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25 March 2022, Volume 34 Issue 3 Previous Issue    Next Issue
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Crop Science
Animal Science
Horticultural Science
Plant Protection
Environmental Science
Biosystems Engineening
Agricultural Economy and Development


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Contents 2022, 34(3):  0.  Abstract ( 325 )   PDF (35954KB) ( 638 )   Related Articles | Metrics

Crop Science

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Effect of plant density on canopy structure and population photosynthetic capacity of rapeseed with different plant heights LI Hongqiao, LAI Ying, MU Na, YAN Hongmei, TANG Weiqun, JIANG Xiaoling, GAO Wen, WU Yongcheng 2022, 34(3):  419-427.  DOI: 10.3969/j.issn.1004-1524.2022.03.01 Abstract ( 570 )   HTML ( 418620 )   PDF (945KB) ( 796 )   To explore the characteristics of canopy structure and population photosynthetic capacity of Brassica napus with different planting densities under the late direct sowing. A two-factor split plot design was adopted, under the rice-rapeseed rotation system in the Chengdu Plain, with different planting densities (150 000 plants·hm-2, 300 000 plants·hm-2, 600 000 plants·hm-2 expressed as D1, D2, and D3, respectively) as the main factor, and different rapeseed varieties (semi-dwarf rapeseed Jiayou JS-1 and high-stalk rapeseed Chuanyou 36, represented by V1 and V2, respectively) were secondary factors.Leaf area index (LAI), pod area index (PAI), light transmittance, population photosynthetic rate, biomass and grain yield of the plant population under the field experiment were measured. The results showed that during the flowering period, LAI of V1 increased first and then decreased with the increase of planting density, and LAI of V2 increased with the increase of density;During grain grouting stage, PAI increased significantly with the increase of planting density. During the flowering stage, with the increase of planting density, transmittance of V1 did not change significantly, while the transmittance of V2 showed a decreasing trend; The increase of planting density at grain grouting stage resulted in a significant decrease in the transmittance between the rows of V1 and V2. And transmittance of V1was significantly higher than that of V2 under the same density.The population photosynthetic rate (photosynthetic rate of all rapeseed plants per unit area) of V1D3 in the flowering period was 43.42 μmol·m-2·s-1, which increased by 27.33% and 9.72% compared to D1 and D2; The population photosynthetic rate of V1D3 in the grouting period was 28.24 μmol·m-2·s-1, increased by 37.55% and 7.05%compared with D1 and D2. Population photosynthetic rate was V1>V2 and the differences were significant under higher planting density (D2, D3).In conclusion, increasing planting density stimulated the population photosynthetic area index of late direct seeding rapeseed, which was beneficial to the construction of good canopy structure, and enhanced population photosynthetic rate and grain yield of rapeseed. Compared with high-stalk rapeseed (average 2 365.48 kg·hm-2), semi-dwarf rapeseed had higher population light transmittance and population photosynthetic rate, and higher harvest index under the late direct seeding and high density, which resulted in higher grain yield (average 3 057.32 kg·hm-2). Figures and Tables | References | Related Articles | Metrics

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Effects of synergy by double genes of PjFPS and Pjβ-AS on biosynthesis of Panax japonicus saponins CHEN Qin, LIU Meijia, LIU Diqiu, QU Yuan, CUI Xiuming, GE Feng 2022, 34(3):  428-436.  DOI: 10.3969/j.issn.1004-1524.2022.03.02 Abstract ( 424 )   HTML ( 1200 )   PDF (1067KB) ( 664 )   Farnesyl pyrophosphate synthase (PjFPS) and β-amyrin synthase (Pjβ-AS)are key enzymes in the biosynthetic pathway of Panax japonicus saponins (PJS). In this study, effects of PjFPS and PjβAS on PJS biosynthesis were investigated by overexpressing PjFPS and Pjβ-AS simultaneously in P. japonicus cells. The results showed that PjFPS and Pjβ-AS were key enzyme genes in PJS biosynthetic pathway and had regulatory effects on biosynthesis of P. japonicus. The cell lines overexpressing PjFPS and Pjβ-AS showed differential increases in the expression levels of several key enzyme genes related to the PJS synthesis pathway, and the highest levels of PJS were up to 2.4 times higher than those of the normal cell lines. Although overexpression of PjFPS alone also increased PJS synthesis, dual genes (PjFPS and Pjβ-AS) synergistically regulated PJS synthesis more effectively. Figures and Tables | References | Related Articles | Metrics

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Analysis of aroma characteristics of Longjing tea made from different tea cultivars WU Xiaoqing, ZHOU Feifei, YE Ying, HUANG Yanmei, YANG Leiyu, HUANG Haitao, WU Yuanyuan 2022, 34(3):  437-446.  DOI: 10.3969/j.issn.1004-1524.2022.03.03 Abstract ( 377 )   HTML ( 572 )   PDF (3625KB) ( 851 )   Longjing tea is one of the traditional high-grade tea in China. The tea cultivars have a significant effect on the aroma quality of Longjing tea. In this study, the aroma of 20 varieties of Longjing tea was evaluated by tea sensory evaluation method. The headspace solid-phase microextraction and gas chromatography-mass spectrometry (HS-SPME/GC-MS) was used to analyze the relative contents of aroma compounds from 20 Longjing tea samples which were made from different tea cultivars. A total of 74 main aroma components were detected from these samples. By the partial least squares discriminant analysis (PLS-DA), significant differences in the chemical composition of aroma components from different Longjing tea samples were found and characterized as different aroma types. Jiukeng single plant clone cultivars J1132, J1137, J1142, JK8, JK12, JK211, and LF Longjing tea samples were rich in volatile components with chestnut aroma, which were easy to process Longjing tea with chestnut flavor. The aroma types of Longjing tea samples made from different Longjing cultivars were also different. Tea samples of L2 and L5 were characterized with chestnut fragrance, LJ43 sample was fresh fragrance, ZC108, LJCY were floral fragrance. Fuyun hybrid cultivars were easy to process floral fragrance Longjing. Figures and Tables | References | Related Articles | Metrics

