Loading...

Table of Content

    15 September 2024, Volume 26 Issue 9
    AGRICULTURAL INNOVATION FORUM
    Spatial-temporal Pattern and Distribution Evolution of Grain Production in China
    Haoyu DENG, Chengmin LI, Jian CAO, Yulan SONG, Jian LIU
    2024, 26(9):  1-11.  DOI: 10.13304/j.nykjdb.2023.0142
    Asbtract ( )   HTML ( )   PDF (3737KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Comprehensive examination of the differences in food production and the spatio-temporal evolution characteristics from the county scale is an important reference value for improving China?’?s grain production and guaranteeing food security issues. The spatio-temporal pattern and distributional dynamic evolution of China?’?s grain production were investigated based on data from 2 545 county scales from 2000 to 2020, using standard deviation ellipse, three-stage nested Theil index and stochastic Kernel density estimation etc methods. The results showed that, the overall level of China’?s grain production rose at a slow pace, the growth rate of food production showed an obvious fluctuating trend from 2000 to 2020, and China’?s grain production would remain stable but the growth rate of fgrain production would decline slightly over a long period of time in the future. In terms of spatial distribution pattern, the center of grain production in China was moving to the northwest, showing the directionality of northeast-southwest, and the development dispersion of southeast-northwest. In terms of spatial difference, the overall difference in China’?s grain production was showing an increasingly high level, and although the contribution rate of county difference in China’?s grain production had decreased from 49.94% to 29.51%, the county scale was still the most important source of the overall difference. Therefore, spatial differences were mainly dominated by county differences, followed by inter-provincial differences, inter-municipal differences and inter-regional differences, respectively. In terms of spatial effect, China?’?s grain production level showed a growing trend and the possibility of local convergence, and its spatial effect had continuity and had obvious positive correlation spatial effect under different time and county space. In coordination with the development trend and practical needs of China’?s regional economic structure transformation, the “double cycle” development pattern captured the differences in regional grain production resilience in detail, which was conducive to the formulation of reasonable and effective grain production policies tailored to the local conditions of each region, and was of great significance for steadily breaking through the grain production dilemma and coordinating grain production security.

    BIOTECHNOLOGY & LIFE SCIENCE
    Discovering of QTLs and Candidate Genes Related to Rice Heading Period Traits Based on BSA-seq
    Ronghua WEI, Ming YIN, Wensheng WANG, Yanru CUI
    2024, 26(9):  12-24.  DOI: 10.13304/j.nykjdb.2024.0216
    Asbtract ( )   HTML ( )   PDF (6935KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    As one of the important traits of rice, rice heading date is closely related not only to the rice growth period but also to rice yield, quality and stress resistance, which determines the planting area and seasonal adaptability of rice varieties. Therefore, the location of rice heading date related genes plays an important role in rice production. In this study, HQ20, Jin 23B and their F4 population constructed were used as the materials. According to the heading stage of the rice in the population, it was divided into 3 levels including early, middle and green plant (not heading), and 3 mixed pools of early, middle and green were constructed. The bulked-segregant analysis sequencing (BSA-seq) method was used to discover rice heading period genes. The results showed that the comparison rate between BSA-seq results and the reference genome was over 94%, and the 4× genome coverage rate was over 80%. Based on this, when the confidence level was 0.95, by SNP-index algorithm 17 SNPs located on 4 chromosomes (6, 7, 8 and 9) were obtained which had consistent association intervals with indel. Further analysis of candidate genes in the region found that 61 genes had non-synonymous mutations. GO and KEGG enrichment analysis showed that pathways closely related to rice heading stage included UDP-glycosyltransferase activity, positive regulation of cell cycle G2/M phase transition, and phytohormone signal transduction. Finally, combining haplotype analysis in the 3K rice database and published expression data, 3 key candidate genes for heading stage were discovered including LOC_Os07g22720LOC_Os07g23740 and LOC_Os08g07200. The above results laid the foundation for genetic improvement of rice heading period traits and analysis of genetic basis.

    Dynamic Change of Important Traits During the Development of Flax Seed
    Li ZHAO, Jingjing HOU, Bin WANG, Minglu YUAN, Jie LIU
    2024, 26(9):  25-33.  DOI: 10.13304/j.nykjdb.2023.0821
    Asbtract ( )   HTML ( )   PDF (2960KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    In order to determine the accumulation dynamics of flax seed quality and the best harvest time, optimize the quality breeding and high quality cultivation technology of flax, 5 germplasms including 1158-S, BISOW, Longya 10, CHLH-99 and 38078, were used to analyze the dynamic change of water content,1 000-seed weight, oil content, 5 major fatty acids and the lignan content. The samples were taken at 5 d after flowering and sampled every 5 d until maturity. After sampling, the seeds were immediately peeled the capsule to determine fresh weight, dry weight, oil content, 5 kinds of main fatty acids content and lignan content. The results showed that the water content, palmitic acid and linoleic acid of different varieties decreased gradually, and reached stability at 40 (water content), 30 (palmitic acid) and 25 d (linoleic acid) after flowering; while the 1 000-seed weight, oil content, α-linolenic acid content and lignan content increased gradually with the ripening of seeds, and reached stabilization at 40, 35, 35 and 40 d after flowering in sequence. The content of stearic acid decreased first and then increased to stable; oleic acid rose first, then decreased and then increased rapidly to stable.These showed that the palmitic acid and linoleic acid accumulated at the beginning of seed stage, stearic acid and oleic acid accumulated was mainly in the middle and late stages of seed development,whereas the accumulation of seed weight, oil content, α-linolenic acid and lignan content occurred during the whole seed development period. The most positive effect of the accumulation of each index was between dry weight and oleic acid content, and the most negative effect was between oil content and palmitic acid content. In order to increase the content of oil, α-linolenic acid and lignan in flaxseed, it is necessary to prolong the synthesis time of oil, ɑ-linolenic acid and lignan in the plant body as much as possible or increase their growth rate in the early stage. 40 d after flowering can be regarded as the best harvest period of the flax important quality accumulation.

