were made to determine the freshwater fish head orientation and to snout the fish head to fish back line for locating datum.To determine the shear force,the important factors affecting the shear effect of freshwater fish head-cutting including fish refrigerating time,the sliding cutting angle,placement of fish were studied with the orthogonal experiment.Results showed that the optimal condition for freshwater fish head-cutting was that fish was horizontally placed after 6 h frozen.The thickness of curved cutting knife used is 2.0 mm.At this time to has The minimum shear force of head-cutting was 186.7 N under the optimal condition.The surface level of fish head-cutting was smooth.There was no obvious defect of fish flesh with head-cutting.

    • A method of identifying the navigation path of rapeseed direct seeder

      2016, 35(3):128-133.

      Abstract (1655) HTML (0) PDF 6.37 M (2059) Comment (0) Favorites

      Abstract:In practical applications,the complexity of the farmland environment including weather and rice stubble noise has resulted in bad effect of vision navigation of rapeseed direct seeder.To solve this problem,a method of identifying the vision navigation of rapeseed direct seeder based on wavelet transform and improving random sample consensus (RANSAC) was proposed.The original image grayed was wavelet transformed to highlight the macro profile of the navigation path.The feature of work area and non-work area with high-contrast in the work images of rapeseed direct seeder was used to find the feature points of navigation path through ROI sliding windows.The improved RANSAC with correction of pre-test and post-process was used to distinguish inner points and outer points in the set of navigation path feature points,and the navigation path parameters was calculated by least squares in the set of inner points.Results of field experimental tests showed that the algorithm could detect stably and accurately the navigation path with the correct rate of 96.7%.The processing time for each frame was less than 31.0 ms.It will provide technical support for identifying the vision navigation of rapeseed direct seeder.

    • Analysis and testing research of key working parts of the half-feed peanut picker

      2016, 35(3):134-139.

      Abstract (1251) HTML (0) PDF 1.39 M (2427) Comment (0) Favorites

      Abstract:To self-develop half-feed peanut picker,the composition and working principle of the picker,the configuration mode of the picking roller,picking movement process and the structural parameters of the picking plate was introduced.The reasonable structure and parameters of picking roller and picking plate was confirmed by theory and experiment.Using peanut breakage rate,unpicking rate,impurity rate,and total loss rate as the index,the configuration mode of picking roller,structure and parameters of picking plate was studied.Results showed that when the picking roller was the intersection and parallel configuration,the breakage rate and impurity rate were the maximum.When the picking roller was the tangent and parallel configuration,the unpicking rate was the maximum and the impurity rate was the minimum.When picking roller was the tangent and parallel configuration or gradually tight angle configuration,the breakage rate was lower.The unpicking rate of the arc plate was a little higher than that of the straight board plate and bend plate.The bigger the rotational speed of the picking roller,the greater the breakage rate and impurity rate to the straight board plate,bend plate.The radian of the plate obviously affected the breakage rate and impurity rate.The smaller the radian,the higher the breakage rate and the lower the unpicking rate.When the plate radian is 70 ° and the arc radius is 35 mm,the total loss rate is the minimum.By theoretical analysis and picking performance test,the tilt configuration method is adopted on picking roller to clamping chain.The gradually tight type angle configuration method is adopted between the double picking rollers.The picking plate is adopted in the backward-arc type with the plate radian of 70 ° and the arc radius of 35 mm.

    • Designing an unmanned multi-rotor spray aircraft

      2016, 35(3):140-144.

      Abstract (1391) HTML (0) PDF 1.91 M (3042) Comment (0) Favorites

      Abstract:An unmanned multi-rotor spray aircraft was designed to solve the problems existed in southern China including the complex operational environment of agriculture,scattered distribution of farmland,low efficiency of manual spraying operations.This aircraft has advantages of high efficiency,low labor intensity,good adaptability to operating environment.The vehicle frame adopts full carbon fiber structure,hardened aluminum connecting parts. The structure is stable and reliable.It can keep working 15 minutes under the condition of continuous operation with the load of 10 kg.It will provide a reference for spray,forestry,forest monitoring.

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