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Investigation and evaluation of Litsea coreana germplasm resources in Chongqing DAI Qianli, ZHU Hengxing, LU Min, HUANG Feiyi, CHEN Benwen, CHEN Qin, YIN Siqin, ZHU Yuanchun 2022, 34(3):  447-456.  DOI: 10.3969/j.issn.1004-1524.2022.03.04 Abstract ( 392 )   HTML ( 551 )   PDF (874KB) ( 824 )   To objectively evaluate germplasm resources of Litsea coreana in Chongqing,morphological indexes of 123 germplasm resources were investigated. 27 germplasm resources were selected to determine the water extract, tea phoyphenol, total flavonoid, free amino acid and soluble sugar contents.The ranking of biochemical indexes assessment for different germplasm resources was determined by grade and factor evaluating methods. Among these germplasm resources, the average content of water extract was 29.25%, while the maximum was 37.10% (WX18) and the minimum was 22.60%(WL32). The average content of tea phoyphenol was 11.25%, while the maximum was 14.07%(WX4) and the minimum was 9.87%(NC2). The average content of total flavonoid was 1.65%, while the maximum was 2.66%(WX22) and the minimum was 1.03%(NC9).The average content of free amino acid was 0.98%, while the maximum was 1.40%(WX12) and the minimum was 0.73%(WX22). The average content of soluble sugar was 4.73%, while the maximum was 6.35%(WX18) and the minimum was 3.06%(WL30).There were differences in contents of water extract, tea phoyphenol, total flavonoid, free amino acid and soluble sugar among the fresh leaves from different Litsea coreana germplasm resources. These biochemical indexes could be used as indicators for the preliminary evaluation of the germplasm resources.WX18, WX22, WX20, WL40 and WX21 were the top 5 in overall ranking,they were considered as elite germplasm resources.WX18 and WX22 could be used as red-purple bud germplasm resources, WX20 and WX21 could be used as pink bud germplasm resources, and WL40 could be used as new yellow-green bud germplasm. Figures and Tables | References | Related Articles | Metrics

Animal Science

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Establishment of a duplex fluorescent quantitative PCR assay for detection of porcine circovirus type 2 and type 3 MOU Hongye, ZHOU Xiaojie, YANG Yongchun, WANG Xiaodu, ZHOU Yingshan, SONG Houhui 2022, 34(3):  457-463.  DOI: 10.3969/j.issn.1004-1524.2022.03.05 Abstract ( 612 )   HTML ( 223 )   PDF (1413KB) ( 677 )   To establish a method for simultaneous detection of porcine circovirus type 2 (PCV2) and porcine circovirus type 3 (PCV3),specific primers and TaqMan probes were designed after sequence alignment according to the specific sequences of PCV2 Cap gene and PCV3 Cap gene on GenBank. By optimizing the reaction conditions, a duplex fluorescence quantitative PCR detection method for simultaneous detection of porcine circovirus type 2 and 3 was established, and the specificity, sensitivity, and reproducibility were tested.Specificity test results showed that in addition to the positive test results for PCV2 and PCV3, tests for PRRSV, CSFV, PPV, PRV, PEDV, and TGEV were all negative with no cross-reaction, indicating its good specificity. Sensitivity test results showed that the minimum detection limit for detection of PCV2 and PCV3 can both reach 10 copies·μL-1, indicating its high sensitivity. The coefficient of variation within and between groups of this method was less than 2%, indicating its good stability. A total of 181 pork and whole blood samples collected from Zhejiang Province were tested using the detection method established in this article and the standard common fluorescent PCR detection method. The results showed that the positive rate of PCV2 was 50.83% (92/181),the positive rate of PCV3 was 37.57% (68/181), and the co-infection rate of PCV2 and PCV3 was 12.15% (22/181).The above detection results of ordinary fluorescent PCR were 50.28% (91/181), 36.46% (66/181), and the co-infection rate was 11.60% (21/181).The coincidence rates of the two methods for PCV2 and PCV3 can reach 98.91% and 97.06%, and the coincidence rate for PCV2 and PCV3 mixed infection were 95.45%. In summary, the duplex fluorescence quantitative PCR detection method established in this experiment can distinguish PCV2 and PCV3 rapidly, which can be used for pathogen detection and epidemiological investigation. Figures and Tables | References | Related Articles | Metrics

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Effect of glucose concentrations on proinflammatory cytokine released from bovine alveolar macrophages TAN Tianyu, CAI Dongjie, WANG Zhisheng, ZUO Zhicai 2022, 34(3):  464-470.  DOI: 10.3969/j.issn.1004-1524.2022.03.06 Abstract ( 365 )   HTML ( 37 )   PDF (700KB) ( 688 )   In order to investigate whether changes in glucose concentration can up-regulate the RAGE-TLR4-MyD88-NF-κB signaling pathway of bovine alveolar macrophages (BAMs) and cause BAMs to release proinflammatory cytokines IL-1β, IL-6 and TNF-α.Groups Ⅰ, Ⅱ, Ⅲ and Ⅳ were treated with 5.5, 15.5, 25.5 mmol·L-1 glucose and glucose (5.5 mmol·L-1)+mannitol (20 mmol·L-1) for 12 h to collect the cultured cells and supernatants; and 25.5 mmol·L-1 glucose and BAMs were used for 0, 3, 6, 12, 24 h to collect the cultured cells and supernatants at each time point.RAGE, TLR4, MyD88 and NF-κB p65 mRNA levels and IL-1β, IL-6 and TNF-α concentrations in the supernatant were detected.The results showed that the levels of RAGE, TLR4, MyD88 and NF-κB p65 mRNA and the concentrations of IL-1β, IL-6 and TNF-α in group Ⅲ were significantly (P<0.01)higher than those in group Ⅰ, the concentrations of IL-1β and TNF-α in group Ⅱ were significantly(P<0.01) higher than those in group Ⅰ, the levels of MyD88, TLR4 and NF-κB p65 mRNA were significantly (P<0.05)higher than those in group Ⅰ at 3 h, and RAGE was significantly (P<0.05)higher than that at 6 h.The four gene indices all reached the peak at 12 h, which was significantly (P<0.01)higher than other time points.Only RAGE and NF-κB p65 at 24 h were significantly(P<0.01) higher than 0 h. The concentrations of IL-1β, IL-6 and TNF-α were significantly (P<0.05)higher after 3 h than 0 h, and showed a time-dependent peak at 24 h. In conclusion, 25.5 mmol·L-1 glucose can up-regulate the gene expression in the BAMs RAGE-TLR4-MyD88-NF-κB signaling pathway and promote the release of proinflammatory cytokines IL-1β, IL-6 and TNF-α. Figures and Tables | References | Related Articles | Metrics

