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25 January 2023, Volume 35 Issue 1 Previous Issue    Next Issue
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Crop Science
Animal Science
Horticultural Science
Plant Protection
Environmental Science
Food Science
Quality and Safety of Agricultural Products
Biosystems Engineering
Agricultural Economy and Development


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Contents 2023, 35(1):  0-0.  Abstract ( 98 )   PDF (2053KB) ( 379 )   Related Articles | Metrics

Crop Science

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Performance of trehalose treatment on yield formation and quality of post-flowering heat-stressed weak gluten wheat Shengxuan No.6 WANG Ben, LI Yuxing, LI Zhe, JIANG Fengyi, HUANG Zhenglai, FAN Yonghui, ZHANG Wenjing, MA Shangyu 2023, 35(1):  1-9.  DOI: 10.3969/j.issn.1004-1524.2023.01.01 Abstract ( 1506 )   HTML ( 1189085194 )   PDF (1236KB) ( 732 )   To determine the effect of treatment with trehalose on yield formation and quality of post-flowering heat-stressed weak gluten wheat, the experiment was conducted in 2020-2021 at the National Agricultural Science and Technology Park in Huainan, Anhui Province, with high-quality weakly glutenous wheat Shengxuan No. 6 as the test material. The experiment was carried out at heading stage (T1), flowering stage (T2) and 10 days after flowering stage (T3). Treatment concentrations of trehalose were 5 mmol·L-1 (C1), 10 mmol·L-1 (C2), and 15 mmol·L-1 (C3), with equal amounts of water sprayed as control, high temperature treatment was applied 15-19 d after flowering. The analysis showed that trehalose treatment increased grain yield of wheat under post-anthesis high temperature stress and improved the dry matter allocation and proportion of grains, and the dry matter allocation and proportion of nutrient organs displayed a decreasing trend after trehalose treatment, while the transport amount and rate of dry matter stored in nutrient organs before flowering to the grains and the accumulation of dry matter after flowering showed an increasing trend. With the increasing concentration of trehalose treatment the starch content of the grains also showed an increasing trend, and no significant difference was found between the two treatment levels of C2 and C3 in various treatment periods, however, the level of C3 was slightly higher than C2. Trehalose treatment reduced the content of grain albumin, globulin and gliadin protein, but the content of glutenin was higher than CK, and the glutein/gliadin value of the grains under trehalose treatment was significantly higher than CK. The trehalose-treated kernels were significantly different from CK in terms of protein content, wet gluten content, formation time, stabilization time and sedimentation value. The greatest improvement in grain yield and quality was achieved by spraying C3 concentration of trehalose at T1 period compared with CK under the study conditions of this experiment. Figures and Tables | References | Related Articles | Metrics

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Injury effect of high temperature stress on growth and development of rice and its defense countermeasures YOU Cuicui, HE Yizhe, XU Peng, HUANG Yaru, WANG Hui, HE Haibing, KE Jian, WU Liquan 2023, 35(1):  10-22.  DOI: 10.3969/j.issn.1004-1524.2023.01.02 Abstract ( 1539 )   HTML ( 756 )   PDF (1223KB) ( 787 )   Under the background of global warming, high temperature weather occurs frequently, heat injury have become one of the main problems that seriously affect high and stable yield of rice. The research progress on the effects of high temperature stress on the growth and development, spikelet fertility, reactive oxygen species accumulation and membrane damage, photosynthesis, endogenous plant hormones, yield and quality of rice were summarized. The defense countermeasures against high temperature hazards of rice had been proposed, including breeding of heat-resistant rice varieties, rational adjustment sowing date, strengthening of water and fertilizer management in paddy fields, rational application of plant growth regulators and other substances. To provide scientific support for the development of heat-resistant rice cultivation and breeding of heat-resistant rice varieties, the future research direction of rice heat injury was prospected. References | Related Articles | Metrics

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Clonging and expression analysis of TaPAT1-2D gene in wheat DONG Feiyan, SONG Jinghan, ZHANG Huadong, WU Haotian, LI Yaqian, LIU Mengwei, GAO Chunbao, FANG Zhengwu, LIU Yike 2023, 35(1):  23-32.  DOI: 10.3969/j.issn.1004-1524.2023.01.03 Abstract ( 437 )   HTML ( 88 )   PDF (3345KB) ( 621 )   As a plant-specific transcription factor, the GRAS (GIBBERELLIN-INSENSITIVE, repressor of ga1-3 and SCARECROW) gene family plays a vital role in plant growth and stress tolerance. To further explore the gene involved in response to Fusarium head blight of wheat in this family, the research screened out the differentially expressed gene TaPAT1-2D(TraesCS2D02G198200.1) from the Fusarium graminearum spore-induced wheat transcriptome sequencing data, and conducted its full-length cloning, bioinformatics analysis, expression pattern analysis, subcellular localization, and transcription activation studies. The results of bioinformatics analysis showed that the exon sequence of TaPAT1-2D was 1 668 bp, encoded 555 amino acids, and had a molecular weight of around 61.34 ku. Its protein sequence comprised a typical GRAS functional domain and was phylogenetically related to rice OsCIGR2 (LOC_Os07g39470.1). In the promoter region, TaPAT1-2D contained some plant hormone response elements and light-responsive elements including methyl jasmonate response elements, auxin response elements, abscisic acid response elements, Etc. Quantitative real-time PCR results revealed that expression level of TaPAT1-2D gene was up-regulated at 72 h after inoculating with F. graminearum spore liquid in four distinct resistants, indicating that this gene was involved in response to Fusarium head blight. Agrobacterium tumefaciens-mediated transient expression was carried out in tobacco and the result showed that TaPAT1-2D protein was localized in the nucleus and cell membrane. The yeast transcription activation experiments verified that the protein could self-activate transcription. This study laid the foundation for studing TaPAT1-2D gene’s function. Figures and Tables | References | Related Articles | Metrics

