Abstract:Objective To obtain Chinese hamster ovary cell line (CHO-K1) which can stably express antigen epitope fusing VP1 protein of swine O-type foot-and-mouth disease virus (FMDV), and prepare subunit vaccine.Method A recombinant gene RP1 containing FMDV antigen epitope and its VP1 gene sequence was designed, synthesized and cloned into expression vector pCDH-CMV-MCS-EF1-Puro. The constructed recombinant plasmid was co-transfected into HEK-293T cells with helper plasmids PLP1, PLP2 and PLP3 to obtain recombinant lenti virus HIV-RP1. CHO-K1 cells were infected by the harvested virus solution, and the monoclonal cell lines were obtained by screening. The expressing RP1 positive cell line named CHO-K1-RP1 was obtained by indirect immunofluorescence assay (IFA) and Western blot identification. The CHO-K1-RP1 was passed on continuously for 30 generations, and the same number of cell samples were collected every five generations for Western blot identification.Result IFA results showed that the cells expressing RP1 emitted green fluorescence, while the blank control had no green fluorescence. Western blot results showed that a clear band was observed at about 55 kU. The above results indicated that the fusion protein was successfully obtained. Female BALB/c mice were immunized with subunit vaccine prepared by mixing equal volumes of fusion protein and adjuvant. The antibody titer identification results showed that after the second immunization, foot-and-mouth disease (FMD) subunit vaccine group and FMD commercial inactivated vaccine group had no significant difference at antibody levels, but both were significantly higher than those of control (P<0.05).Conclusion The subunit vaccine constructed in this study can effectively stimulate the immune response in mice, which provides a reference for the development of a new vaccine against FMD in pigs.

Abstract:Objective Somatic cell nuclear transfer (SCNT) is widely used in agriculture, biomedicine and other fields, but the low cloning efficiency restricts the application and promotion of this technology. The purpose of this study was to explore the relationship between the DNA methylation levels of imprinted genes (XIST, H19) and cloning efficiency.Method Fourteen cell clone groups were obtained by culturing the same pig-derived ear fibroblasts, and were used as the donor cells for SCNT experiments. We statistically compared the blastocyst rates and DNA methylation levels of XIST and H19 gene regulatory regions for each sac of cloned embryos produced with each clone group as donor cells. We analyzed the correlation between the DNA methylation levels of differentially methylated regions for XIST and H19 genes and the blastocyst rates of cloned embryos.Result The DNA methylation level of XIST gene of blastocysts obtained from clone group 1 as donor cells was the highest (65.04%) and the blastocyst rate was the lowest (8.6%). The DNA methylation level of XIST gene of blastocysts obtained from clone group 14 as donor cells was the lowest (16.68%) and the blastocyst rate was the highest (38.2%). The correlation analysis showed that there was a strong negative correlation between the XIST gene methylation level and the blastocyst rate (|r|=0.8125>0.8). The highest and lowest DNA methylation levels of H19 gene A side were 5.12% and 0.61% respectively. Correlation analysis showed that there was only a very weak correlation between the DNA methylation level of H19 gene A side and blastocyst rate (|r|=0.1647< 0.3). The highest and lowest DNA methylation levels on the G side of H19 gene were 90.92% and 72.69% respectively. Correlation analysis showed that there was only a low correlation between the DNA methylation level on the G side of H19 gene and the blastocyst rate (0.3<|r|=0.3098<0.5).Conclusion The lower the DNA methylation level of XIST gene, the higher the blastocyst rate of the clone group. The research results provide a basis for improving the efficiency of pig SCNT embryonic development and improving the existing pig SCNT technology system.

