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Determination of 24 common pesticides in water samples by automatic online HS-SPME-GC/MS
YU Jiabin, ZOU Bo, WEI Chunming, etc
Abstract： In order to improve the efficiency and sensitivity of trace pesticide detection in environmental water, an automatic online headspace solid phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC/MS) was established for the detection of twenty-four common pesticides in water. The effects of extraction needle coating material, extraction temperature, extraction time and desorption time on the extraction efficiency were investigated, and the ion concentration in solid phase microextraction matrix was optimized. The results showed that the concentration-response linear relationship of 24 target pesticides was good, and the determination coefficients (R2) were all greater than 0.9950. The limits of detection (LOD) was 0.25-5.0 μg/L, and the limits of quantification (LOQ) was 0.5-10 μg/L. The recoveries were 86%-117% and the relative standard deviation (RSD) was less than 18%. This method is suitable for the rapid qualitative and quantitative determination of trace organophosphorus, carbamate, organochlorine and permethrin pesticides in water samples, and it has the advantages of convenience, high efficiency and high sensitivity. It could be used for the inspection and identification of material evidence in pesticide poisoning cases in environmental water. [Review Details]
Ecological risk assessment of imidacloprid in surface water from rice- vegetable rotation areas by using interspecies correlation estimation
TAN Huadong, WANG Chuanmi, WU Qiumin, etc
Abstract： Imidacloprid is widely detected in surface water from sub-tropical or tropical agricultural regions of China. However, there is scanty information on the ecological risk assessment of imidacloprid in surface water near tropical crop systems due to the lack of toxicity data on local aquatic organisms. In this study, the acute toxicity risk threshold-hazardous concentration at the 5th percentile of the species (HC5) -of imidacloprid to local aquatic organisms in surface water was obtained based on web-interspecific correlation estimation (Web-ICE) and species sensitivity distribution (SSD) models, then its ecological risk assessment in surface water near rice-vegetable practice in Chengmai (Hainan) was temporally and spatially assessed by risk quotient (RQ). The results showed that the risk threshold HC5 of imidacloprid in the aquatic environment around the rice-vegetable rotation in Chengmai is 4.30 μg/L, 41.7% of water samples with the RQ of higher than 1. Also, the RQ values corresponding to the median and maximum concentrations of imidacloprid in surface water from our study were significantly higher than the RQ values in surface water from other regions of China, indicating that imidacloprid residues had higher potential ecological risks to aquatic organisms in surface water from tropical rice-vegetable rotation field. In addition, there was the highest potential ecological risk occurring in April, the sowing time (RQ>1 in 92.3% surface water), vegetable planting period (mean RQ=2.53 with RQ>1 with 68% water surface water), and the central regions of Chengmai during the practice of rice-vegetable rotation, indicating that there were significant spatiotemporal and crop-related characteristics of the ecological risk of imidacloprid in surface water. It thus contrives to limit and reasonably use imidacloprid by planting period and region in the practice of rice-vegetable rotation in Chengmai, Hainan. [Review Details]
Effects of Bordeaux mixture on the community structure and metabolic function of tobacco phyllosphere microorganisms
LIU Tingting, WANG Hancheng, SUN Meili, etc
Abstract： In this paper, the virulence of Bordeaux mixture against Alternaria alternata was determined, and the effects of Bordeaux mixture on phyllosphere microbial community structure and metabolic function of healthy and diseased tobacco leaves were determined by high-throughput sequencing and Biolog metabolic phenotype technology. Results showed that Bordeaux mixture had a weak inhibitory activity against A. alternata with EC50 values for inhibiting mycelial growth and spore germination of 450.19 and 757.17 mg/L, respectively. The phyllosphere bacteria in both healthy and diseased tobacco were distributed in Proteobacteria (6.93% and 39.07%) and Firmicutes (16.45% and 0.65%), and the dominant bacterial genera were Kosakonia (3.46% and 22.38%) and Pseudomonas (0.22% and 5.95%). The phyllosphere fungi in both healthy and diseased tobacco were distributed in Ascomycota (63.82% and 93.74%) and Basidiomycota (6.82% and 2.53%), and the dominant fungal genera were Alternaria (36.48% and 84.52%), Symmetrospora (5.56% and 2.27%) and Cladosporium (14.87% and 6.66%). Bordeaux mixture at 1 500 g/hm2 affected the community structure and metabolic function of phyllosphere bacteria and fungi in healthy and diseased tobacco. In the bacterial and fungal communities, the relative abundances of Kosakonia, Sphinomonas, and Lactobacillus decreased, while the relative abundances of 6 bacterial genera including Pseudomonas, Ralstonia increased after 5 days of treatment. The relative abundance of 6 fungal genera including Alternaria, Symmetrospora decreased, while the relative abundance of 10 fungal genera including Didymella, Metarhizium increased after 5 days of treatment. The effects of Bordeaux mixture on phyllosphere fungi and bacteria gradually decreased after 10 and 15 days of treatment. Twenty-nine carbon sources including carbohydrates, amino acids, carboxylic acids, amphiphiles, polymers, and amine/amino compounds could be efficiently metabolized by phyllosphere microorganisms of healthy and diseased tobacco leaves, but the metabolism of α-butyric acid was weak. The metabolic inhibition activity of Bordeaux mixture on phyllosphere microorganisms decreased gradually with the increase of time. The results of the study revealed the regularity of the effect of Bordeaux mixture on the microbes of tobacco leaves after different periods of application and provided a reference for understanding the ecological benefits of the fungicide in the effective period. [Review Details]