Animal Science

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Expression profiles of CHH2 gene in redclaw crayfish Cherax quadricarinatus and its role in ovarian development CHEN Leran, ZHENG Jianbo, JIA Yongyi, CHI Meili, LI Fei, CHENG Shun, LIU Shili, LIU Yinuo, JIANG Wenping, GU Zhimin 2023, 35(1):  33-40.  DOI: 10.3969/j.issn.1004-1524.2023.01.04 Abstract ( 487 )   HTML ( 6 )   PDF (2069KB) ( 548 )   To study the role of crustacean hyperglycemic hormone gene (CHH) in the ovarian development of Cherax quadricarinatus, sequence of CHH2 gene was identified based on transcriptomic data, and the basic characteristics were analyzed by bioinformatic. qRT-PCR was used to detect the expression level of CHH2 in different tissues and ovarian development stages. The results showed that CHH proteins were highly conserved among crustacean species, and they had high homologies with 66.84%. The tissue distribution at transcriptional level displayed that CHH2 was hardly to be detected in hepatopancreas, and was detected at low level in muscle, gills, heart and intestine, while highly expressed in ovary. In addition, CHH2 was expressed in all stages of ovarian development and exhibited an abnormal expression pattern with the lowest expression level at mature stage. On the other hand, CHH2 expression was significantly reduced in ovarian tissues after ESA treatment and E2 injection. Furthermore, VTG was regarded as an important marker for ovarian development, VTG-mRNA appeared to be increased through RNAi-induced gene silencing. In conclusion, CHH2 might negatively regulate ovarian development, and this study would provide new insights for further exploring the mechanism of crustacean ovarian development. Figures and Tables | References | Related Articles | Metrics

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Evaluation of thymol activity against pseudorabies virus in vitro and its action mode SONG Tianhao, PANG Lianfeng, CHEN Lingshuang, DENG Huidan, XU Zhiwen, ZHU Ling, REN Zhihua, DENG Junliang 2023, 35(1):  41-49.  DOI: 10.3969/j.issn.1004-1524.2023.01.05 Abstract ( 200 )   HTML ( 8 )   PDF (1848KB) ( 519 )   In this experiment, BHK-21 cells were used as the research model to explore the anti pseudorabies virus (PRV) activity and action mode of thymol at different mass concentrations in vitro. The maximum no-cytotoxic concentration (MNTC) of thymol on BHK-21 cells was detected by CCK-8 method, and the half maximal inhibitory concentration (IC50) was calculated to be (212.789±1.652) μg·mL-1. The half effective concentration (EC50) of thymol against PRV was determined as (30.710±0.303) μg·mL-1 and the therapeutic index (TI) of thymol was 6.929, which indicated that thymol was a high-efficiency and low-toxicity anti PRV drug. The effects of thymol on virus titer and one-step growth curve of PRV were detected by CPE observation method. The results showed that thymol could significantly reduce the virus titer of PRV and the virulence of PRV after proliferation in BHK-21 cells in a dose-dependent manner. The quantitative PCR was used to detect the gene copies of PRV gE in BHK-21 cells after different treatments to study the action mode of anti PRV effect of thymol in vitro. It was shown that the thymol exerted its antiviral activity mainly by inhibiting the proliferation of PRV in BHK-21 cells, as well as it could directly kill some PRV virus particles. Figures and Tables | References | Related Articles | Metrics

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Study on antibacterial and quorum quenching activity of a Pseudoalteromonas sp. DL3 ZHAO Saisai, ZHANG Haojie, CAI Xiulei, WANG Lirong, SHEN Xiaoran, CAO Zhi, SHAN Hu 2023, 35(1):  50-57.  DOI: 10.3969/j.issn.1004-1524.2023.01.06 Abstract ( 383 )   HTML ( 5 )   PDF (1746KB) ( 430 )   In this study, a strain DL3 was isolated from the microbial mucous membrane of antifouling attached steel sheet in aquaculture ponds. In order to clarify the activity of this strain and its potential application as beneficial bacteria, it was preliminarily identified by bacterial isolation culture, 16S rRNA sequencing and phylogenetic analysis. Oxford cup method and plate method were used to determine the bacteriostatic activity and quorum quenching activity. Based on phylogenetic analysis of the 16S rRNA gene sequence of strain DL3, this strain had the highest similarity with Pseudoalteromonas peptidolytica NBRC 101021T, with the closest affinity of 99.64%. The bacteriostasis test showed that the strain could significantly inhibit the growth of V. anguillarum and Pseudomonas aeruginosa, and showed that could inhibit the growth of Staphylococcus aureus, Escherichi coli, Salmonella, Streptococcus, Shigella, V. fluvialis, V. orientalis, V. harveyi and Bacillus pumilus to different degrees, and the antibacterial activity was strongest when cultured till 72 h. From the results of plate test, the strain DL3 had quorum quenching activity and could quench signal molecules such as 3-OXO-C6-HSL, C10-HSL, C12-HSL and 3-OXO-C14-HSL. In this study, the strain DL3 was successfully isolated and its antagonistic activity against pathogenic bacteria was clarified, which laid a foundation for further studies on the antibacterial mechanism of strain DL3 and its active products and the application of marine microorganisms in the prevention and control of animal bacterial diseases. Figures and Tables | References | Related Articles | Metrics