Abstract:Objective To establish triplex RT-qPCR detection technique for rapid screening and diagnosis of bluetongue virus (BTV), epizootic hemorrhagic disease virus (EHDV) and Palyam serogroup virus (PALV) infection.Method NS3 gene of BTV, NS1 gene of EHDV and VP7 gene of PALV were used as target genes to design three sets of primers and probes for the establishment of a triplex RT-qPCR assay. The sensitivity, specificity and repeatability of this assay were evaluated, meanwhile different BTV, EHDV, PALV serotype strains isolated in China and their corresponding positive blood samples, as well as reference strains of 24 BTV serotypes and six EHDV serotypes were used to verify detection effects of the assay.Result The amplification efficiencies of the triplex RT-qPCR assay were all more than 90%, and the copy number detection limits of in vitro transcribed ssRNAs were all low to 10 μL^-1, which was equivalent to those of single plex RT-qPCR assay for each virus. There was no cross reaction with akabane virus, peste des petits ruminants virus, foot-and-mouth disease virus and bovine ephemeral fever virus. The intra-assay and inter-assay variable coefficients of Ct value were all less than 2%. The established triplex RT-qPCR successfully detected viral strains belonging to 24 BTV serotypes, six EHDV serotypes and three PALV serotypes, indicating that this assay possessed remarkable group specificity. The established triplex RT-qPCR assay could effectively detect the positive blood samples collected from animals infected by BTV, EHDV and PALV, and the results were consistent with those of monoplex RT-qPCR assay.Conclusion The triplex RT-qPCR detection assay for BTV, EHDV and PALV has good sensitivity, specificity and repeatability, and can be used for the simultaneous diagnosis and screening of these three viruses in clinical samples.

Abstract:Objective To study the growth of rice seedlings as well as absorption and transport of zinc (Zn) and copper (Cu) under different silicon (Si) application levels.Method ‘Wandao 71’ was used as material through water cultivation to study the biomass, zinc and copper contents and accumulation of rice seedlings under different silicon fertilizer levels of 0 (CK), 30, 60, 90, 120, 150 mg·L^-1, respectively.Result The leaf number, plant height and root length of rice seedlings were all higher than those of the control, and the biomass (fresh weight) of rice shoots and roots increased over the control by 5.44%-52.81% and 4.83%-42.49% respectively. The leaf number, plant height, root length and above-ground biomass were the highest in 90 mg·L^-1 SiO₂ treatment. Zn and Cu net absorptions of rice root increased over the control by 5.79%-77.43% and 6.51%-44.96%, respectively. The Zn transport coefficients of 60 and 90 mg·L^-1 SiO₂ treatments increased over the control by 10.91% and 38.18% respectively, meanwhile those of Cu increased by 8.70% and 26.09% respectively. The contents of Zn and Cu in rice shoot increased with the increase of SiO₂ concentration, reached the peak value at 90 mg·L^-1 SiO₂ concentration, and then began to decline with the increase of SiO₂ concentration.Conclusion Considering the factors of rice growth index, biomass, and absorption of Zn and Cu, 90 mg·L^-1 SiO₂ treatment is the best Si fertilizer level for microelements of Zn and Cu absorption in the present study.

Abstract:Objective To clarify the change law of soluble solid contents and volatile flavor substances of sweet corn (Zea mays L. saccharata Sturt.) after harvest under different storage temperature and time, and lay a foundation for the research on the quality characteristics of sweet corn after harvest.Method Three sweet corn cultivars of ‘Aofulan’, ‘Wangchao’, and ‘Guangliangtian 27’ were used as materials. The soluble solid contents of three cultivars were measured by a handheld digital sugar meter, and the volatile flavor components of sween corns under normal temperature (room temperature) and low temperature (4 ℃) storage conditions were detected and analyzed by headspace solid-phase microextraction through gas chromatography-mass spectrometry. Furthermore, multivariate statistical analysis was used analyze the volatile flavor components of different cultivars. Result Compared with normal temperature storage, the content of soluble solid of sweet corn decreased slowly under low temperature storage. Total 58 and 59 kinds of volatile substances were detected under normal and low temperature storage conditions respectively, mainly alkanes and esters. There were certain differences in the types of volatile flavor substances among different cultivars under different storage conditions. There were the same eight volatile flavor substances among different cultivars under different storage conditions, including 3,8-dimethyldecane, 3-methylundecane, dodecane, tetradecane, 3-methylpentadecane, ethyl hexadecanoate, nonadecane and n-hexadecane. Partial least squares discriminant analysis (PLS-DA) showed that nine and ten key volatile substances with variable importance projection (VIP)>1 have been identified under normal and low temperature storage respectively. The common key volatile substance of ‘Aofulan’ under normal and low temperature storage was (+)-cycloclofalene, and that of ‘Wangchao’ was eicosane.Conclusion Both storage temperature and time affect the content of soluble solids and the types and contents of volatile substances in sweet corn.