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Prediction of target genes and tissue expression analysis of miR-144 in cattle DING Yanling, WANG Pengfei, YANG Chaoyun, ZHOU Xiaonan, ZHAO Zhiyan, ZHANG Yanfeng, SHI Yuan- gang, KANG Xiaolong 2022, 34(3):  471-479.  DOI: 10.3969/j.issn.1004-1524.2022.03.07 Abstract ( 484 )   HTML ( 271 )   PDF (984KB) ( 752 )   To study the target genes of miR-144 and their expression patterns in different tissues of cattle, and to predict the regulatory mechanism of miR-144 on muscle growth and development, the conservation, potential target genes and their enrichment pathways of miR-144 among different species were analyzed, and expression of miR-144 in different tissues of cattle was detected by qRT-PCR. The results showed that mature sequence of miR-144 was highly conserved among species; Enrichment analysis showed that target genes were significantly enriched in vascular smooth muscle contraction, cGMP-PKG, cAMP and other pathways related to muscle development. qRT-PCR results showed that miR-144 had the highest expression in liver and the lowest expression in subcutaneous fat; There was no significant difference(P>0.05) in the expression of miR-144 in leg muscle and heart, but the expression of miR-144 in liver was significantly (P<0.05) higher than that in leg muscle and heart; The expression of miR-144 in longissimus dorsi was significantly (P<0.05) higher than that in rumen and subcutaneous adipose, but there was no significant difference (P>0.05) between rumen and subcutaneous adipose. Figures and Tables | References | Related Articles | Metrics

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Expression and distribution of THRβ mRNA and protein in HPO axis of Ganja Tibetan sheep during estrus cycle and anestrus LIU Lili, GAO Hexuan, YANG Yawen, BAO Yingying, HE Yuqin, YANG Zhijie, CHEN Weigang, GE Wenbo 2022, 34(3):  480-488.  DOI: 10.3969/j.issn.1004-1524.2022.03.08 Abstract ( 244 )   HTML ( 14 )   PDF (20132KB) ( 623 )   Thyroid hormone (TH) exerted its biological effects by specifically binding to its target cell receptor. In order to clarify the regulation of thyroid hormone receptor β (THRβ) gene and its protein in the pineal gland and Hypothalamic-pituitary-ovary (HPO) axis of the reproductive activity of seasonal breeding animals, Ganjia Tibetan sheep (Ovis aries). In this study, the healthy Ganjia Tibetan sheep during the estrus cycle and anestrus were used as the research object. RT-qPCR, Western blot and immunohistochemical staining were used to detect and analyze the expression and distribution of THRβ mRNA and its protein in the pineal gland and HPOA. The results showed that THRβ mRNA and its protein were expressed and distributed in the pineal gland and HPOA tissues. The expression of THRβ mRNA and its protein in the pineal gland in the anestrus were significantly (P<0.05) higher than that in the estrus cycle. In hypothalamus, the expression of THRβ mRNA in the metestrus were significantly (P <0.05) higher than that in other stages while the expression of its protein in the disestrus were significantly (P<0.05) higher than that in other stages; In pituitary gland, the expression of THRβ mRNA and its protein in the diestrus were significantly (P<0.05) higher than that in other stages. In ovary, the expression of THRβ mRNA and its protein in the metestrus were significantly (P<0.05) higher than that in other stages. The immunohistochemical results showed that THRβ was mainly distributed in the eosinophilic cytoplasm of the pineal, glial cells, large neuron cell bodies and vertebral cell cytoplasm of the hypothalamic, eosinophilic and basophilic cytoplasm of adenohypophysis, granulosa cell cytoplasm, follicular inner membrane cells and luteal cells of the ovary. THRβ mRNA and its protein in the pineal gland and HPOA showed different changes during the estrus and anestrus, which indicated that THRβ gene and its protein were involved in the regulation of the reproductive activities of the Ganjia Tibetan sheep. Figures and Tables | References | Related Articles | Metrics

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Expression of Brucella ribosomal L7/L12 protein and its effect on mouse derived dendritic cells ZHANG Guanglin, XU Long, GAO Yunyan, LI Lingxia, SHANG Youjun, ZHANG Yong, CAO Xiao’an2, ZHAO Xingxu 2022, 34(3):  489-497.  DOI: 10.3969/j.issn.1004-1524.2022.03.09 Abstract ( 514 )   HTML ( 17 )   PDF (2450KB) ( 634 )   In order to study the effect of ribosomal L7/L12 protein of Brucella on the differentiation and maturation of mouse dendritic cells (BM-DCs), the L7/L12 gene was amplified using Brucella S2 vaccine strain as template,and the recombinant plasmid pET30a-L7/L12 was constructed. The recombinant plasmid pET30a-L7/L12 was induced in E. coli prokaryotic expression system, and the expressed protein was purified by Ni column. Mouse-derived DCs was induced by IL-4 and GM-CSF, and the changes of costimulatory molecules and inflammatory factors on the surface of DCs were detected after DCs was stimulated by LPS and L7/L12 proteins. The results showed that the recombinant protein was highly expressed in soluble form under the condition of 1 mmol·L-1 IPTG and overnight at 16 ℃. The size of the recombinant protein was 18 ku, the purity was more than 93% and had certain reactivity. Flow cytometry showed that the expression of CD40, CD80 and other antigen molecules on the surface of stimulated BM-DCs cells was significantly (P<0.05) higher than that of the blank control group. The results of qPCR showed that the levels of inflammatory cytokines TNF-β, IL-1 β and IL-12 in the control group were significantly (P<0.01) higher than those in the control group. Recombinant L7/L12 protein can stimulate the differentiation and maturation of DCs cells and promote the release of inflammatory factors. Figures and Tables | References | Related Articles | Metrics