Horticultural Science

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Effects of exogenous melatonin on active components content and antioxidase activity of Anoectochilus roxburghii HE Xiuli, WANG Renmin 2023, 35(1):  58-66.  DOI: 10.3969/j.issn.1004-1524.2023.01.07 Abstract ( 464 )   HTML ( 19 )   PDF (1373KB) ( 507 )   Anoectochilus roxburghii (Wall.) Lindl. is a rare perennial monocot herb in the family Orchidaceae, of important medicinal value. Melatonin (MT) is a class of amine hormones with various physiological functions such as regulating body day and night and antioxidant. In order to investigate the role of melatonin in the process of tissue culture seedling transplanting to the substrate, melatonin with 5 μmol·L-1, 500 μmol·L-1 and 5 mmol·L-1 was used to study the effects of root irrigation on seedling growth and effective component content. The results showed that 5 μmol·L-1 melatonin root irrigation treatment could significantly increase the total flavonoid by 27.27% and total amino acids content by 21.79%, whereas 500 μmol·L-1 and 5 mmol·L-1 melatonin significantly increased the polysaccharide content by 20.79% and 23.88%. Under the three concentrations of melatonin, the total chlorophyll content was 41.56%-55.84% significantly higher than that of the control. Under 5 μmol·L-1 melatonin treatment, the activities of SOD, POD and CAT in leaves were significantly increased by 23.72%, 180.00% and 33.65%. In conclusion, melatonin could enhance the stress resistance of A.roxburghii by affecting chlorophyll content, metabolite accumulation and antioxidant enzyme activity, thus enhancing the vitality of A.roxburghii after transplanting. Figures and Tables | References | Related Articles | Metrics

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Transcriptome analysis of leaves of wild Portulaca oleracea L. based on Iso-Seq technology YE Meirong, HUANG Shoucheng, WANG Xiaopeng, LIU Airong, CUI Feng, KANG Jian 2023, 35(1):  67-78.  DOI: 10.3969/j.issn.1004-1524.2023.01.08 Abstract ( 431 )   HTML ( 16 )   PDF (3616KB) ( 565 )   The transcriptome of wild Portulaca oleracea’s leaves (leaves of three treatments: control, drought stress and low temperature stress) was sequenced and analyzed by Iso-Seq technology. The results showed that 641 732 polymerase reads were generated from the transcriptome of P. oleracea’s leaves. 26 758 071 subreads and 44 Gb total bases were obtained by quality control methods. 442 760 consensus sequences were generated by using CCS software. 391 258 full-length reads and 301 412 full-length non-chimeric reads were generated based on Smrtlink software. 103 298 transcripts were obtained from these consensus sequences by removing redundancy, and 39 717 unigenes were generated from these transcripts by removing redundancy. 40 952 LncRNAs and 38 419 CDS sequences were predicted from the unigenes. Unigenes were aligned to the sequences of public databases, including UniProt, Pfam, GO, KEGG, eggNOG, pathway and NR databases, in which 36 381 unigenes were annotated, and 25 898 (simple sequence repeats) SSR loci were detected in the unigenes. The differentially expressed genes (DEGs) among different treatment groups were screened by using DESeq 2.16 194(Up: 2 874, Down: 13 320), 16 093 (Up: 6 365, Down: 9 728) and 25 498 (Up: 15 163, Down: 10 335) DEGs were obtained in C vs DS, C vs LTS, and DS vs LTS, respectively. This study could provide reference for gene research and SSR development of P. oleracea. Figures and Tables | References | Related Articles | Metrics

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Screening of upstream regulators of AbF3'5'H gene in Ananas comosus var. bracteatus LIN Dongpu, ZANG Yaoqiang, ZHANG Xiaopeng, ZHOU Xuzixin, MA Jun 2023, 35(1):  79-89.  DOI: 10.3969/j.issn.1004-1524.2023.01.09 Abstract ( 320 )   HTML ( 9 )   PDF (5379KB) ( 473 )   Color is one of the most important traits of ornamental plants and also an important direction of ornamental horticulture breeding. To investigate the presentation mechanism of red-blue color of Ananas comosus var. bracteatus, the primary analysis of the kinds and concentration of anthocyanins in different tissues had been made, the promoter of AbF3'5'H was used to build the bait vector, and the yeast one-hybrid (Y1H) library was used to select the transcription factors that control the gene’s upstream activity; The yeast one-hybrid technique was used to verify the interaction between the selected transcription factors and the AbF3'5'H promoter. The results showed that the phenotypic color of the tissues were determined by the kinds and relative proportion of anthocyanins. AbF3'5'H was a key gene functioned in the species branch determination of the anthocyanin synthesis pathway, and was crucial for regulating the kinds and relative proportion of anthocyanins; AbBTB/POZ, AbHSP81-1 and AbGLOX-like could bind to the promoter of AbF3'5'H to regulate its transcription, suggesting that they might play important role in the regulation of anthocyanin anabolism in A. comosus var. bracteatus. These results had important theoretical and practical significance in understanding the regulation mechanism of anthocyanin biosynthesis, investigating the color formation mechanism and cultivating new leaf color variants of A. comosus var. bracteatus. Figures and Tables | References | Related Articles | Metrics