Breeding of high-yield strains for producing ethyl ivermectin and the optimization of the fermentation process
LI Bing, QI Huan, ZHANG Chenghong, etc
Abstract： Methyl ivermectin and ethyl ivermectin, as a new kind of avermectin derivatives with high efficacy and low toxicity, were obtained from a genetically engineered strain Streptomyces avermitilis AVE-H39 and have a good prospect of development and application. Bioassay results showed that the insecticidal activity of ethyl ivermectin against the agricultural and forestry pests including Tetranychus cinnabarinus and Bursaphelenchus xylophilus was higher than that of methyl ivermectin. However, the industrial development of ethyl ivermectin is restricted by its low fermentation titer. In this research, a mutant strain with a higher fermentation yield of ethyl ivermectin was obtained through multiple rounds of mutagenesis and breeding. The fermentation medium was improved by Plackett-Burman experimental design and Box-Behnken design-response surface methodology (RSM). The optimized fermentation condition was corn starch 149.8 g/L, soybean flour 38.1 g/L, (NH4)2SO4 3.04 g/L, mannitol 30.0 g/L, yeast extract 20.0 g/L, CaCO3 3.0 g/L, CoCl2 0.01 mg/L, FeSO4 0.002 mg/L, rotation speed 220 r/min, initial pH 7.2, 30 mL medium per 250 mL Erlenmeyer flasks, inoculum volume 5%, fermentation temperature 28 ℃. Under the optimized condition, the fermentation titer of ethyl ivermectin reached the maximum value of 4965 mg/L. This research lay the foundation for the development of the new sixteen-membered macrolide insecticide ethyl ivermectin. [Review Details]
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, Available online ,
doi: 10.16801/j.issn.1008-7303.2022.0133
Abstract:
In order to establish a rapid screening method for chlorothalonil residues in blueberry samples, the pesticide chlorothalonil was used as the target analyte in this study, and the effects of colloidal gold labeling parameters and sample preparation methods on colloidal gold immuno-chromatographic assay (GICA) were systematically studied. Firstly, 25 nm colloidal gold nanoparticles labelled with anti-chlorothalonil monoclonal antibody was used as the detection probe. Chlorothalonil-BSA (1 mg/mL) conjugate and goat anti-mouse IgG antibody (0.1 mg/mL) were coated on nitrocellulose filter membrane (NC) to form the test line (T) and quality control line (C), respectively. Then the blueberry samples were extracted with acidic acetonitrile and diluted with double distilled water (dd H2O), and were detected by the assembled immuno-chromatographic test strip. The qualitative and semi-quantitative analysis of chlorothalonil in blueberries could be accomplished within 15 minutes, and the limit of detection (LOD) observed by naked eyes was 0.1 mg/kg. The cross-reactivity for the detection of 4-hydroxy-chlorothalonil, quintozene, carbendazim and procymidone was negligible. The recovery results of chlorothalonil in blueberry using the colloidal gold immuno-chromatographic test strip were consistent with those of the UPLC-MS/MS method. Both methods could be successfully applied to the detection of chlorothalonil in blueberries. The immuno-chromatographic test strip is helpful for on-site detection, while the UPLC-MS /MS method can provide accurate quantification.
In order to establish a rapid screening method for chlorothalonil residues in blueberry samples, the pesticide chlorothalonil was used as the target analyte in this study, and the effects of colloidal gold labeling parameters and sample preparation methods on colloidal gold immuno-chromatographic assay (GICA) were systematically studied. Firstly, 25 nm colloidal gold nanoparticles labelled with anti-chlorothalonil monoclonal antibody was used as the detection probe. Chlorothalonil-BSA (1 mg/mL) conjugate and goat anti-mouse IgG antibody (0.1 mg/mL) were coated on nitrocellulose filter membrane (NC) to form the test line (T) and quality control line (C), respectively. Then the blueberry samples were extracted with acidic acetonitrile and diluted with double distilled water (dd H2O), and were detected by the assembled immuno-chromatographic test strip. The qualitative and semi-quantitative analysis of chlorothalonil in blueberries could be accomplished within 15 minutes, and the limit of detection (LOD) observed by naked eyes was 0.1 mg/kg. The cross-reactivity for the detection of 4-hydroxy-chlorothalonil, quintozene, carbendazim and procymidone was negligible. The recovery results of chlorothalonil in blueberry using the colloidal gold immuno-chromatographic test strip were consistent with those of the UPLC-MS/MS method. Both methods could be successfully applied to the detection of chlorothalonil in blueberries. The immuno-chromatographic test strip is helpful for on-site detection, while the UPLC-MS /MS method can provide accurate quantification.