    Study on the Flowering Biology and Pollination Characteristics of Goji Berries
    Yunxing WAN, Ziyang YAN, Jun YAO, Liming GUO, Jinzhong ZHU, Jianning TANG, Caiyun QIAO, Haiou KUANG, Xueyang GONG, Dan YUE, Wenzheng ZHAO
    2024, 26(9):  34-43.  DOI: 10.13304/j.nykjdb.2024.0198
    Asbtract ( )   HTML ( )   PDF (2731KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Insufficient pollination is one of the direct causes of flower and fruit drop in goji berries. Aiming to determine the flowering characteristics, ‘Ningqi 10’ was taking as material to analyze flowering period, including flower color, stigma receptivity, pollen vitality, and nectar secretion at different stages. The study also analyzed the pollination characteristics of common pollinating insects, such as the duration of a single visit to flowers and the number of pollen deposition on the stigma. The results showed that during 12~24 h after flowering and the petal color changed to light purple and white purple, the stigma receptivity, pollen vitality, and nectar secretion were the highest, with significant differences (P<0.05) compared to other stages. The number of pollen deposition on the stigma of common pollinating insects after a single visit (moths>bees>non cushioned bees) showed significant differences compared to natural pollination. The average duration of bees visiting purple flowers was 4.1 s, and the difference was extremely significant (P<0.01) compared to the duration of bees visiting yellow flowers (average 1.7 s). The number of pollen deposition on the stigma of common pollinating insects after a single visit to flowers (moths>bees>non cushioned bees) showed significant differences compared to natural pollination. However, in terms of overall efficiency and the number of pollinating insect visits, it was recommended to introduce pollinating insects (such as bees) to enhance the assisted pollination of goji berries and improve the fruit setting and seed setting of ‘Ningqi 10’. The research results provided scientific basis for the development of assisted pollination measures for goji berries.

    Bioinformatics Analysis of Porcine CREBRF Gene and Its Expression Pattern
    Xiaorong GUO, Ying LIU, Jiazhen FAN, Tao HUANG, Rong ZHOU
    2024, 26(9):  44-53.  DOI: 10.13304/j.nykjdb.2024.0154
    Asbtract ( )   HTML ( )   PDF (4501KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    CREBRF gene plays an important regulatory role in the reproductive process of female animals. In order to deeply understand the characteristics and functions of CREBRF gene in pigs, bioinformatic analysis of the CREBRF gene was performed, and the expression pattern of CREBRF in ovarian tissues at different stages of Bama pigs was analyzed by RT-qPCR. The results showed that 20 mutations of CREBRF gene were identified in the genomes of 5 pig breeds, 7 of which were synonymous mutations and 13 were missense mutations. The CDS region of the porcine CREBRF gene was 1 920 bp in length, encoding a total of 639 amino acids, with a high instability coefficient, a hydrophilic protein, 85 high-confidence phosphorylation sites and 4 glycosylation sites, and the mRNA of CREBRF had 20 high-confidence m6A methylation modification sites. CREBRF proteins were more conserved in pig, human and mouse, and the secondary structures of pig and human CREBRF proteins were more similar. RT-qPCR results showed that the expression of the CREBRF gene in pig ovaries was higher at 0 and 28 d after birth, and with the growth and development of pigs, the expression decreased significantly at 180 d after birth, and the expression of CREBRF increased again at 38 and 80 d after gestation in sows. By comparing the base mutations in the CDS region of CREBRF gene in different breeds of pigs and analysing the physicochemical properties and expression pattern of the gene, CREBRF gene was highly expressed in the ovarian tissues of pigs at the fetal stage, early birth and gestation, and it was speculated that CREBRF plays an important role in the reproductive process of sows, which provided a reference for the mining of genes for high porcine fertility and the development of molecular markers.

    Study on Folding of SprD Protein Mediated by Pro-peptide in vitro
    Dan LI
    2024, 26(9):  54-61.  DOI: 10.13304/j.nykjdb.2023.0176
    Asbtract ( )   HTML ( )   PDF (3215KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    To improve the folding and maturation efficiency of proteins that were first synthesized as precursors, the bacterial-derived SprD subtilisin was used as the research object and the folding and maturation of precursors were compared comprehensively by taking recombination expression of proteins, site-directed mutation of amino acids, purification of inclusion bodies, refolding of proteins in vitro anddetermination of enzyme catalytic abilities many other measures. The resluts showed that SprD precursors took about 230 min to complete the maturation under the mediation of wild-type pro-peptides. Mutations of E112A, S221A and S221C in sequences of mature peptide led to the prolongation or the failure of maturation. The tandem expression of pro-peptide and deletion of tyrosine at cleavage site between pro-peptide and mature peptide shortened the maturation time to 80~160 min and increased the maturation efficiency by 0.5~2.0 times, and the catalytic abilities of the corresponding mature enzymes were not affected. Although the single-site mutations in pro-peptide had little effects on maturation, they contributed the improvement of catalytic ability. Therefore, the maturation of proteins mediated by pro-peptides and the alternation of enzyme catalytic ability were 2 relatively independent processes and the expression modes of pro-peptide and the changes of cleavage site were suitable ways to promote protein maturation in vitro. Above results would provide a reference method for accelerating protein maturation and protein modification.