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Molecular mechanisms of chlorophyll-reduced cotyledon based on transcriptome sequencing in pumpkin XIONG Xingwei, WANG Yiqin, TIAN Huaizhi, ZHANG Suqin, GENG Guangdong 2023, 35(1):  90-102.  DOI: 10.3969/j.issn.1004-1524.2023.01.10 Abstract ( 396 )   HTML ( 64 )   PDF (3257KB) ( 655 )   In order to explore the mechanisms of chlorophyll-reduced mutation and excavate its key genes, pumpkin natural chlorophyll-reduced seedling was used as test material, and the transcriptome of the cotyledon was analyzed by high-throughput RNA sequencing (RNA-seq). The results showed that 12 687 differentially expressed genes (DEGs) were identified from 26 445 expressed genes, including 6 444 up-regulated genes and 6 243 down-regulated genes. Among them, 2 321 DEGs were transcription factor genes. Fourteen DEGs closely related to photosynthetic pigments were selected for qRT-PCR analysis. It was found that their expression level was consistent with the transcriptome data. KEGG enrichment analysis showed that the expression levels of biosynthesis of porphyrin and chlorophyll (Chl), photosystem Ⅰ, photosystem Ⅱ, photosynthesis antenna protein, electron transport, and F-type ATPase related genes were significantly down-regulated. Abnormal expression of glutamyl tRNA reductase, magnesium chelatase, and chlorophyll a oxygenase, and up-regulated expression of heme-related genes inhibited Chl synthesis. β-carotenoid 3-hydroxylase promoted carotenoid synthesis. In addition, feedback of photosynthesis inhibition also reduced Chl synthesis. The inhibition of Chl synthesis and the promotion of carotenoid synthesis led to pumpkin leaf etiolation. It laid a new foundation for the molecular analysis of pumpkin mutation and gene function. Figures and Tables | References | Related Articles | Metrics

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Evaluation of salt-alkali tolerance of different lotus varieties and screening of identification indexes LIU Yiping, ZHANG Yiqi, SU Shaowen, LIU Hongli, HE Dan, KONG Dezheng 2023, 35(1):  103-111.  DOI: 10.3969/j.issn.1004-1524.2023.01.11 Abstract ( 1307 )   HTML ( 49 )   PDF (825KB) ( 599 )   In order to study the tolerance of different lotus varieties to saline-alkali stress and to screen resistant varieties, using pot culture method, 20 lotus varieties were used as experimental materials, and 100 mmol·L-1 (NaCl∶NaHCO3=2∶1) hybrid saline-alkali stress treatment, 7 d after measuring the plant height, leaf area, photosynthetic pigments, chlorophyll fluorescence parameters, content of malondialdehyde, activity of antioxidant enzyme and content of osmotic regulatory substances, the saline-alkali tolerance of 20 lotus species was evaluated comprehensively by means of saline-alkali tolerance coefficient, correlation analysis, principal component analysis, membership function method and cluster analysis. The results showed that there were significant differences in the variation coefficients of saline-alkali tolerance among different lotus varieties. Except superoxide dismutase activity and peroxidase activity, the saline-alkali coefficients of other single indexes were significantly or extremely significantly correlated. The 12 single indexes were converted into 5 comprehensive indexes by using principal component analysis. The contribution rates of each comprehensive index were 36.175%, 18.709%, 13.470%, 11.379%, 6.610%, and the cumulative contribution rate reached 86.344%. With saline resistance value (D value) based on clustering analysis, 20 lotus varieties could be divided into four categories, first, there was strong salt-tolerant type, a total of four lotus varieties, and the second category of salt-tolerant type, a total of five lotus varieties, and the third category was not salt-tolerant type, a total of eight lotus varieties, the fourth category for sensitive type, a total of three varieties of lotus. The optimal evaluation model of salinity and alkali tolerance of lotus was established by stepwise regression analysis, D=0.453+0.148X1+0.122X2-0.122X7-0.033X8+0.093X11+0.037X12(R2=0.992), and the estimation accuracy was above 95.45%. Plant height, leaf area, malondialdehyde, proline, soluble sugar and soluble protein were selected as evaluation indexes of the saline-alkali tolerance of lotus. The saline-alkali tolerance of lotus could be determined by measuring these 5 indexes under the same conditions. Figures and Tables | References | Related Articles | Metrics

Plant Protection

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Isolation and identification of pathogen causing anthracnose disease on a rare plant species Heptacodium miconioides subsp. jasminoides ZHU Yan, ZHOU Mengya, ZHU Yinuo, HE Haiye, BAO Honghua, ZHANG Huijuan, JIANG Ming 2023, 35(1):  112-120.  DOI: 10.3969/j.issn.1004-1524.2023.01.12 Abstract ( 375 )   HTML ( 26 )   PDF (4223KB) ( 442 )   Anthracnose is one of the most important diseases of Heptacodium miconioides subsp. jasminoides, which seriously affects plant growth and threatens the survival of this rare species. To clarify the causative pathogen, infected leaves of H. miconioides subsp. jasminoides were collected, and the pathogen was obtained by the tissue isolation method. After determining the pathogenicity of the isolated strains, both morphological and multi-gene approaches were applied to identify the causative pathogen. Three strains were isolated, and only one isolate namely QZH could cause anthracnose disease according to Koch’s Rule. The morphological characteristics were identical with those of Colletotrichum fructicola. The multi-gene analysis results indicated that QZH and C. fructicola shared the same clade, with high support rates. Based on the morphological characteristics and multi-gene identification results, it was confirmed that the pathogen causing anthracnose disease of H. miconioidessubsp. jasminoides was C. fructicola. These data provided a start point for both disease prevention and pathogenic mechanism studies in the future. Figures and Tables | References | Related Articles | Metrics