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Screening of genes related to auto-sexing on feather color based on RNA-seq technology WANG Qiankun, ZHANG Xiaohui, PANG Youzhi, QI Yanxia, LEI Ying, BAI Junyan, HU Yunqi, ZHAO Yiwei, YUAN Zhiwen, WANG Tao 2022, 34(3):  498-506.  DOI: 10.3969/j.issn.1004-1524.2022.03.10 Abstract ( 547 )   HTML ( 188 )   PDF (1291KB) ( 921 )   The phenomenon of auto-sexingby feather color in quail is determined by genes on the sex chromosomes, but the specific molecular mechanism is unknown. In this study, Beijing male white feather quail and female maroon feather quail were selected as research animals.The transcriptome of F1 male and F1 female quails at the 10th day of embryo stage were analyzed by RNA-seq technique, and the key genes associated with feather color were screened and verified by qRT-PCR. The results showed that a total of 38.94 G of raw reads were obtained in RNA-seq, with an average of 6.49 G for each sample. And the Q30 of the six libraries was above 90%, average of GC content was 49.7%.At least 89% of the reads from the tested sample were aligned to the reference genome.A total of 16 013 genes were obtained through database comparison, of which 69 were up-regulated genes and 22 were down-regulated genes.GO enrichment analysis revealed that 13 841 genes were annotated into the GO database, including 78 differentially expressed genes.KEGG enrichment results showed that 22 differentially expressed genes were enriched in 38 pathways. All differentially expressed genes were screened and seven genes related to feather color phenotype were obtained: DCT, MLANA, SLC45A2, TYRP1, TRPM1, FAM174A and KIT. According to the results of qRT-PCR, the candidate genes were highly expressed in maroon feather quail, which was consistent with RNA-seq results.The seven candidate genes obtained in this study might be related to auto-sexing. Figures and Tables | References | Related Articles | Metrics

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Screening and functional analysis of differentially expressed genes in breast muscle transcriptome between Plateau raindrop pigeon and Janssen pigeon LAN Guoxiang, JIN Siqi, LI Xingrun, LIU Xiyu, LI Guomei, DONG Xinxing 2022, 34(3):  507-516.  DOI: 10.3969/j.issn.1004-1524.2022.03.11 Abstract ( 510 )   HTML ( 229 )   PDF (1906KB) ( 799 )   Screening key genes for the difference in pectoral flight ability between Plateau raindrop pigeon and Janssen pigeon can lay foundation for breeding pigeons. Each 3 Plateau raindrop pigeons (JG) and Janssen pigeons (JS) with the same sex, similar body condition and age were selected. After slaughter, breast muscle tissues were taken for transcriptome sequencing and then differentially expressed genes (DEGs) were screened, Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and protein interaction network analysis were performed on the DEGs. The results showed that there were 75 significantly DEGs in the breast muscle transcriptome between JG and JS, including 49 up-regulated genes and 26 down-regulated genes. GO enrichment analysis results showed that DEGs were enriched in items such as skeletal muscle cell differentiation, regulation of cellular metabolic process. KEGG pathway analysis showed that DEGs were significant enriched in insulin signaling pathway, AMPK signaling pathway, etc. Compared with the JS,SMYD1, STAT1, VEGFA, PPM1K and PLCE1 genes in breast muscle of the JG were up-regulated, while MYOD1, SOCS3 and MGLL genes were down-regulated. The results showed that STAT1 and MYOD1 might cause breast muscle growth of JG to be slower than that of JS. SOCS3 might cause muscle fiber diameter of the breast muscle of the JG to become smaller and explosive power to decrease at the same time. PLCE1 might cause increase of muscle fibers in the breast muscle of JG. SMYD1 might cause muscle fiber differentiation to form more red muscle fibers. VEGFA might cause white adipose in JGs to be converted into brown adipose. PPM1K and MGLL might catalyze the decomposition of branched chain amino acids, providing enough energy for the long-distance load-bearing flight of the JG, which made they more suitable for long-distance flight. Figures and Tables | References | Related Articles | Metrics

Horticultural Science

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Effects of low temperature and weak light stress on leaf area and dry matter of cucumber in greenhouse TANG Weidong, LIU Zhenwen, LIU Dongsheng, HU Xuehua 2022, 34(3):  517-524.  DOI: 10.3969/j.issn.1004-1524.2022.03.12 Abstract ( 868 )   HTML ( 192 )   PDF (1165KB) ( 903 )   To study the change rules of leaf area and dry matter weight of cucumber with different leaf ages under low temperature and weak light stress, cucumber variety Biyu 3 was used as the test material, four treatment levels of low temperature and weak light were set, changes of leaf area, dry matter weight with different leaf ages were measured. The results showed that low temperature stress had a great effect on morphological development of leaves less than 15 days old, compared with the control, the decrease of leaf area was relatively large, but the effect on leaves aged 15-25 days was small; Under moderate low temperature (10-15 ℃) and weak light (photosynthetic photon flux density, PPFD 100-200 μmol·m-2·s-1), growth of leaf area decreased significantly and dry matter weight of leaves increased in the extension stage (5-15 d); The morphological development of leaves less than 15 days was basically stagnated under severe low temperature (5-10 ℃) and weak light (0-100 μmol·m-2·s-1), compared with the control, the decrease of leaf dry matter weight was relatively large; Mild low temperature and weak light stress (15-20 ℃, PPFD 200-400 μmol·m-2·s-1) did not significantly threaten the normal development of cucumber leaves, especially had little effect on the growth of leaf area and dry matter accumulation at the early stage of development. The results showed that in order to ensure the normal growth of leaves from the early stage of development to the expansion stage, moderate or above low temperature and weak light stress (5-15 ℃, PPFD 0-200 μmol·m-2·s-1) should be avoided. Figures and Tables | References | Related Articles | Metrics