    INTELLIGENT AGRICULTURE & AGRICULTURAL MACHINERY
    Construction of A Standardized Height-diameter Equation for the Main Tree Species in China Suitable for the GlobalAllomeTree International Data Platform
    Fei YANG, Zhongke FENG, Yangyang ZHOU, Wensheng CHENG, Zhichao WANG
    2024, 26(9):  62-71.  DOI: 10.13304/j.nykjdb.2023.0116
    Asbtract ( )   HTML ( )   PDF (557KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    GlobalAllomeTree is an international network platform that shares differential equations, which has gradually received high global attention. Currently, aiming at the lack of growth differential equations for major tree species in China on this platform, this study updated the standardized tree height-diameter relationship equation for major tree species in China. Due to the canopy and lower shrubs and grass cover, the measurement of tree height relative to diameter at breast height (DBH) is difficult, so mathematical tools need to be used for regression calculations. 36 tree species were selected as materials to construct a tree height-diameter relationship equation. Based on the binary volume model of major tree species in China and the one-dimensional volume table of each region, 1 692 sets of tree height-diameter data generated with a sampling diameter order of 1 cm interval were used as equation samples, and 1 238 sets of field survey data were used as validation samples. The modeling results showed as followed: the correlation coefficient (R2) of the national universal tree height-diameter equation fitting based on 1 692 sets of tree height diameter data from 36 main tree species was 0.801, indicating that the equation fitting results were good, so the tree height can be estimated by measuring the diameter at breast height (H,m) - diameter at breast height (D,cm) square H=aDb; using the equation to fit 36 main tree species, the results showed that the determination coefficients (R2) of the tree height-diameter at breast height equation for 36 main tree species were all greater than 0.916, and the values of mean error (ME), mean absolute error (MAE), and root mean square error (RMES) were relatively small. The overall accuracy of the equation was high, which could be widely promoted; using 1 238 analytical tree data collected from field work, the accuracy of the equation was verified based on the fitting formulas and parameter estimates a and b of the tree height diameter equation for 36 main tree species. The results showed that the average relative error of the equation prediction was 16.86%, within the allowable range of error, and the model format was standardized. Above results provided scientific reference for users of the GlobalAllomeTree platform.

    Design of a Harvesting Machine for Panax notoginseng Stems and Leaves Under the Forest and Simulation Experiment of a Reciprocating Cutting Blade
    Jiaxin ZHENG, Shishun WANG, Fan TANG, Longtu ZHU, Ji LUO, Wenchai YANG
    2024, 26(9):  72-82.  DOI: 10.13304/j.nykjdb.2024.0176
    Asbtract ( )   HTML ( )   PDF (2020KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Panax notoginseng belongs to the long stemmed crop, and the harvesting of its stems and leaves is one of the important processes. Aming at the problems of high labor intensity and lack of mature harvesting equipment, based on the agronomic requirements of Panax notoginseng cultivation and the mechanical parameters of Panax notoginseng stems, a harvesting device for Panax notoginseng stems and leaves under the forest was designed, which mainly consisted of a control box, a frame, and a leaf cutting device. The overall size, cutting stroke, forward speed and cutting pair width of the device were determined, and the device structure was compacted, which met the requirement of harvesting. The design of key structural parameters for reciprocating cutters mainly included moving blade, fixed blade, crank connecting rod mechanism, blade protector, etc. The reciprocating cutter could meet the technical requirements while didn’t damage seedlings and miss cutting Panax notoginseng stems and leaves. A kinematic analysis was conducted on the cutter, and it was determined that the cutting speed was 0.4~0.8 m?s?1, which ensured the cutting effect while also ensuring the stability and safety of the entire machine. A rigid flexible coupling simulation model of Panax notoginseng stem and cutting blade was constructed, and cutting blade simulation analysis was carried out with the maximum cutting force as evaluation index. Based on three factors and three levels test results, it was found that the factors affecting cutting from large to small were cutting angle, cutting speed and tool configuration. The reduction effect of blade shape on Panax notoginseng stem cutting force was determined, with triangular blade>trapezoidal blade>rectangular blade, The optimal parameter combination for the stem cutting blade of Panax notoginseng was cutting angle of 90.5°?, triangular blade shape, and cutting speed of 0.52 m·s?1. At this condition, the maximum cutting force was 7.46 N, which met cutting requirements.