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Isolation and identification of petal blight disease of Camellia japonica PU Meiying, WU Ziqiang, ZHANG Shiwen, LI Yanjie, ZHU Youjiao, WU Kun, CHEN Longqing, WANG Chao 2023, 35(1):  121-127.  DOI: 10.3969/j.issn.1004-1524.2023.01.13 Abstract ( 484 )   HTML ( 6 )   PDF (3400KB) ( 540 )   The ornamental effect of Camellia japonica petal blight disease was very serious. In order to identify the pathogenic bacteria and biological characteristics of C. japonica petal blight disease and improve the quality and ornamental value of C. japonica, and provide the basis for prevention and control. The pathogen of petal blight disease of C. japonica from Kunming Botanical Garden in Kunming City was isolated by tissue separation method, and pathogenic bacteria were identified by pathogenicity assay, morphological and molecular biological identification. One strain was isolated from the C. japonica ‘Wucai’ diseased tissue, there was white hyphae on PDA medium and had black conidia in the later stage of culturing for 7 days. when it was connected back to the healthy petals, the disease of lacing petals after inoculation was more obvious, which could cause the flowers to become yellow and brown. When it was serious, it could make the petals dry rot or wet rot, and grew mycelium, which was consistent with the symptoms in the field and conformed to the pathogenicity determination of Koch’s rule. Based on the phylogenetic analysis of multiple primers (ITS, LSU, β-tubulin), Pestalotiopsis portugallica clustered in the same clade. It was confirmed that the pathogen of petal blight disease of C. japonica was P. portugallica. This was the first report that P. portugallica infected the flowers of C. japonica and caused petal blight disease. Figures and Tables | References | Related Articles | Metrics

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Oxidative stress response and biosorption capacity of Aspergillus flavus TL-F3 under nano silver particles stress JI Yangyang, ZHANG Peng, LIU Xiaoqiang, DONG Zhenru, ZHANG Wei, FAN Ting 2023, 35(1):  128-137.  DOI: 10.3969/j.issn.1004-1524.2023.01.14 Abstract ( 352 )   HTML ( 31 )   PDF (4115KB) ( 493 )   In order to study the changes of oxidative stress of Aspergillus flavus TL-F3 and its adsorption capacity of nano silver particles (AgNPs) under AgNPs stress, a sequential batch experiment was carried out. The effects of AgNPs on the growth, cell morphology, extracellular polymer (EPS) secretion, antioxidant enzymes and adsorption capacity of A. flavus TL-F3 were investigated. It was shown that AgNPs could inhibit the growth of A. flavus TL-F3, and the inhibitory effects were positively correlated with the concentration of AgNPs. Scanning electron microscope analysis showed that, the hyphae of A. flavus TL-F3 was incompletely and the surface was damaged under AgNPs stress. Compared with the control group (without AgNPs),when the AgNPs concentration was 80 mg·L-1, the EPS content of A. flavus TL-F3 rose to 237.55 mg·g-1, and malondialdehyde content, superoxide dismutase activity and reduced glutathione peptide content were significantly (P<0.05) increased, and Na+K+-ATP enzyme activity was significantly (P<0.05) decreased by 50.37%. A. flavus TL-F3 had a certain adsorption capacity for AgNPs, and when the concentration of AgNPs was 1, 30, 50, 80 mg·L-1, the adsorption rate for AgNPs could reach 68.54% and above. In conclusion, A. flavus TL-F3 could be used for removing Ag and AgNPs from contaminated water bodies. Figures and Tables | References | Related Articles | Metrics

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Effects of exogenous epigallocatechin gallate on resistance of melon seedlings to powdery mildew FANG Mingya, YU Hongwei, WU Yaxian, HAN Wenyan, LI Xin, LIU Haihe 2023, 35(1):  138-145.  DOI: 10.3969/j.issn.1004-1524.2023.01.15 Abstract ( 318 )   HTML ( 10 )   PDF (1505KB) ( 573 )   Powdery mildew is a common fungal disease in melon production, which seriously affects the yield and quality of melon fruit. Effects of exogenous epigallocatechin gallate (EGCG) on the resistance of melon to powdery mildew was explored in this study. The results of diaminobenzidine (DAB) staining and malondialdehyde (MDA) determination showed that exogenous spraying with EGCG could reduce the accumulation of reactive oxygen species caused by powdery mildew infection, accompanied with the content of MDA decreased significantly, and the degree of cell membrane lipid peroxidation was decreased. The analysis of antioxidant enzyme activities in melon leaves showed that the activities of catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD) and peroxidase (POD) were increased significantly after exogenous EGCG pretreatment. Antioxidant enzymes activity was also induced by powdery mildew invasion, but exogenous EGCG pretreatment will further promote the improvement of antioxidant enzymes. The expression of related genes was further analyzed by real-time quantitative PCR. The results showed that the antioxidant enzyme related genes CmCAT, CmAPX, CmSOD and CmPOD were also induced by exogenous EGCG. The above results revealed that exogenous spraying EGCG could reduce the reactive oxygen species burst induced by powdery mildew infection by regulating the antioxidant enzymes system to improve the resistance of melon to powdery mildew. Figures and Tables | References | Related Articles | Metrics