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Effect of prunning patterns on canopy light interception characteristics and chlorophyll fluorescence parameters in cherry tomato WANG Huiru, LI Jianshe, YAN Sihua, GAO Yanming 2022, 34(3):  525-533.  DOI: 10.3969/j.issn.1004-1524.2022.03.13 Abstract ( 412 )   HTML ( 2514 )   PDF (924KB) ( 918 )   To elucidate the effects of prunning patterns on canopy photosynthetically active radiation, chlorophyll fluorescence parameters and yield, Xiangfei No.3 was selected as the experimental material, four levels were set for prunning patterns, canopy light interception characteristics, chlorophyll fluorescence characteristics, canopy microenvironment, growth indices and yield of plants were measured. As a result, in terms of colony canopy photosynthetically active radiation, the photosynthetic effective radiation (IPAR) and light interception rate (CaR) of plants in the three-bar prunning treatment was significantly (P<0.05) higher than other treatments, light transmittance (PeR) was on the contrary. In terms of leaf photosynthetic fluorescence characteristics, chlorophyll fluorescence parameters (Fv/Fm, qP) had different degrees of improvement than other treatments. At the same time,plants growth indices,canopy microenvironment and yield of three-bar prunning treatment was significantly (P<0.05) higher than other treatments. It can be seen that three-bar prunning was the most beneficial to form a reasonable individual configuration and population space arrangement, so as to improve the photosynthesis, growth status and yield of cherry tomato. Figures and Tables | References | Related Articles | Metrics

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Comprehensive evaluation of fruit quality and nutrition of six kumquat varieties YANG Lei, HONG Lin, LIU Zhaojun, YANG Haijian, WANG Wu 2022, 34(3):  534-547.  DOI: 10.3969/j.issn.1004-1524.2022.03.14 Abstract ( 1057 )   HTML ( 1633 )   PDF (1222KB) ( 949 )   To study the difference of fruit quality and nutrition of different kumquat varieties, 15 main quality indexes, 20 functional component indexes and 17 amino acid nutrition indexes of six kumquat varieties from National Fruit Germplasm (Chongqing) Citrus Nursery were determined as the research object, and comprehensive evaluation was made by combining principal component analysis and membership function method. The results showed that fruit essential quality of Fortunella obovata(Wenguangju) was much better, total flavonoids content of Fortunella classifolia(Huapi) was the highest, Fortunella obovata(Wenguangju) and Fortunella classifolia(Huapi) had high total phenolic acids content. both of Fortunella japonica(Luowen) and Fortunella classifolia(Rong’an) had higher total amino acid content. Efficacy, bitter and aromatic amino acid content of Fortunella classifolia(Huapi)was the highest, and sweet amino acid content of Fortunella classifolia(Rong’an) was the highest. Four principal components were extracted through the principal component analysis (PCA), and the contribution rate reached to 98.905%, then the membership function method was used to obtain comprehensive evaluation values of fruit quality and nutrition of six kumquat varieties, the final score ranking was: Fortunella obovata (Wenguangju)> Fortunella japonica(Ningbo)> Fortunella classifolia(Huapi)> Fortunella crassifolia(Wenzhou)> Fortunella margarita(Ningbo)> Fortunella classifolia(Rong’an). Above all, Fortunella obovata (Wenguangju) and Fortunella japonica(Ningbo) had high comprehensive quality and nutritional value. The result could provide new varieties choice for citrus industry development in Chongqing. Figures and Tables | References | Related Articles | Metrics

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Rapid determination of mineral elements in broccoli by near-infrared spectroscopy LEI Yumeng, YAN Guochao, YANG Jing, ZHU Zhujun 2022, 34(3):  548-556.  DOI: 10.3969/j.issn.1004-1524.2022.03.15 Abstract ( 1133 )   HTML ( 425 )   PDF (1441KB) ( 763 )   Broccoli is a cruciferous vegetable with high content of mineral elements. The traditional determination method was cumbersome, time-consuming and laborious. In this study, contents of mineral elements including potassium, sulfur, phosphorus, calcium, ferrum and magnesium in broccoli were determined by inductively coupled plasma atomic emission spectrometry (ICP-OES). At the same time, the samples were scanned by near-infrared spectrometer, and spectral files of samples were obtained. The near-infrared spectral method for rapid determination of mineral elements in broccoli was proposed. On the basis of partial least square (PLS) analysis, chemical analysis results and spectral files were smoothed by Savitzky-Golay convolution. Multivariate scattering correction (MSC) and standard normal variable (SNV) with different scattering processing methods, and the first derivative (FD) and second derivative (SD) of derivative processing methods were used to pretreat the spectra to obtain the calibration equation. The results showed that: (1) K, Mg and Ca had the best results after MSC+FD treatment, coefficient of determination in calibration (RSQ) was 0.884, 0.944 and 0.651, respectively, and coefficient of determination in valibration (R2) was 0.893, 0.928 and 0.604, respectively. Residual predictive deviation (RPD) values were 2.491, 2.710 and 1.344, respectively; (2) P had the best effect after SNV+FD treatment, RSQ, R2 and RPD values were 0.733, 0.703 and 1.117, respectively; (3) S and Fe had the best result after MSC+SD treatment, RSQ were 0.523, 0.581, R2 were 0.537 and 0.416, respectively, and RPD were 1.133 and 1.100, respectively. The established model for rapid detection of K and Mg in near infrared spectroscopy could be used for practical applications. P could be predicted approximately quantitatively, but the accuracy and stability of the model needed to be improved by increasing samples types; Prediction degree of the near infrared models of Ca, S and Fe could be improved by establishing two models of high concentration and low concentration. Figures and Tables | References | Related Articles | Metrics