, Available online ,
doi: 10.16801/j.issn.1008-7303.2023.0011
Abstract:
In this work, an endophytic bacterial strain ST6 with chlorpyrifos-degrading ability was isolated from chlorpyrifos-contaminated rice (Oryza sativa L.) and identified as Aeromonas hydrophila by 16S rRNA analysis. The strain ST6-gfp was successfully colonized in rice plants after being labeled with the green fluorescent protein gene (gfp), and the colony number of ST6-gfp in rice roots was 6.98-7.26 log CFU/g, and that in stems and leaves was 4.88-5.14 log CFU/g by plate recovery tests. The effect and the mechanisms of the endophytic bacteria colonization on the degradation of chlorpyrifos was investigated with pot experiments. The results show that the interaction between the plant and the endophytic bacteria promotes the degradation of chlorpyrifos and the growth of rice, and the content of chlorpyrifos in ST6-gfp inoculated rice is 41.7% lower than that in the uninoculated rice. The plant height, fresh weight and chlorophyll content of the inoculated rice increase by 38.9%, 69.5%, and 41.6%, respectively, compared with the uninoculated control. Under chlorpyrifos stress, ST6-gfp colonization enhancs the activity of oxidoreductase and detoxification enzymes in rice, in which the activities of superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase(APX), glutathione reductase (GR) and catalase (CAT) were increased by 1.1, 1.3, 1.2, 1.8, and 1.2 fold, respectively; the activities of cytochrome P450 (CYP450) and glutathione S-transferase (GST) were up-regulated by 1.5-1.7 fold. In addition, the MDA content of inoculated rice was reduced by 46.9% compared with that of uninoculated rice. This study suggests that ST6 colonization accelerates the degradation of chlorpyrifos in rice by increasing the activities of antioxidant and detoxification enzymes, thus reducing the stress damage caused by chlorpyrifos and improving the tolerance of rice to chlorpyrifos.
In this work, an endophytic bacterial strain ST6 with chlorpyrifos-degrading ability was isolated from chlorpyrifos-contaminated rice (Oryza sativa L.) and identified as Aeromonas hydrophila by 16S rRNA analysis. The strain ST6-gfp was successfully colonized in rice plants after being labeled with the green fluorescent protein gene (gfp), and the colony number of ST6-gfp in rice roots was 6.98-7.26 log CFU/g, and that in stems and leaves was 4.88-5.14 log CFU/g by plate recovery tests. The effect and the mechanisms of the endophytic bacteria colonization on the degradation of chlorpyrifos was investigated with pot experiments. The results show that the interaction between the plant and the endophytic bacteria promotes the degradation of chlorpyrifos and the growth of rice, and the content of chlorpyrifos in ST6-gfp inoculated rice is 41.7% lower than that in the uninoculated rice. The plant height, fresh weight and chlorophyll content of the inoculated rice increase by 38.9%, 69.5%, and 41.6%, respectively, compared with the uninoculated control. Under chlorpyrifos stress, ST6-gfp colonization enhancs the activity of oxidoreductase and detoxification enzymes in rice, in which the activities of superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase(APX), glutathione reductase (GR) and catalase (CAT) were increased by 1.1, 1.3, 1.2, 1.8, and 1.2 fold, respectively; the activities of cytochrome P450 (CYP450) and glutathione S-transferase (GST) were up-regulated by 1.5-1.7 fold. In addition, the MDA content of inoculated rice was reduced by 46.9% compared with that of uninoculated rice. This study suggests that ST6 colonization accelerates the degradation of chlorpyrifos in rice by increasing the activities of antioxidant and detoxification enzymes, thus reducing the stress damage caused by chlorpyrifos and improving the tolerance of rice to chlorpyrifos.