Environmental Science

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Characteristics of soil nutrients and enzyme activities in rhizosphere of tobacco affected by bacterial wilt in Guizhou Province, China YANG Shengzhu, LI Xiang, LI Chaowen, CHEN Hainian, LIU Li, LU Yingang, CAO Zhuoyang 2023, 35(1):  146-155.  DOI: 10.3969/j.issn.1004-1524.2023.01.16 Abstract ( 299 )   HTML ( 5 )   PDF (3122KB) ( 540 )   To explore the occurrence regularity of tobacco bacterial wilt and provide theoretical basis for disease prevention in the respect of soil fertility and enzyme activity, the difference of rhizosphere nutrients and enzyme activities between healthy tobacco and diseased tobacco which suffered from bacterial wilt in Guizhou Province and the effects of climate on this difference were studied with multi-site randomized complete block design in three climate zones named mountain-hill areas of southeastern Guizhou (mid-subtropical monsoon humid climate), the hilly basin of central Guizhou (northern subtropical monsoon humid climate) and the plateau mountainous area of northwestern Guizhou (subtropical monsoon humid climate). The results showed that compared with the healthy, rhizosphere soil pH, available phosphorus and urease activity of the diseased were significantly reduced by 4.66%, 25.98% and 21.92%, respectively; while organic matter, CEC, total nitrogen, alkali hydrolyzable nitrogen, total phosphorus, total potassium, available potassium and catalase activities were significantly higher, respectively, and the rising trend was more obvious in the humid subtropical monsoon climate at high altitude. Pearson correlation analysis revealed that the correlation between tested indexes of the healthy was more and stronger than the diseased. Factor analysis made the conclusion more clear that the lower the pH, urease and phosphatase activity and the higher CEC, total nitrogen, total phosphorus available potassium and catalase activities, tobacco might be more susceptible to bacterial wilt. The stepwise discriminant analysis indicated that the discrimination model whose discriminant accuracy was 100% was constructed by soil pH, CEC, total nitrogen, alkaline hydrolysis nitrogen and available potassium, which could predict the susceptibility of tobacco plants to bacterial wilt in unknown soil. In conclusion, tobacco rhizosphere soil CEC, total nitrogen, alkaline hydrolyzable nitrogen and available potassium were higher and soil pH was lower, which might be more susceptible to tobacco wilt disease. Regulation of rhizosphere nutrients balance will play an important role in improving soil suppressive ability to bacterial wilt and constructing disease-resistant soil. Figures and Tables | References | Related Articles | Metrics

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Effects of corncob biochar application on soil characteristics and pepper growth under continuous cropping WANG Weiwei, MEI Yi, WU Yongcheng, WAN Hongjian, CHEN Changjun, ZHENG Qingsong, ZHENG Jiaqiu 2023, 35(1):  156-163.  DOI: 10.3969/j.issn.1004-1524.2023.01.17 Abstract ( 418 )   HTML ( 11 )   PDF (674KB) ( 734 )   In order to investigate the effects of biochar application on soil physiochemical properties, soil microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) and and plant growth indexes, different rates (5, 10, 20, 30 t·hm-2) of corncob biochar were added to pepper continuous cropping soils in the present study. It was shown that application of appropriate rate of biochar significantly (P<0.05) increased the contents of soil organic carbon (SOC), total nitrogen, total phosphorus, available phosphorus and available potassium as compared with the CK treatment without biochar application, yet decreased the total potassium content in soil. The soil MBC/MBN and MBC/SOC were significantly (P<0.05) decreased with application of biochar as compared with CK. When the biochar addition rate was above or equal to 10 t·hm-2, the soil MBC and MBN contents were significantly (P<0.05) increased as compared with CK. When the biochar addition rate was 10-20 t·hm-2, the soil MBN/TN was significantly (P<0.05) increased as compared with CK. The correlationship analysis showed that the soil MBC and MBN were significantly (P<0.01) positively correlated with soil total nitrogen, organic carbon, total phosphorus and available phosphorus, and were significantly (P<0.01) negatively correlated with soil total potassium. When the application rate of biochar was 5-20 t·hm-2, the pepper yield per plant was significantly (P<0.05) increased as compared with CK, and the highest value was recorded under the application rate of 20 t·hm-2. But, the higher application rate did not support the further increase of pepper yield. In conclusion, the modest biochar application could improve soil micro-environment and soil fertility, promote pepper growth and increase pepper yield. Figures and Tables | References | Related Articles | Metrics

Food Science

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Comparison of fruit yield, disease resistance and storage ability of Lycium bararum sprayed with different plant immune inducers LI Yonghui, LI Jie, FENG Lidan, HE Jing, ZHANG Xu, LIU Xianglin 2023, 35(1):  164-174.  DOI: 10.3969/j.issn.1004-1524.2023.01.18 Abstract ( 463 )   HTML ( 14 )   PDF (1813KB) ( 587 )   In this study, six-year-old Ningqi Ⅶ wolfberry (Lycium bararum) plants under the normal management were used as test materials. Four plant immune inducers, i. e., acetylsalicylic acid (ASA), methyl jasmonate (MeJA), β-aminobutyric acid (BABA), amino oligosaccharide (AOS) were sprayed on the plant as treatments, and the fungicide and water were used as controls. The changes of fruit yield, weight loss rate, natural infection rate, active oxygen metabolism and phenylpropane metabolism of Ningqi Ⅶ were measured, to explore the effects of spraying different plant immune inducers on the fruit yield, disease resistance and storage ability of Ningqi Ⅶ. The results showed that spraying four kinds of plant immune inducers on the leaves before fruit harvest could induce varied disease resistance of Ningqi Ⅶ. Compared with the fungicide control and water control, 1 mg·mL-1 BABA exhibited the best immune induction effect. With induction by 1 mg·mL-1 BABA, the activities of superoxide dismutase (SOD), peroxidase (POD) and phenylalanineammonialyase (PAL) were significantly (P<0.05) increased on the 21st day, the accumulation of secondary metabolites (total phenols and flavonoids) were significantly promoted on the 28th day, and the fruit yield was significantly enhanced on the 14th, 21st, 28th day. Therefore, 1 mg·mL-1 BABA could be sprayed per 7 days and five times continuously from the young fruit stage of wolfberry, and the induction of 21 days could improve the disease resistance and effectively enhance the fruit storage capacity of Ningqi Ⅶ. Figures and Tables | References | Related Articles | Metrics