Plant Protection

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Acute toxicity of cyflumetofen and its metabolites to Daphnia magna Straus AN Xuehua, LI Dongxue, DAI Demao, YU Shifeng, ZHAO Meiqin, WU Shenggan, ZHAO Xueping 2022, 34(3):  557-565.  DOI: 10.3969/j.issn.1004-1524.2022.03.16 Abstract ( 489 )   HTML ( 287 )   PDF (856KB) ( 624 )   To evaluate the risk of cyflumetofen and its metabolites on aquatic organisms, acute toxicities of cyflumetofen and its metabolites [A-2, AB-1 dimer, AB-1, AB-11, B-1, B-3, Target 1(B-2), Met-1] on Daphnia magna Straus within 48 h were carried out by semi-static tests, and chronic toxicities of cyflumetofen on D. magna were also investigated by 21 d exposure tests. It was shown that the 48h-EC50 (50% inhibitory concentration) of cyflumetofen, Target 1 (B-2) and Met-1 on D. magna were>0.011 5, >0.031 5,>0.032 8 mg·L-1, respectively, indicating that these reagents had no effect on the activity of D. magna in the concentration range of solubility. The 48 h-EC50 of B-1 and B-3 were both higher than 133 mg·L-1, indicating low toxicity. The 48 h-EC50 of A-2, AB-1 dimer, AB-1 and AB-11 were 7.20, 0.000 127, 1.71, 0.316 mg·L-1, respectively, indicating medium toxicity, very high toxicity, medium toxicity and high toxicity.The no observable effect concentration (NOEC) of D. magna continuously exposed for 21 d was less than 0.017 8 mg·L-1, indicating that the cyflumetofen had no significant inhibitory effect on the growth and reproduction of D. magna in the maximum solubility.Based on 48 h-EC10 (10% inhibitory concentration) and 48 h-EC50, the acute-chronic toxicity ratio (ACR) was calculated.The determined ACRs of A-2, AB-1 dimer, AB-1 and AB-11 ranged from 0.235 to 1.60, which were much lower than the recommended values (100). In conclusion, cyflumetofen within the maximum solubility had no acute and chronic toxic effects on D. magna, but its metabolites A-2, AB-1 dimer, AB-1 and AB-11 had adverse effects,of which the environmental risk should never be neglected.The present results provided scientific basis for the assessment of aquatic environment risk and safe use of cyflumetofen. Figures and Tables | References | Related Articles | Metrics

Environmental Science

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Optimization of drip fertigation scheme for Coffea arabica based on soil quality index SUN Wenyan, LIU Xiaogang, ZHANG Wenhui, LI Huiyong, WU Lang, YANG Qiliang, XIONG Guomei 2022, 34(3):  566-573.  DOI: 10.3969/j.issn.1004-1524.2022.03.17 Abstract ( 425 )   HTML ( 207 )   PDF (867KB) ( 894 )   In the present study, a full combination test with 2 factors (fertilization level and irrigation level) of 3 levels was carried out. Three fertilization levels (based on single plant) were set as FH 190.8 g, FM 127.2 g, FL 63.6 g, and three irrigation levels (based on single plant) were set as WH 190.63 L, WM 158.86 L, WL 132.90 L. Based on the contents of soil nitrate nitrogen, available phosphorus, available potassium, number of bacteria, fungi and actinomycetes, and activities of catalase, phosphatase and urease, soil quality index (SQI) was constructed. Based on SQI in the root zone of Coffea arabica under different treatments, the suitable drip fertigation scheme was screened out. It was shown that the increasing irrigation level could decrease soil nutrients contents, yet soil nutrients contents increased with the increasing fertilization level. Among all the treatments, soil nutrients contents under FHWL was the highest, and its nitrate nitrogen, available phosphorus, available potassium contents were significantly (P<0.05) increased by 185.7%, 422.9%, 95.9%, respectively, than those of FLWL. The microbial (including bacteria, fungi and actinomycetes) quantity and soil enzymes activities increased with the elevated irrigation level, yet increased first and decreased later with the elevated fertilization level. Compared with FLWL, FMWH showed the best performance in increasing microbial quantity and improving soil enzymes activities, as the number of bacteria, fungi, actinomycetes, and activities of catalase, phosphatase, urease were significantly (P<0.05) increased by 176.4%, 73.3%, 49.2%, 45.1%, 24.6%, 146.6%, respectively. The highest SQI was recorded under FMWH. Therefore, the most suitable drip fertigation scheme was high irrigation level coupled with medium fertilization level (FMWH) under experiment conditions. Figures and Tables | References | Related Articles | Metrics

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Production of bacterial manure via fermentation of meat and bone meals of sick animals by Bacillus natto NT-6 TANG Xiaoshan, HOU Xiaoqin, SUN Lijun, FANG Zhijia, DENG Qi 2022, 34(3):  574-581.  DOI: 10.3969/j.issn.1004-1524.2022.03.18 Abstract ( 334 )   HTML ( 201 )   PDF (5206KB) ( 782 )   In the present study, meat and bone meals were used as fermentation substrate, Bacillus natto NT-6 was used as fermentation and function bacteria, and bacterial manure was produced by soil fermentation.With NT-6 quantity as the main index, the fermentation conditions were optimized by single factor tests and response surface design. On the basis, the effect of the produced bacterial manure against pathogen of the tomato stem rot (Rhizoctonia solani Kühn) were explored. It was shown that the optimal fermentation condition were as follows: the ratio of meat bone to bran was 7.8:2.2, the moisture content was 58.19%, the addition amount of rice husks was 0.82 g, the fermentation time was 100 h. Under this condition, the NT-6 quantity in fermentation product was the highest (2.92×1010 CFU·g-1). The produced bacterial manure had no significant promotion effect on seed germination, yet increased biomass of tomato. In soils infected by R. solani, the mortality rate of tomato was 55%, yet it decreased to 20% with application of the produced bacteria manure. In general, meat and bone meals could be used to produce bacteria manure via solid fermentation by B. natto NT-6. The produced bacterial manure not only could enhance the growth of tomato, but also could increase resistance to R. solani. Figures and Tables | References | Related Articles | Metrics