    Research on Diagnostic Method of Citrus Anthracnose Based on Image ROI Fusion Feature
    Xiaofei XIONG, Xiuqin WANG, Cuizhen ZHUANG, Jiaxian GUO, Xinrui XIE, Jianwei WU, Qifeng LI
    2024, 26(9):  83-92.  DOI: 10.13304/j.nykjdb.2024.0120
    Asbtract ( )   HTML ( )   PDF (4920KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Anthracnose is a pervasive and serious disease in citrus orchards. In order to improve the accuracy and efficiency of disease identification under orchard environmental conditions and ensure fruit yield and quality, this study recognized the ROI fusion features of diseases image in orchard. A dataset comprising of 9 types of citrus anthrax images depicting various disease sites and stages was collected for model training purposes. In the disease ROI feature extraction and detection module, image color, texture features, and their fused features were extracted to obtain more disease feature information, and form an SVM classifier. The trained SVM classifier was used to detect and identify the disease images to be tested. The trained SVM classifier successfully detected and recognized the target disease images by fusing spectral and texture features, the average accuracy rate of disease identification can reach 94%, with an average processing time for disease identification of 0.005 s. This method had high accuracy and strong robustness for the detection and recognition of citrus anthracnose in complex natural environments, and was of great significance for the prevention and control of citrus diseases.

    Design and Experiment of a Banana Straw Crushing and Returning Machine with Rotting Agent Spraying Device
    Yang GAO, Yue LI, Shiquan WEI, Chun HUANG, Zihan WU, Chenhui WEI, Qirun HUANG
    2024, 26(9):  93-104.  DOI: 10.13304/j.nykjdb.2024.0150
    Asbtract ( )   HTML ( )   PDF (2341KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Aiming at the current problems of poor crushing effect, high energy consumption, slow decomposition speed and low degree of decomposition of banana straw after crushing etc., a banana straw crushing and returning machine with rotting agent spraying device was designed. The straight shaped knife was optimized, the arrangement of knife roller was symmetrical single helix arrangement, the crushing knife axle rotational speed range was 1 500~1 860 r·min-1, the spraying device selected 180 L tank and fan nozzle with spray angle of 90°, single nozzle flow rate was 0.8 L·min-1, and 4 nozzles were fixed to the drug pole at 370 mm intervals. A two-factor, three-level field test and a comparative test was conducted with the forward speed of the machine and the rotational speed of the knife roller as independent variables, and the qualified rate of straw crushing and unevenness of spreading as dependent variables. The results showed that the machine forward speed was 1.4 m·s-1 and the knife roller rotational speed was 1 860 r·min-1, and the qualified rate of banana straw crushing was 93.08% and the unevenness of spreading was 12.11%. This device realized the joint operation of banana straw crushing and rotting, which not only improved the crushing effect of straw but also promoted the decomposition of straw organic matter compared with the previous generation of machines, and provided technical references for the research of the subsequent banana straw rotting and field returning machine.

    Research on Grapevine Structure Segmentation Method Based on Machine Vision
    Guoyu HU, Yalan DONG, Gulbahar Tohti, Guang LIU, Jianping ZHOU
    2024, 26(9):  105-111.  DOI: 10.13304/j.nykjdb.2023.0094
    Asbtract ( )   HTML ( )   PDF (3712KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    The precisive segmentation of grapevine structure is an important prerequisite for reasoning and locating the pruning points. To precisely segmentate grapevine structure, this article established a vine structure data set under natural planting conditions, and proposed a grape vine structure division method based on the U-net model. Through the comparative experiment of backbone feature extraction network and model segmentation performance, the optimal U-net model structure was obtained and its segmentation performance under different density degree targets was verified. The results showed that the precision of the U-net model with VGG 16 as the backbone feature extraction network was 93.55%, the recall was 94.15%, the mean pixel accuracy was 94.15%, and the mean intersection over union was 88.65%. Compared with traditional image segmation methods and control group model segmentation effects, it could ensure that the structure of the grape vines was complete in the context of natural planting, and the connection relationship between the structure was correct, so it was suitable for the segmentation task of grapevine structures with shade between plants, laid the foundation for achieving intelligent grape vines in winter pruning operations.

    ANIMAL AND PLANT HEALTH
    Preliminary Function Analysis of GhERF020 Gene in Response to Verticillium Wilt in Cotton
    Huiting WENG, Haiyang LIU, Huiming GUO, Hongmei CHENG, Jun LI, Chao ZHANG, Xiaofeng SU
    2024, 26(9):  112-121.  DOI: 10.13304/j.nykjdb.2023.0407
    Asbtract ( )   HTML ( )   PDF (3709KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Verticillium wilt (VW) is a disruptive symptom caused by Verticillium dahliae, which affects fiber yield and quality of cotton in China. AP2/ERF transcription factors play prominent role in plant growth, development and stress response. In order to excavate the genes related to resistance to VW in cotton and explore their biological functions, the candidate gene GhERF020 (XM_016842745.1) was obtained by homologous alignment of AT1G22810.1 related gene of Arabidopsis thaliana against V. dahliae. Bioinformatic analysis showed that the open reading frame length of GhERF020 was 441 bp, encoded 147 amino acids. GhERF020 contained a conserved AP2 domain, the relative molecular weight was 16.16 kD without transmembrane structure, belonging to the hydrophilic protein. It was predicted that the promoter region contained response elements of salicylic acid (SA), methyl jasmonate (MEJA), abscisic acid (ABA) and other response elements. The expression of GhERF020 was induced by V. dahliae infection. Subcellular localization analysis showed that GhERF020 protein was localized in the nucleus. As the expression of GhERF020 was downregulated by virus-induced gene silencing (VIGS) technique, the susceptibility of cotton plants to V. dahliae was significantly enhanced, and the disease index and pathogen biomass were distinctly increased. Above results indicated that GhERF020 was a positive regulator in resistance against V. dahliae in cotton.