Abstract:Objective To investigate the effects of arbuscular mycorrhizal (AM) fungi inoculation on sunflower (Helianthus annuus) growth and salt ion accumulation under different types of saline-alkali stress, and provide basic data and technical support for the utilization and bioremediation of different types of saline-alkali land.Method A greenhouse pot experiment was conducted to investigate the effects of AM fungi Funneliformis mosseae on mycorrhizal colonization rate, biomass, nutrient uptake, C∶N∶P stoichiometry, Na⁺ absorption, photosynthesis and membrane permeability of sunflower under different types of salt-alkali stress (CK, NaCl, NaCl+Na₂SO₄, NaCl+NaHCO₃).Result Three types of saline-alkali stress decreased the mycorrhizal infection rate of sunflower inoculated with F. mosseae by 29.53% to 47.31%. Three types of saline-alkali stress all inhibited the growth of sunflower to a certain extent, and the order of the inhibition effect was NaCl+Na₂SO₄>NaCl+NaHCO₃>NaCl. Inoculation with AM fungi increased the total dry weight of sunflower under salt-alkali stresses of NaCl, NaCl+Na₂SO₄ and NaCl+NaHCO₃ by 19.58%, 42.15% and 60.35% respectively. Inoculation of AM fungi increased the shoot P contents of CK, NaCl and NaCl+NaHCO₃ treatments by 82.50%, 71.11% and 74.47% respectively, and increased the root P contents of CK and NaCl+NaHCO₃ treatments by 61.54% and 88.37% respectively. Inoculation of AM fungi significantly decreased the C∶P and N∶P in shoots and roots of CK and NaCl+NaHCO₃ treatments and the C∶P and N∶P in shoots of NaCl treatment. The shoot and root Na⁺ accumulations of NaCl+NaHCO₃ treatment increased by 33.76% and 82.25% with AM fungi inoculation respectively, and the root Na⁺ accumulation of NaCl+Na₂SO₄ treatment increased by 74.20%. Inoculation of AM fungi increased transpiration rates (Tr) of NaCl and NaCl+NaHCO₃ treatments by 11.67% and 10.12% respectively, and increased stomatal conductance (Gs) of NaCl+NaHCO₃ treatment by 20.00%. The net photosynthetic rate (Pn) in shoots under three types of salt-alkali stress showed an increasing trend. The membrane permeability of NaCl+NaHCO₃ significantly decreased by 51.49% with AM fungi inoculation.Conclusion AM fungi can alleviate the toxic effect of saline-alkali stress on sunflower growth to a certain extent, but its inoculation effect is significantly different among different types of saline-alkali stress.

Abstract:Objective To investigate the effects of continuous cropping of Andrographis paniculata on soil bacterial diversity and community structure.Method Sequencing analysis of samples from continuous cropping group (rhizosphere soil of A. paniculata continuous cropping for five years) and control group (uncultivated natural soil with the same texture as the soil around A. paniculata continuous cropping for five years) were performed using 16S rRNA gene high-throughput sequencing technology. The differences in richness, diversity and community structure of soil bacteria from two groups were analyzed.Result The analysis results of α diversity index showed that the bacterial richness indices (Chao1 index and Observed species index) in the soil of continuous cropping group were significantly lower than those of the control group (P<0.05), and the diversity indices (Shannon index and Simpson index) in the soil of continuous cropping group were lower than those of the control group, but the differences were not significant. Principal coordinates analysis and molecular variance analysis of community structure between groups showed that continuous cropping of A. paniculata significantly changed soil bacterial community structure (P<0.05). A total of 2769 operational taxonomic units were detected from the soil samples of two groups, belonging to 47 phyla and 885 genera. Continuous cropping of A. paniculata obviously changed the structure distribution of soil bacteria at the phylum and genus level. At the phylum classification level, 11 bacterial phyla including Acidobacteria, Proteobacteria, Bacteroidetes, Patescibacteria and etc. were the main bacterial communities in two groups. Compared with the control group, the relative abundance of Proteobacteria and Acidobacteria in the continuous cropping group increased by 21.97% and 46.33% respectively (P<0.05), while the relative abundance of Patescibacteria reduced by 68.99% (P<0.05). At the genus classification level, the relative abundance of 10 dominant bacterial genera changed significantly (P<0.05). Among them, compared with the control group, the relative abundance of the beneficial bacteria Flavobacterium and Haliangiumin in the soil of continuous cropping group reduced by 78.40% and 54.55% respectively, while the relative abundance of the plant pathogenic bacterium Burkholderia-Caballeronia-Paraburkholderia in the soil of continuous cropping group increased by 804.17%.Conclusion After five years of A. paniculata continuous cultivation, the level of soil bacterial richness and diversity decreased. At the same time, the relative abundance of beneficial bacteria significantly reduced, while the relative abundance of pathogenic bacteria significantly increased, causing a change in the bacterial community structure. The above-mentioned changes broke the original soil microecological balance, which may be one of the important reasons for A. paniculata continuous cropping obstacles.