Quality and Safety of Agricultural Products

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Determination of 17 sulfonamides in infant formula by accelerated extraction and ultra-high performance liquid chromatography/mass spectrometry JI Xiaofeng, WANG Xiaoli, LYU Wentao, ZHOU Zhongjing, WU YUxiao, YANG Hua 2023, 35(1):  175-183.  DOI: 10.3969/j.issn.1004-1524.2023.01.19 Abstract ( 367 )   HTML ( 26 )   PDF (823KB) ( 404 )   A method for the determination of 17 sulfonamides residues in infant formula by accelerated solvent extraction (ASE) and ultra-high performance liquid chromatography/mass spectrometry (UHPLC-MS/MS) was developed. The linearity, sensitivity, recovery rate and matrix effect of the method were verified. Meanwhile, the screening analysis for 17 sulfonamides in infant formula collected from the market was carried out. The results showed that the linearity of sulfonamides were in the range of 0.5-100 μg·kg-1, and the correlation coefficient was greater than 0. 998, the recoveries were 75.3%-103.6%, the relative standard deviation was less than 11.0%, the matrix effect was 0.4-1.0, the detection limit for sulfonamides in infant formula was 0.1-3.0 μg·kg-1, and the limit of quantification (LOQ) was 0.3-10 μg·kg-1. The developed method has the merits for convenient extraction, high sensitivity and accuracy, and the method can simultaneously determine 17 sulfonamides residues in infant formula. Figures and Tables | References | Related Articles | Metrics

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Residue dynamics and dietary intake risk assessment of tolfenpyrad in broccolini WU Yao, ZHANG Gangming, ZHOU Chengyun, WU Yanjun, ZHANG Dan, DONG Daixing, HONG Wenying 2023, 35(1):  184-190.  DOI: 10.3969/j.issn.1004-1524.2023.01.20 Abstract ( 229 )   HTML ( 19 )   PDF (849KB) ( 444 )   The residue dissipation dynamics of tolfenpyrad in open field cultivation of broccolini was analyzed, and the dietary intake risk was assessed by field trial data. The results of residue tests showed that the half-life of tolfenpyrad in broccolini was 3.35 d when the 15% tolfenpyrad SC was applied once at double recommended dosages (225 g·hm-2). The residue risk in the harvested broccolini was positively correlated with application dose and spraying frequencies by final residue tests. The risk assessments showed that risk quotients (RQ) of tolfenpyrad were below 1 from 1 h to 17 d after one application of the pesticide at 225 g·hm-2 but there were big risks from 1d to 7 d after two or three applications. The dietary risk of tolfenpyrad in broccolini was accepted after 3 d by two applications at 112.5 g·hm-2. The safety interval was suggested to be 5 d in the open field if the recommended dosages (112.5 g·hm-2) was applied no more than 2 times. Figures and Tables | References | Related Articles | Metrics

Biosystems Engineering

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Numerical analysis of flow characteristics and structural optimization of bellows based on CFD-DEM ZHANG Yifan, HE Ruiyin, DUAN Qingfei, XU Yong 2023, 35(1):  191-201.  DOI: 10.3969/j.issn.1004-1524.2023.01.21 Abstract ( 272 )   HTML ( 4 )   PDF (4421KB) ( 510 )   In order to explore the relationship between bellows structural parameters and conveying uniformity, the optimal parameter combination was obtained to improve the uniformity of pneumatic fertilizer discharge. Based on CFD-DEM coupling simulation technology, this paper constructed a quadratic response surface model with the variation coefficient of fertilizer discharge uniformity as the response value. On the basis of single factor test, BDD method was used to study the influence of the interaction between bellows width, bellows spacing and wavelength on fertilizer discharge uniformity, and the best parameter combination of bellows was obtained, Finally, the bench test was carried out to verify the simulation model and optimization results. The simulation results showed that the variation coefficient of fertilizer discharge uniformity firstly decreased and then increased with the increase of wavelength, width and ripple spacing. The order of significance of the influence of bellows structural parameters on fertilizer discharge uniformity was width>wavelength>ripple spacing. The optimal structural parameters of bellows were wavelength 18.103 mm, ripple spacing 12.158 mm and width 8.863 mm. At this time, the variation coefficient of fertilizer discharge uniformity was 7.5%. In the single factor bench test, the change trend of urea particle simulation predicted value was consistent with the actual value of the bench, and the values basically coincided. The average value of the relative error between the variation coefficient of corrugated pipe fertilizer discharge uniformity of the optimal parameter combination and the predicted value of the simulation test was 5.84%, which showed that the simulation model was accurate and reliable. The change trend of compound fertilizer particles was basically consistent with that of urea particles, which showed that the simulation model was universal. This study can provide a reference for the use and optimization of bellows. Figures and Tables | References | Related Articles | Metrics

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Apple leaf image segmentation algorithm based on improved LinkNet ZHU Shisong, MA Wanli, ZHAO Lishan, ZHENG Yanmei, ZHENG Xianbo, LU Bibo 2023, 35(1):  202-214.  DOI: 10.3969/j.issn.1004-1524.2023.01.22 Abstract ( 227 )   HTML ( 38 )   PDF (5615KB) ( 604 )   The traditional methods of segmenting apple leaf images and measuring leaf geometric parameters are moderately accurate but inefficient. To address this problem, an apple leaf image segmentation algorithm based on a deep learning semantic segmentation model and transfer learning was proposed to accomplish efficient and accurate segmentation of apple leaves. The proposed method used LinkNet as the base structure, with the following improvements: ResNet18 was utilized as the backbone network of the encoder and incorporates transfer learning ideas to accelerate model fitting; The number of encoder and decoder blocks was reduced to decrease network complexity; The channel reduction scheme was modified to decrease the parameter quantity in up-sampling; The sub-pixel convolution was introduced to replace the final block to reduce computational costs. Combined with the focal loss, the effectiveness of the improved LinkNet was verified on the standard apple leaf dataset. The experimental results showed that the proposed method achieved a segmentation accuracy of 97.27% and an inference time of 7.82 ms, inference time was decreased by 39.89% compared to the original LinkNet with a slight difference in precision, and the parameter quantity and floating point of operations were significantly reduced. In addition, the inference speed of the improved LinkNet was much faster than that of popular methods such as FCN, U-Net and DeepLabV3+. Therefore, the proposed method could segment the leaf body quickly while better maintaining detailed features such as blade edge serrations. It enabled the efficient and accurate segmentation of apple leaves and provided a novel approach to thinking for fast measurement of leaf area and other geometric parameters. Figures and Tables | References | Related Articles | Metrics