    Identification and Biological Characteristics of a Colletotrichum fructicola Causing Chestnut Internal Rot Disease
    Shifeng MU, Xiaolei WEN, Lina FENG, Dexuan ZHAO, Suhong GAO, Peng GAO, Huixia QI
    2024, 26(9):  122-128.  DOI: 10.13304/j.nykjdb.2023.0871
    Asbtract ( )   HTML ( )   PDF (1614KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Chestnut internal rot is the main disease of chestnut during postharvest storage, which causes rot and mildew of chestnut kernel and brings huge economic losses to production. In order to clarify the pathogenic bacteria and its biological characteristics, the strain ZHZF21 was obtained by tissue isolation method. The strain was identified by morphological characteristics and ITSTUB2 and CAL multi-gene sequence analysis. The pathogenicity of strain ZHZF21 was determined by mycelial inoculation method, and its biological characteristics were studied. The results showed that the colony of strain ZHZF21 was dark green ring concentric circles, with sexual and asexual reproduction stages. This strain was clustered with Colletotrichum fructicola numbered NDSTY31 in GenBank based on multi-gene sequences. Combined with colony morphological characteristics and molecular tree, strain ZHZF21 was preliminarily identified as Colletotrichum fructicola. The brown lesions after inoculation of strain ZHZF21 were consistent with the natural symptoms. The strain ZHZF21 could grow at 5~35 ℃, the optimum temperature was 25 ℃, the lethal temperature was 45~50 ℃, and the optimum pH was 6. Under the condition of full darkness, strain ZHZF21 grew fastest, the utilization rates of arabinose and yeast were the highest, the utilization rate of lactose was the lowest, and urea could hardly be used.

    Impact of ExsA on the Pathogenicity of Aeromonas veronii
    Zihui CAI, Wenxin CHEN, Juanjuan LI, Hong LI, Xue CHI, Yanqiong TANG, Zhu LIU, Xiang MA
    2024, 26(9):  129-136.  DOI: 10.13304/j.nykjdb.2024.0316
    Asbtract ( )   HTML ( )   PDF (1704KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Aeromonas veronii is an important pathogen in the co-occurrence of humans and fish, causing significant mortality in various aquatic organisms, posing a major threat to aquaculture and public health care. The type Ⅲ secretion system (T3SS) is one of the most critical virulence mechanisms in determining the pathogenicity of Aeromonas species. The transcription factor ExsA of AraC family serves as the main regulatory factor and activates T3SS assembly and effector protein secretion in response to changes in environmental conditions. In order to explore the effect of exsA on the pathogenicity of the A. veronii, this study constructed an exsA gene knockout strain using homologous recombination strategy and tested its biofilm formation, adhesion capabilities, as well as the cytotoxicity of the spent cultural supernatant. The results showed that the deletion of the exsA gene in A. veronii led to a significant decrease of its biofilm formation capability, its adhesion to ex vivo host tissues, and the cytotoxicity of the spent culture supernatants. Compared with the wild type, the ability of the exsA knockout strain to form biofilm was reduced by 1.5 folds. The adhesion to epithelial cells was not significantly changed in exsA knockout strain as compared with the wild type, while the adhesion to ex vivo mouse intestinal tissues decreased by 3.4 folds and the cytotoxicity of bacterial culture supernatants decreases by 1.2 folds. These results proved that exsA plays an important regulatory role in the virulence mechanism of bacterial pathogen, laying a solid foundation for further research on the function of T3SS in the pathogenic mechanism of A. veronii and provided clues for establishing strategies for the control of the aquatic infection.

    FOOD QUALITY & PROCESSING AND STORAGE
    Effect of Different Storage Temperatures on Quality of Jingcai 1 Watermelon
    Lanting XIANG, Shuhui SONG, Lijuan LIU, Xiaoling SHE, Jiahua ZHOU, Baogang WANG, Hong CHANG, Chao ZHANG, Daqi FU, Yunxiang WANG
    2024, 26(9):  137-145.  DOI: 10.13304/j.nykjdb.2023.0685
    Asbtract ( )   HTML ( )   PDF (1639KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    To explore the effect of storage temperature on Jingcai 1 watermelon, the fruits of Jingcai 1 watermelon were storaged under 5, 15 and 25 ℃. The firmness, rate of weight loss, chilling injury, soluble solids, pectin, cellulose, soluble sugar, organic acid, lycopene, β?-carotene and vitamin C contents were determined under different temperature treatments. The results showed that, with the storage extending, the weight loss rate of Jingcai 1 watermelon fruit increased, the fruit firmness decreased, the content of water-soluble pectin (WSP) increased, the sodium carbonate-soluble pectin (SSP) decreased, the vitamin C, lycopene and β?-carotene showed decreasing trend, the variation of soluble solids fluctuated within a small rage, the cellulose decreased at first and then increased, while the content of soluble sugar and organic acid showed different changing trends at different storage temperatures. When stored at 5 ℃, the vitamin C and soluble sugar of fruit could be high level, but a long-term storage would raise the chilling injury rate and cause gradual wastage of nutrients, resulting undoubtedly in loss of the edible and commercial values. When stored at 15 ℃, the contents of water, organic acids and cytochromes could be better maintained, giving watermelons better quality and flavor. When stored at 25 ℃, the quick loss of soluble sugar, organic acid and pectin of the fruit leaded to soft rot, depriving original flavors of watermelons and making it difficult to maintain its quality. Above results provided a theoretical basis for the commercialization of its storage, transportation and preservation.