Abstract:目的 预测、挖掘和分析涉及赤桉Eucalyptus camaldulensis低温胁迫应答的miRNA，为研究其调控赤桉低温胁迫应答的分子网络奠定基础。方法 采用高通量测序对低温处理组和对照(CK)组的赤桉组培苗茎尖进行小RNA测序。以miRBase21.0、Rfam14.1和巨桉E. grandis基因组为参考数据库，利用Bowtie、miREAP和miRDeep2等软件进行miRNA预测，使用RNAfold对预测到的miRNA前体进行二级结构的折叠；采用psRNATarget预测靶基因，通过DEGSeq包分析差异表达的miRNA，并对它们进行GO注释和KEGG富集分析。结果 在赤桉中，共预测到隶属于54个家族的392个已知miRNA和97个新miRNA；其中，CK组共预测到282个已知miRNA，65个新miRNA；低温处理组共预测到329个已知miRNA，51个新miRNA。挖掘到80个在低温处理下显著差异表达的miRNA，包括55个上调和25个下调。GO基因功能注释和KEGG富集分析的结果表明，这些差异表达miRNA可能通过参与代谢通路、次生代谢物的生物合成、细胞膜的改变、信号转导和生物调节等响应低温胁迫。此外，还挖掘到25个可能与ICE1-CBFs-COR通路有关的miRNA。结论 借助高通量测序和生物信息学软件初步得到了低温胁迫下差异表达的赤桉miRNA，为进一步分析这些miRNA在赤桉低温胁迫中的分子功能提供一些参考。

Abstract:Objective To analyze the effects of three important factors of soil nutrients, planting years and methods (understory and no understory) on oligosaccharide content which is one of the core index of Morinda officinalis quality, provide the theoretical and data supports for cultivation of M. officinalis which is one of the “Four Southern Herbs” in China.Method This study selected eighteen no understory planting sites in the genuine producing area of M. officinalis in Deqing County, Guangdong Province. Soil samples and M. officinalis samples of different growth years were collected by random multi-point sampling method. The contents of soil nutrients and oligosaccharides in M. officinalis flesh root were determined to analyze the relationships of soil nutrient contents, growth years and oligosaccharides content of M. officinalis. In addition, samples in understory and no understory planting sites were collected to explore the quality differences of M. officinalis by principal component analysis.Result The pH value was highly negatively correlated with sucrose content (P<0.01) and positively correlated with oligosaccharide content (P<0.05). Total phosphorus, available phosphorus and available potassium in soil were positively correlated with the contents of 1-kestose and nystose (P<0.05). The sucrose content of 3-year-old M. officinalis was significantly higher than those of other growth years, and 1-kestose content of 4-year-old M. officinalis was significantly higher than that of 2-year-old M. officinalis. The understory M. officinalis showed better quality than that of no understory.Conclusion Improving the contents of available P and available K in soil can improve the quality of M. officinalis. The quality of 4-year-old M. officinalis is the best in our study. Understory planting can improve the quality of M. officinalis.