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Hyperspectral characteristics and leaf area index (LAI) and SPAD value inversion of winter wheat under elevated CO2 concentration CAI Yao, MIAO Yuxuan, WU Hao, WANG Dan 2022, 34(3):  582-589.  DOI: 10.3969/j.issn.1004-1524.2022.03.19 Abstract ( 508 )   HTML ( 507 )   PDF (1168KB) ( 846 )   In the present study, winter wheat was selected as the research object, and an open-top chamber experiment was carried out with ambient CO2 as control (CK) and plus 200 μmol·mol-1CO2 on the basis of CK as treatment (T). The canopy spectral reflectance, leaf area index(LAI) and SPAD value of winter wheat at main growth stages were measured. The correlation within LAI, SPAD value, original spectral reflectance and spectral characteristic parameters were analyzed, and the optimal estimation models were established. The results showed that the elevated CO2 concentration increased LAI and SPAD value of winter wheat at booting-heading stage and filling stage.The elevated CO2 concentration did not change the spectral reflectance curve, but changed the reflectance. The elevated CO2 concentration induced the red edge position red shift first and then blue shift.Red and yellow edge area ratio (x) was the most suitable spectral parameter to estimate LAI(y) of wheat, and the regression equation was y=3.96×10-3x2-8.60×10-2x+1.93, of which the coefficient of determination (R2) and the root mean square error (RMSE) on validation set were 0.66 and 0.42, respectively. Red edge amplitude (x) was the most suitable spectral parameter to estimate SPAD value (y) of wheat, and the regression equation was y=-5.151×104x2+2.883×103x+33.83, of which the R2 and RMSE on validation set were 0.63 and 4.61, respectively. Figures and Tables | References | Related Articles | Metrics

Biosystems Engineening

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Wheat variety recognition method based on same position segmentation of transmitted light and reflected light images YAN Ning, ZHANG Han, DONG Hongtu, KANG Kai, LUO Bin 2022, 34(3):  590-598.  DOI: 10.3969/j.issn.1004-1524.2022.03.20 Abstract ( 526 )   HTML ( 251 )   PDF (1685KB) ( 784 )   A segmentation method of embryo and endosperm image based on transmitted light and reflected light at the same position of wheat seeds was proposed in order to improve the recognition accuracy of wheat varieties. In this paper, according to the characteristics of great difference in transmissibility between embryo and endosperm of wheat seed, color feature information was extracted from reflected light images and transmitted light images for modeling and analysis, the influence of transmission light characteristics and color characteristics of seed embryo and endosperm on wheat seed variety recognition were studied. Taking the four varieties of seeds of Jimai 22, Jimai 44, Jingmai 9, and Jingmai 11 as the materials, the color characteristic parameters of the seeds were obtained by using the HALCON machine vision software, and through partial least squares discriminant analysis (PLS-DA) method to establish a classification model. The results showed that after the transmission light image was used to assist the reflected light image segmentation, more seed color parameter information was fused, so that the accuracy of the four varieties of wheat seed recognition was improved. The correct rate of hybrid recognition between Jimai and Jingmai had increased from 95% of the color characteristics of seed reflected light to more than 99% of the color characteristics of transmitted light, embryo and endosperm. The hybrid recognition accuracy rate of Jimai 22 and Jimai 44 increased from 73.28% to 84.60%, and the hybrid recognition accuracy rate of Jingmai 9 and Jingmai 11 increased from 74.15% to 83.73%. The further fusion analysis of the color features contained in the image of seed embryo and endosperm through the transmitted light features can effectively improve the accuracy of wheat variety recognition. Figures and Tables | References | Related Articles | Metrics

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Experimental study on vibration response and fruit dropping of chestnut tree HAN Yuanshun, XU Linyun, ZHOU Jie, YU Bing 2022, 34(3):  599-613.  DOI: 10.3969/j.issn.1004-1524.2022.03.21 Abstract ( 435 )   HTML ( 549 )   PDF (4995KB) ( 630 )   In order to solve the problem of low efficiency and high cost of artificial harvesting of chestnut, parameter support was provided for the design of mechanical vibration harvesting equipment of chestnut. For three chestnut trees, the acceleration response and fruit dropping on each branch of chestnut tree were studied by single eccentric vibration motor. The results indicated that the combined acceleration at the measured points of the trunk and branches of the three trees showed a quadratic curve growth relation with the excitation frequency, and the increase of excitation frequency was conducive to the enhancement of the vibration response of each branch of chestnut tree. However, due to the change of the distance from the excitation point and the diameter of the fruit branch, the vibration of each branch under the excitation of external force was often distributed unevenly, resulting in a certain difference in acceleration response characteristics in X, Y and Z directions at each measurement point. With the increase of excitation frequency, the dropping rate of chestnut ripening fruits and immature fruits also gradually increased. Through the analysis of comprehensive scoring method, it was concluded that under the excitation frequency of 18-22 Hz, the dropping rate of three trees was relatively ideal, which could achieve the purpose of selective harvesting. Figures and Tables | References | Related Articles | Metrics