    Effects of High Hydrostatic Pressure Processing on Volatile Compounds in Cabernet Sauvignon
    Xueqing WANG, Bo ZHANG, Liting HAN, Zhuanzhuan LYU, Jianjun CHEN, Zhulin ZHANG, Junqiang ZHANG, Jianmei DU
    2024, 26(9):  146-158.  DOI: 10.13304/j.nykjdb.2022.1036
    Asbtract ( )   HTML ( )   PDF (2043KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    In order to improve the aroma quality of wine grape raw materials, the effects of different ultra-high pressure treatment conditions on the volatile substances of Cabernet Sauvignon grapes were studied. The headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) were used,and the characteristic aroma was studied with principal component analysis and aroma profile analysis. The results showed that, compared with the control, the volatile compounds in grapes under different treatment conditions changed significantly (P<0.05). Principal component analysis showed that the pressure operation of 400 MPa and the treatment conditions of 25 min were highly correlated with aldehydes and ketones with herbal and fruity smells in grapes. The aroma profile of volatile substances found that certain pressure and time treatment could significantly improve the odor intensity of grapes. Above results provided certain data references and technical support for applying and promoting high hydrostatic pressure technology in wine production.

    Effect of Glycosylation on Quality and Volatile Flavor Characteristics of rainbow trout (Oncorhynchus mykiss) Floss
    Lei JI, Tianhong LIU, Ying WANG, Xiao LI, Hongyan LI, Xiaodong JIANG, Yuanqin SUN, Shuaizhong ZHANG
    2024, 26(9):  159-172.  DOI: 10.13304/j.nykjdb.2023.0731
    Asbtract ( )   HTML ( )   PDF (1304KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    To promote the development of high-value products for rainbow trout (Oncorhynchus mykiss), the quality (physicochemical properties, color, and sensory properties) of rainbow trout floss with different sugars added were investigated. At the same time, the volatile components and fatty acids of the floss were analyzed by gas chromatography-mass spectrometer (GC-MS). The results showed that the addition of sugar had an important impact on the quality of rainbow trout floss, which could promote the process of Maillard reaction and improve the sensory quality of fish floss such as taste and color. As pentose, the fish floss with arabinose had a faster process of Maillard reaction and more obvious color change, while the fish floss with fructooligosaccharides had a better sweet taste. In terms of fatty acid, the contents of saturated fat acid, eicosapntemacnioc acid (EPA) and docosahexaenoic acid (DHA) of the fish floss with oligofructose were the highest, and the content of polyunsaturated fatty acid of the fish floss with arabinose was the highest. In conclustion, due to Maillard reaction, the fish floss added with sugar produced aldehydes, ketones, alcohols and other substances with lower threshold, which could impact the flavor. Above results provided reference for improving the quality of rainbow trout floss and increasing product added value.

    BIO-MANUFACTURING & RESOURCE AND ECOLOGY
    Comparative Study on Soil Organic Carbon and Its Components in Different Plant Community Types
    Yuanjie YU, Qingqing ZHANG, Jianguo MA, Kangwei JIANG, Hong LI
    2024, 26(9):  173-182.  DOI: 10.13304/j.nykjdb.2023.0047
    Asbtract ( )   HTML ( )   PDF (3235KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    In order to understand the effect of different plant communities on soil organic carbon content, 4 plant communities were selected in the middle of the northern slope of Tianshan mountains, including Picea schrenkianaIris loczyi shrub, Achnatherum inebrians and Malva rotundifoli. 5 samples of 1 m × 1 m were set in each community, and the soil samples were taken by 5-point for analyzing the content and constituent of total organic carbon in 0—10, 10—20, 20—30, 30—40 and 40—50 cm soil layers. The results showed that the soil organic carbon contents in 0—20 cm layer of 4 plant communities were higher, and decreased to be stable in 30—50 cm soil layers. The total soil organic carbon content of Picea schrenkiana was 244.24 g·kg-1, which was significantly higher than other communities with 86.62%, 20.66% and 41.32% increase to Iris loczyi shrub, Achnatherum inebrians and Malva rotundifoli, respectively. The organic carbon contents of 3 different oxidation degrees in 4 plant communities showed highly oxidizable organic carbon > difficult to oxidize organic carbon > easily oxidizable organic carbon. In 0—10 and 10—20 cm soil layers, the contents of highly oxidizable and the oxidizable organic carbon were higher in Achnatherum inebrians community. For the content of difficult to oxidize organic carbon, Malva rotundifoli community was higher in soil of 30—50 cm layer, Picea schrenkiana community was higher in soil of 10—20, 40—50 cm layers, Achnatherum inebrians community was higher in soil of 20—30, 30—40 cm layers. The contents of inert organic carbon in 4 communities were 48.61, 29.46, 54.46 and 39.17 g·kg-1, respectively, accounting for about 20% of the total organic carbon. It indicated that different plant community in the northern slope of Tianshan mountains would affect the contents, composition and spatial distribution of soil organic carbon. As a sensitive indicator of soil carbon content dynamic change, soil organic carbon could timely reflect the turnover and dynamic change process of soil organic carbon pool.