Abstract:Objective The response of wheat spectrum to powdery mildew stress based on hyperspectral technique was studied in order to determine the infection grade of powdery mildew quickly.Method The visible-near infrared spectra of wheat leaves were collected by fiber optic spectrometer combined with a integrating sphere and a leaf clip. The spectrum fitting SPAD (SF-SPAD) value was used to reflect the chlorophyll content, so as to preliminarily determine the infection of powdery mildew. Spectral sensitivity analysis was performed using PROSPECT model to identify sensitive bands. We combined dimension reduction by principal component analysis (PCA) and support vector machine (SVM) modeling to realize binary classification of spectral data. The infection degree of wheat was graded according to the percentage of disease spots determined by the PCA-SVM binary classification model.Result The SF-SPAD value increased with the increase of leaf order from bottom to top. Spots with SF-SPAD values less than 0.90 were disease spots, while spots with SF-SPAD values above 1.05 were good spots. The spectral sensitivity analysis identified the sensitive bands as 440-500 and 540-780 nm in the visible region, and therefore reduced the data dimension. The relationship between the infection grade (R) and the percentage of disease spots was determined as R₁: 0-30%, R₂: 30%-50%, R₃: 50%-70%, R₄: 70%-100%. The model established in this assay was suitable when the number of tested plants was above 20.Conclusion The monitoring model based on SF-SPAD and spectral PCA-SVM binary classification can accurately and rapidly determine the infection of wheat powdery mildew and the infection grade, reduce the number of samples, reduce the workload of detection on the ground, and improve the detection efficiency. The monitoring model is an intelligent monitoring technology which is practical, simple and easy to popularize.

Abstract:Objective The traditional image recognition method relies on manual design features, is time-consuming and labor-intensive, has large number of network model parameter and has low recognition accuracy rate. The goal was to solve these problems in traditional method for identifying citrus fruit infected with Huanglongbing.Method Firstly, we collected the images of citrus fruit with Huanglongbing, and performed data enhancement modes such as flip, rotation, affine, and Gaussian disturbance. Further, we used the Mixup algorithm to establish a linear relationship between samples to enhance the robustness of the model for identifying data samples. Then, we transfered the prior knowledge on the ImageNet data set of Xception network, and proposed a citrus Huanglongbing fruit recognition model of X-ResNeXt model based on Mixup algorithm and convolutional neural network. Finally, the momentum gradient descent optimization method was used to reduce the impact of shocks and effectively accelerate the convergence of the model to the local optimum.Result The accuracy rate of the X-ResNeXt model trained on the data set after data enhancement was 91.38%. After optimization with transfer learning, the training time reduced by 432 s, and the accuracy rate of the model increased to 91.97%. Combined with the enhancement of Mixup mixed data for further training, the accuracy rate of the model improved to 93.74%. Finally, the momentum gradient descent method was used to optimize the model convergence, and the final model accuracy rate reached 94.29%, which was 3.98% and 1.51% higher than Inception-V3 and Xception networks, respectively.Conclusion In the case of a small amount of data, reducing the complexity of the model and transfering existing prior knowledge will help to improve the performance of the model. The Mixup mixed data enhancement method is beneficial to improve the adaptability of the model to identify image samples of citrus fruit with Huanglongbing and improve model performance. The X-ResNeXt model is superior to the classic recognition model in terms of accuracy rate and recall rate, and can provide references for the high-precision, rapid and non-destructive identification of citrus Huanglongbing.

Abstract:Objective To evaluate the effects of spraying defoliation and ripening agent on cotton before harvest using unmanned aerial vehicle (UAV).Method Four cotton cultivars including ‘Jinmian 18#’, ‘Beiquan 9#’, ‘Zhijin 13#’ and ‘Hexin 47#’ were sprayed defoliation and ripening agent with the spraying volume of 22.5 L·hm^-2 at 30 days before harvest by UAV. Aritificial spraying with an electric backpack sprayer was used as cantrol at the the spraying volume of 450 L·hm^-2. Droplet coverage rates in the canopies of four cotton cultivars were tested. The defoliation rates and boll opening rates were investigated at the 4th, 7th, 14th and 21st days after the application. The fiber qualities and yield components (boll weight and lint percentage) of four cotton cultivars were detected.Result The droplet coverage rates of four cotton cultivars showed a rule that coverage of the upper canopy was significantly higher than that of the middle and lower parts of the canopy. The higher the plant height was, the lower the droplet coverage rate of the middle and lower canopy was. Except for the boll opening rate of artificial spraying treatment on ‘Hexin 47#’, the defoliation rates and boll opening rates of other treatments met the requirements of machinary harvesting. The fiber quality and yield components (boll weight and lint percentage) of four cotton cultivars were not affected by the type of sprayers.Conclusion The UAV can be applied to spray defoliation and ripening agent before cotton harvest.