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Parameter optimization experiment of seedling guiding tube transplanting machine of Panax notoginseng seedling QIN Wei, YU Yingjie, LAI Qinghui, ZHAN Caixue, YUAN Haikuo, ZHANG Haijun 2022, 34(3):  614-625.  DOI: 10.3969/j.issn.1004-1524.2022.03.22 Abstract ( 403 )   HTML ( 7191 )   PDF (10205KB) ( 668 )   In order to realize the directional transplanting of Panax notoginseng seedlings, a seedling guiding tube transplanting machine of P. notoginseng seedlings was designed. The directional process and the mechanism of the seedling guiding process during the operation of the seedling guiding tube transplanting machine of P. notoginseng seedlings were analyzed, and the main factors affecting the planting of seedlings were determined. The single-factor simulation test of the directional process was carried out by using EDEM software, the directional platform was built according to the simulation test results, the orthogonal test of the directional performance of the directional mechanism was carried out, and the better parameter working combination of the directional mechanism was determined. The operating speed of the unit, the rotation speed of the directional plate and the inclination angle of the seedling guide tube were selected as the experimental factors, the orthogonal rotation combined test with three factors and five level was carried out and a mathematical model of the qualified rate of planting spacing and replanting rate were established, and the influence of the interaction of various experimental factors on the qualified rate of plant spacing and replanting rate was analyzed. The optimal combination of parameters of the transplanting machine obtained by response surface method of central composite. The results showed that when the inclination angle of the seedling guide tube was fixed at 74.32°, the bench forward speed of the unit was 0.95-1.11 km·h-1, the rotation speed of the directional plate was 24.32-27.57 r·min-1, the qualified rate of the plant spacing was more than 90%, and the replanting rate was less than 5%. In order to verify the reliability of the optimization results, the verification test of the performance of the transplanting machine was carried out, the bench forward speed of the unit was 1 km·h-1, the rotation speed of the directional plate was 25 r·min-1, and the inclination angle of the seedling guide tube was 75°. At this time, the qualified rate of plant spacing was 90.6%, the replanting rate was 4.2%. The results were in accordance with the national standard, meeting the agronomic requirements of P. notoginseng seedling transplanting. Figures and Tables | References | Related Articles | Metrics

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Design and experiment of energy-saving lighting system for plant factory based on OpenCV LIN Xiaoteng, SUN Qian, ZHENG Shuhe 2022, 34(3):  626-635.  DOI: 10.3969/j.issn.1004-1524.2022.03.23 Abstract ( 449 )   HTML ( 12316 )   PDF (5071KB) ( 707 )   In order to solve the problem of high energy consumption of light system in the plant factory, the energy-saving lighting system was designed based on OpenCV vision library. In the proposed system, the light source was optically redesigned to make the divergent LED light into a circular spot. Thus, it could provide sufficient light for plants with a smaller power, and reduce energy consumption in the areas without plant. The mechanical structure and control system were also designed. The image recognition algorithm was designed to identify dynamic change of the spot size with the growth of plant based on the OpenCV vision library of Raspberry Pi, which could improve the automation of this system. A test on the effect of the proposed system was carried out with butter lettuce as the plant material, and the ordinary lighting system as the control. The results showed that the energy consumption of the proposed system was reduced by 55.8%, and its power utilization efficiency was increased by 72.7%. In general, the proposed system had energy-saving effect and realized higher power utilization efficiency. Figures and Tables | References | Related Articles | Metrics

Agricultural Economy and Development

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Can poverty alleviation through agricultural e-commerce improve smallholder’s sustainable livelihood?: from perspective of agricultural product sales WANG Cuicui, XIA Chunping, CAI Yi 2022, 34(3):  636-651.  DOI: 10.3969/j.issn.1004-1524.2022.03.24 Abstract ( 493 )   HTML ( 22612 )   PDF (1734KB) ( 657 )   In the present study, an evaluation system of smallholder’s sustainable livelihood was constructed from 3 aspects (development capacity, economic capacity and social capacity), 16 indicators, and was used to evaluate the performance of poverty alleviation through agricultural e-commerce. The weights of indicators in the constructed system were determined via combination weighting approach. Based on relative references and survey data of 252 smallholders (including both out-of-poor smallholders and poor smallholders) in Hubei Province, China, the sustainable livelihood of all samples was measured. The influencing factors on smallholder’s sustainable livelihood during poverty-alleviation through agricultural e-commerce were explored via 5 regression methods, including OLS, 2SLS, LIML, IVGMM and IV-Tobit, and the relationship and hierarchical structure of these influencing factors were revealed by ISM model. It was found that the sustainable livelihood of samples was general, with relatively higher development capacity and economic capacity and relatively lower social capacity. But, all these capacities were in need of improvement. Whether to participate in agricultural e-commerce, whether there are village cadres among relatives, public service, government support and industrial base had significant (P<0.1) impact on smallholder’s sustainable livelihood. Among them, whether to participate in agricultural e-commerce and whether there are village cadres among relatives were the surface direct influencing factors, government support and industrial base were the indirect influencing factors, and the public service was the bottom factor. The logical hierarchy of these factors could be summarized as “single drive, double path”. Figures and Tables | References | Related Articles | Metrics

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Research on training behavior of high quality farmers from perspective of social capital demand: based on theory of planned behavior HUANG Hexiao, ZHANG Xihua, ZHUO Ni, LI Baozhi, ZHANG Weijiang, ZHU Qibiao 2022, 34(3):  652-660.  DOI: 10.3969/j.issn.1004-1524.2022.03.25 Abstract ( 638 )   HTML ( 6195 )   PDF (859KB) ( 704 )   Talent is a key factor to support the Rural Revitalization Strategy. The cultivation of high quality farmers has been promoted to a new height in the new era. Based on the theory of planned behavior (TPB), this paper conducted an empirical analysis with structural equation model (SEM) and 760 effective samples to explore the influencing factors of high quality farmers’ training behavior from the perspective of social capital demand. The results showed that the attitude toward behavior of high quality farmers with social capital demand had significantly (P<0.01) positive impact on their behavior intention. And high quality farmers’ behavior intention had significantly (P<0.01) positive impact on their actual behavior. Therefore, the training of high quality farmers should focus on actual needs, establish communication platforms, strengthen tracking services, build training brands, accurately pinpoint training objects and optimize training programs, break the limitation of time and space and activate training forms. Figures and Tables | References | Related Articles | Metrics