    Effect of Acid Modified Biochar on Infiltration Characteristics of Coastal Saline Soil
    Danyi SHI, Yu QIU, Chengzhen HUANG, Juan WANG
    2024, 26(9):  183-192.  DOI: 10.13304/j.nykjdb.2023.0113
    Asbtract ( )   HTML ( )   PDF (3667KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    To study the effects of conventional biochar and acid modified biochar on water infiltration, with no biochar as the control (CK), 2 kinds of biochar with 3 additive amounts of 2%, 4% and 8% (mass fraction) were set up to conduct vertical one-dimensional water infiltration test. The dynamic changes of cumulative infiltration amount and wetting front migration were measured and discussed. The results showed that biochar increased the cumulative infiltration volume, shortened the wetting front transport time and improved the infiltration rate, and the larger the amount of biochar added, the more obvious the effect. Biochar improved the water holding capacity of coastal saline soils, and the effect of acid modified biochar on increasing the water content of shallow soil was more obvious. The one dimensional algebraic model was suitable for the water content of the tillage layer of coastal saline soil after the addition of biochar, and simulated the water distribution of the soil tillage layer after the infiltration test. Overall, the addition of 4% acid modified biochar was beneficial for improving the infiltration capacity and water holding characteristics of coastal saline soils.

    Effect of One-off Fertilization on Yield and Nitrogen Fertilizer Efficiency of Summer Maize in Different Ecological Regions
    Wenxuan SHI, Jinfang TAN, Qian ZHANG, Lantao LI, Yilun WANG
    2024, 26(9):  193-202.  DOI: 10.13304/j.nykjdb.2022.1099
    Asbtract ( )   HTML ( )   PDF (1017KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    To study the effects of one-off application of slow-release nitrogen (N) fertilizer or controlled release urea on yield, N utilization efficiency and economic benefits of summer maize in Huanghuai regions, field experiments with one-off fertilization of controlled release urea or slow release urea blended with normal urea were conducted at 6 experimental sites in Henan province in 2021. 9 treatments were set under field condition: no nitrogen fertilizer (CK), normal urea alone (U1), farmers’ fertilization practices (U2), controlled release urea blended with normal urea (CRU) including 3 ratios of 3∶7 (CRU1), 5∶5 (CRU2), 7∶3 (CRU3) , slow release urea blended with normal urea (LCU) including 3 ratios of 3∶7 ( LCU1), 5∶5 (LCU2) and 7∶3 (LCU3). The effects of controlled release urea or slow release urea blended with normal urea on yield, N utilization and economic efficiency of summer maize were studied. The results showed that N application treatments increased yield by 11.6%~49.1% compared with CK. The average yield of N application treatments was in the order of CRU>LCU>U(U1、U2). The average yield of CRU and LCU was 23.3% and 9.7% higher than U, respectively, with CRU2 having the highest yield of 9 444.0 kg·hm-2, 8.0%~33.6% higher than other N application treatments, followed by LCU2. Dry matter accumulation, grain number per spike and 1 000-grain weight were significantly higher under CRU and LCU treatments compared with U. The highest N recovery efficiency was 36.9% under CRU2 treatment, followed by LCU2 at 33.2%. Compared with U, CRU and LCU treatments had higher NO3--N content in 0—40 cm and significantly lower NO3--N content in deeper soils (40—100 cm), which resulted in an average revenue increase of 2 186 and 995 yuan·hm-2, respectively. The sustainable yield index of summer maize was correlated with high yield and coefficient of variation. CRU2 and LCU2 treatments had more stable yields and better sustainability. Combining yield, N utilization and economic efficiency, the N fertilizer management model of 5∶5 combination of controlled release urea and normal urea was recommended for one-off application in summer maize production in Huanghuai regions. Above results could provide a basis for simplified production techniques of summer maize and high yield and efficiency of N fertilizer.