Abstract:Objective On account of history environmental factors such as temperature and humidity in farrowing houses, based on the data of a farrowing house of a modern pig farm in Guangdong Province, the temperature prediction model of pig house was studied based on time series and multivariate models.Method The effects of relative humidity, carbon dioxide concentration, oxygen concentration and other environmental factors on temperature prediction in pigsty was evaluated by statistical prediction of missing part environmental factors. Data preprocessing was carried out for the time series of piggery temperature to filter out the error value and missing value. The time series model was used to construct the temperature prediction model of piggery based on gated recurrent unit (GRU). Based on extreme gradient boosting (XGBoost), the temperature prediction model of missing value importance degree in pigsty was established using multivariate model. The prediction model was applied to predict the temperature of a farrowing house of an intensive pig farm in Guangdong Province, and compared with the recurrent neural network (RNN) model and back propagation neural network (BPNN) model.Result Comparing the predicted value with the measured value, root mean square error (RMSE), mean absolute error (MAE) and mean absolute percent error (MAPE) of the GRU model were 0.25 ℃, 0.19 ℃ and 0.65% respectively, while RMSE, MAE and MAPE of the XGBoost multicomponent model were 1.21 ℃, 0.71 ℃ and 2.50% respectively. For temperature prediction based on time series models, GRU model showed better prediction effect. The XGBoost model was better in temperature prediction for multivariate model.Conclusion The CRU model used in this study plays an early warning role on the temperature change of the farrowing house in time dimension, and the influence degree of various environmental parameters on temperature is also determined, which provides a reference for the fine regulation of the breeding environment.

Abstract:Objective To solve the whole area coverage problem of agricultural robot in digital ecological farm with path repetition rate as the optimization target.Method Firstly, the obstacles in the raster map were expanded and rectangular partitioning was performed and the partitions were merged. Then, the improved ant colony algorithm was used to calculate the traversal order among partitions, and the improved breadth first search (BFS) algorithm was used to calculate the connecting path between the end point and the starting point between partitions. By this way, the whole area coverage of robot could be achieved. The improvement schemes of the two algorithms were as following: The selection and crossover operators of genetic algorithm were improved by artificial immune algorithm and particle swarm optimization algorithm respectively. The improved selection and crossover operators, mutation operator of original genetic algorithm and ant colony algorithm were combined to improve the pheromone updating method of traditional ant colony algorithm. The dynamic function was established to simplify the path planned by BFS algorithm.Result The simulation results showed that the number of iterations and path length of the improved ant colony algorithm were 83.1% and 4.8% less than those of the traditional ant colony algorithm. The path repetition rate of the improved ant colony algorithm and the improved BFS algorithm was 56% of the traditional ant colony algorithm and BFS algorithm, and the agricultural robot could achieve 100% coverage of farmland.Conclusion This study provides a solution for agricultural robots to perform the whole area coverage in digital ecological circular farm with complex environments.

Abstract:Objective Longan shelling is the key process in longan deep processing. Aiming at the problems of low manual shelling efficiency, large mechanical shelling damage and poor pulp integrity, the flexible double roller shelling device was designed.Method The way of first breaking the shell and then using the flexible roll shelling was proposed to break the shell according to the physical and mechanical properties of typical longan fresh fruit. The critical components of the longan shelling machine including the breaking shell mechanism, the feeding pressure plate and the peeling roll were designed. The cutting depth of the shell breaking cutter and the gap between the shelling flexible rollers were adjustable. Taking Guangdong ‘Chuliang’ longan fresh fruit as the research object, orthogonal test analysis was carried out. Three parameters, incuding the roller gap, roller speed and shell break size, were selected as experimental factors. The success rate of shelling, the loss rate of shelling and the integrity coefficient of pulp were selected as indexes to perform optimization test.Result The convenient and adjustable gap between rollers could meet the shelling processing of longan after classification, and the shelling device had good adaptability to longan with different fruit sizes. The roll gap had a significant effect on shelling performance. With the increase of roller gap from 3 mm to 5 mm, the integrity of longan pulp after shelling became worse, and the loss rate increased from about 7% to 18%. The ranking of influence was roller gap > roller speed > shell break size. When the roller gap was 3 mm, the rotation speed was 13.5 r/min and the shell break size was approximately 90°, the machine got the best shucking effect.Conclusion This study provides a reference for further processing of lantern shaped pulp obtained by mechanical shelling of longan and other flexible fruits and the parameter optimization of shelling machine.