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Pig posture detection based on improved YOLOv4 model LI Bin, LIU Dongyang, SHI Guolong, MU Jingsheng, XU Haoran, GU Lichuan, JIAO Jun 2023, 35(1):  215-225.  DOI: 10.3969/j.issn.1004-1524.2023.01.23 Abstract ( 397 )   HTML ( 172 )   PDF (5234KB) ( 594 )   In order to improve the speed and performance of pig posture detection in piggery environment, an improved Mini_YOLOv4 model was proposed in the present assay based on YOLOv4 model. Firstly, the feature extraction network of YOLOv4 was changed into lightweight MobileNetV3 network structure to reduce the amount of model parameters. Secondly, the deep separable convolution was used to replace the traditional convolution in the CBL_block1 and CBL_block2 modules of the detection network to avoid the memory shortage and high delay problems caused by the complex model. Finally, the 3×3 convolution at each scale of the original YOLOv4 network was changed into the Inception network structure to improve the accuracy of the model. The performance of the above models was evaluated in the detection of five types of postures of pigs, i.e. stand, sit, lie, ventral and lateral. It was shown that, compared with the YOLOv4 model, the detection accuracy of the proposed Mini_YOLOv4 model was improved by 4.01 percentage points, and its detection speed was almost doubled. In summary, the proposed model could improve the real-time performance and ensure the accuracy of pig posture detection, which could provide technical references for pig behavior identification. Figures and Tables | References | Related Articles | Metrics

Agricultural Economy and Development

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Study on grain and ecological effects of arable land use change in major grain-producing areas in China LUO Haiping, PAN Liuxin, HU Xueying, LIU Zuguang 2023, 35(1):  226-237.  DOI: 10.3969/j.issn.1004-1524.2023.01.24 Abstract ( 328 )   HTML ( 88 )   PDF (1541KB) ( 448 )   By integrated use of the transfer matrix of land use, land-use change atlas model, the dynamic correction methods of ecosystem services value model, the changes of grain output and ecosystem service value profit and loss caused by the change of arable land utilization in major grain-producing areas were measured from 2000 to 2018, and the main arable land use change types restricting the promotion of grain output and ecologial service abilities was figured out, and a targeted optimization path was proposed. The results showed that, the arable land area in major grain-producing areas showed the spatial differentiation of “north increased and south reduced” and the quantity change of “reduced more than increases”. The net transfer of arable land was 205.98×104 hm2, and construction land was the main type of arable land transfer. The output effects of arable land use change could be divided into four types, namely, ecological appreciation-grain yield increase type (type Ⅰ), ecological impairment-grain yield reduction type (type Ⅱ), ecological appreciation-grain yield reduction type (type Ⅲ) and ecological impairment-grain yield increase type (type Ⅳ). The area proportion of type Ⅰ-Ⅳ in major grain-producing areas was 18.30%, 13.36%, 33.19% and 35.05%, respectively, at the provincial level and resulted in a total of 4.171×1010 yuan of ecosystem service value loss and 9.253×106 t of grain production. The arable land occupied by construction land and the arable land supplemented by unused land were the most harmful and most beneficial types of arable land use change, respectively. Therefore, it was suggested to strictly control the “non-agricultural” and “non-grain” of arable land, strengthen the ecological improvement of unused land, and actively develop complex economic agriculture such as under-forest economy and grassland economy. Figures and Tables | References | Related Articles | Metrics

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Impact of “26 counties” policy based on concept of green development on urban-rural income gap in Zhejiang Province, China LI Baozhi, ZHUO Ni, HUANG Hexiao, ZHU Qibiao 2023, 35(1):  238-248.  DOI: 10.3969/j.issn.1004-1524.2023.01.25 Abstract ( 467 )   HTML ( 1207959553 )   PDF (1329KB) ( 493 )   In order to explore the new driving forces and new paths to narrow the urban-rural income gap, the case of “26 counties” policy based on the ideas of green development in Zhejiang Province, China, was focused and analyzed in the present assay. The realistic background of the “26 counties” policy was introduced, the main contents of the “26 counties” policy were summarized, and the mechanism of the “26 counties” policy affecting the urban-rural income gap was expounded. By using the panel data of 83 county-level administrative regions in Zhejiang Province from 2013 to 2019, the impact of the “26 counties” policy on the urban-rural income gap was examined through the difference-in-difference model. The results showed that the “26 counties” policy significantly reduced the urban-rural income gap. To be more specific, the “26 county” policy could significantly narrow the urban-rural gap of net operation income and net transferred income, but the effect on narrowing the urban-rural gap of wage income and net property income was not significant. These findings not only provided practical basis for the green development towards common prosperity, but also provided useful references for policy-formulation to stimulate the advantages of rural ecological elements. Figures and Tables | References | Related Articles | Metrics