    Spatial Pattern and Interspecific Association of Natural Platycladus orientalis Population in Loess Hilly Region of Inner Mongolia
    Jiajia SONG, Yunxia MA, Jingjie GUO, Baomengkenashun, Zhonghou GU, Kun LIU, Zhilong LI, Shengli HAN, Xia KANG, Rewadi
    2024, 26(9):  203-212.  DOI: 10.13304/j.nykjdb.2022.1034
    Asbtract ( )   HTML ( )   PDF (4153KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    In order to explore the spatial distribution pattern and intra-specific correlation of Platycladus orientalis population in the Loess hilly region of Inner Mongolia, the natural Platycladus orientalis sparse forest in the typical Loess hilly region of Inner Mongolia was taken as the research object, and the spatial pattern of Platycladus orientalis population in different slope directions was analyzed using the point pattern combined with the complete spatial randomness, the heterogeneous Poisson model and the Poisson aggregation model of the single variable function, and the intra-specific grade was determined after the availability of the age class was determined by the fitting curve, a bivariate function was constructed to study the intra-specific correlation of Platycladus orientalis population.The results showed that the resources of regenerated seedlings were abundant, followed by young trees, and the number of mature trees was the least. The proportion of grade Ⅰ was as high as 27.79%, grade Ⅱ was 21.84%, and the cumulative proportion of grade Ⅲ to grade Ⅴ was 32.85%. The population distribution of each age class was pyramidal, and the population structure was stable, showing a steady growth trend.The quantity distribution of each age of 4~22 m, and the shady slope presents a small scale of 0~1 m aggregation distribution. The heterogeneous Poisson model showed that the slope direction had an impact on the aggregation degree of Platycladus orientalis population, and the Poisson aggregation model had an aggregation distribution within the range of 1~5 m, indicating that there was a certain relationship between species. There were 3 kinds of correlations in Platycladus orientalis species. The relationship between seedlings and adult trees was positive within 0~1 m of the scale of shady slope and semi-shady slope. The relationship between young trees and adult trees was completely in the confidence interval of sunny slope. The relationship between young trees and adult trees was negative at 6~7 and 3~4 m under the conditions of semi-shady slope and semi-sunny slope, respectively. The relationship between young trees and adult trees was negative at shady slope, semi-shady slope and semi-sunny slope, and the sunny slope was not negative relationship. To sum up, in addition to its own biological characteristics, the impact of microenvironment and intra-specific competition on the distribution of Platycladus orientalis population in the loess hilly area was also very important. Above results provided a basis for the planting and management of Platycladus orientalis and its habitat adaptability.

    Effects of Ecological Factors on Quality Difference Between Forestland Ginseng and Farmland Ginseng
    Zhefeng XU, Chunshuo LIU, Xudong LIAO, Jiahong SUI, Yuqiu CHEN, Changbao CHEN, Tao ZHANG, Lina WEI
    2024, 26(9):  213-223.  DOI: 10.13304/j.nykjdb.2023.0081
    Asbtract ( )   HTML ( )   PDF (4007KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    The ecological environment is an important influencing factor that leads to differences in the quality of forestland ginseng and farmland ginseng. The content of ginsenosides in forestland ginseng and farmland ginseng was used as an indicator to analyze their quality differences, determined the physicochemical properties of rhizosphere soil, and conducted correlation, multiple stepwise regression, coefficient of variation, partial least squares discriminant analysis, and analytic hierarchy process comprehensive evaluation analysis on the measurement results. The results showed that there were significant differences in ginsenoside content and soil physicochemical properties between forestland ginseng and farmland ginseng. Analysis of coefficient of variation showed that the coefficient of variation of most ecological factor indicators in farmland ginseng was greater than that in forestland ginseng. The results of correlation, multiple stepwise regression, and partial least squares discriminant analysis showed a significant correlation between soil factors such as the highest temperature, the lowest temperature, pH, alkaline nitrogen, and available phosphorus with ginsenosides. The results of the analytic hierarchy process showed significant differences in soil quality among different cultivation modes. Multiple statistical results showed that the highest temperature, the lowest temperature, and pH were the main factors affecting the content of ginsenosides, while alkaline nitrogen, available phosphorus, and soil moisture were secondary factors. Above results indicated that the highest temperature, the lowest temperature, pH, alkaline nitrogen, available phosphorus, and soil moisture were important factors affecting the quality differences between forestland ginseng and farmland ginseng. The results provided a theoretical basis for analyzing the formation of ginseng quality and planting production.

    Effects of Microorganisms from Different Sources on the Composting Process of Grape Branches and Pig Manure
    Jiping WANG, Tiedong LU, Zhiheng LIANG, Ye ZHANG, Tianming SU, Tieguang HE
    2024, 26(9):  224-233.  DOI: 10.13304/j.nykjdb.2022.0926
    Asbtract ( )   HTML ( )   PDF (3420KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    In order to explore the influence of microorganisms from different sources on the composting process of grape branch and pig manure, 3 treatments were set including no external microorganisms (CK), inoculated biogas slurry (T1), and inoculated microbial inoculum (T2). The temperature, moisture content, pH, electrical conductivity (EC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), seed germination index (GI), bacterial and fungal communities were analyzed during the composting process to determine the key microbial in the composting process. The results showed that the temperature of T1 was higher than that of T2 treatment in the early stage of composting with over 45 ℃ at the 3rd day, and the maximum temperature all reached 60 ℃ in 3 treatments. The changes of moisture, pH, EC and nutrient content of compost in each treatment were consistent, and the contents of TN, TP and TK were 3.43%~3.59%, 1.46%~1.56% and 1.87%~2.02%, respectively. The moisture content, pH and EC of compost in T2 were higher than those in other treatments after composted. The germination indexes of CK and T1 treatment exceeded 70% on the 30th day, and reached the organic fertilizer standard faster than T2 treatment. The results of microbial community analysis showed that the relative abundance of Proteobacteria and Firmicutes exceeded 75% in the early stage, Firmicutes was the dominant phylum in the middle stage, and the relative abundances of Bacteroides and Deinococcus-Thermus increased in the middle and final stages, and their final proportions exceeded 20%. There were significant correlations between Firmicutes, Bacteroides, Deinococcus-Thermus and indicators of composting. The analysis of contribution degree showed that the total contribution degree of microbial community to composting was 33.90%, and the contribution degree of Gemmatimonadetes was 80.80%. Above results provided a reference for further research and screening of special antioxidant resistant microorganism inoculants.