, Available online ,
doi: 10.16801/j.issn.1008-7303.2022.0144
Abstract:
In order to investigate the pesticide residue levels in pak-choi in the main producing areas of Fujian Province, and to assess the dietary exposure risks to human body, 88 pak-choi samples were collected and detected using the standard residue analytical method of 68 pesticides in vegetables, and the short-term and long-term dietary exposure risks were assessed. The results showed that 27 pesticides were detected in 88 samples, including 18 insecticides and 9 fungicides, and the detection rate was 77.27%. The samples with 2 or more detected pesticides accounted for 83.82% of the total samples with detected pesticide residues, which means that the multiple pesticide residues occurred. Using the pesticide toxicology data, acceptable daily intake (ADI), acute reference dose(ARfD), residue data, and pak-choi consumption data, the risk assessment of detected pesticides showed that the short-term dietary exposure risk (%ARfD) ranged from 0 to 90%, and the contribution rate of the long-term dietary exposure risk (RQc%) ranged from 0 to 46%. The results showed that residue levels of detected pesticides in pak-choi were low, and the dietary exposure risk was acceptable for customers to consume pak-choi produced in Fujian Province.
In order to investigate the pesticide residue levels in pak-choi in the main producing areas of Fujian Province, and to assess the dietary exposure risks to human body, 88 pak-choi samples were collected and detected using the standard residue analytical method of 68 pesticides in vegetables, and the short-term and long-term dietary exposure risks were assessed. The results showed that 27 pesticides were detected in 88 samples, including 18 insecticides and 9 fungicides, and the detection rate was 77.27%. The samples with 2 or more detected pesticides accounted for 83.82% of the total samples with detected pesticide residues, which means that the multiple pesticide residues occurred. Using the pesticide toxicology data, acceptable daily intake (ADI), acute reference dose(ARfD), residue data, and pak-choi consumption data, the risk assessment of detected pesticides showed that the short-term dietary exposure risk (%ARfD) ranged from 0 to 90%, and the contribution rate of the long-term dietary exposure risk (RQc%) ranged from 0 to 46%. The results showed that residue levels of detected pesticides in pak-choi were low, and the dietary exposure risk was acceptable for customers to consume pak-choi produced in Fujian Province.
, Available online ,
doi: 10.16801/j.issn.1008-7303.2023.0016
Abstract:
Maize ear rot is a serious fungal disease that occurs worldwide and Fusarium verticillioides is the predominant causal pathogen of maize ear rot in China. In order to determine the potential application of the C14α-demethylation inhibitor (DMI) against maize ear rot, the effects of metconazole on the mycelial growth, conidium production and germination, and germ tube elongation of 35 F. verticillioides strains collected from Shandong, Henan and Jiangsu provinces in China from 2019 to 2021 were determined by mycelial growth rate and spore germination method, respectively. Its effects on B-type fumonisins (FBs) production and the expression levels of FBs biosynthesis genes of F. verticillioides were determined. The mechanism of action was explored by measuring the production of ergosterol, glycerol and malondialdehyde (MDA), and mycelial conductivity of F. verticillioides after metconazole treatment. Meanwhile, metconazole was applied to the field to evaluate its control efficacy on maize ear rot. The results showed that metconazole had strong antifungal activity against 35 strains of F. verticillioides, and had a dose-dependent inhibitory effect on mycelial growth, conidium formation and germination, and germ tube elongation of F.verticillioides. The EC50 values of metconazole inhibiting mycelial growth of F.verticillioides ranged from 0.005 to 0.029 μg/mL, with an average EC50 value of (0.012 ± 0.006) μg/mL. The average inhibition rates of EC50 concentration of metconazole on conidial formation, germination and germ tube elongation of F. verticillioides were (20.59 ± 5.75)%, (24.88 ± 5.15)% and (59.98 ± 9.11)%, respectively. Metconazole significantly reduced the production of FBs and the expression level of FBs biosynthetic genes, and the inhibition rate on FBs production was 29.04%. The production of ergosterol in mycelia of F. verticillioides was significantly reduced, and the inhibition rate was 39.10%. At the same time, the production of glycerol and MDA, and relative conductivity were increased, and the induction rates of glycerol and MDA were 66.39% and 33.74%, respectively. Field experiments showed that the control effects of 90, 135 and 180 a.i./(g/hm2) metconazole against maize ear rot were (20.93 ± 4.65)%, (27.75 ± 5.71)% and (46.05 ± 9.90)%, and the yield increase rates were (8.86 ± 8.84)%, (17.28 ± 11.91)% and (33.20 ± 12.07)%, respectively, which were better than the control fungicide prothioconazole + tebuconazole. In summary, this study evaluated the potential of metconazole against maize ear rot and provided a theoretical basis for uncovering its antifungal activity and mechanism against F. verticillioides.
Maize ear rot is a serious fungal disease that occurs worldwide and Fusarium verticillioides is the predominant causal pathogen of maize ear rot in China. In order to determine the potential application of the C14α-demethylation inhibitor (DMI) against maize ear rot, the effects of metconazole on the mycelial growth, conidium production and germination, and germ tube elongation of 35 F. verticillioides strains collected from Shandong, Henan and Jiangsu provinces in China from 2019 to 2021 were determined by mycelial growth rate and spore germination method, respectively. Its effects on B-type fumonisins (FBs) production and the expression levels of FBs biosynthesis genes of F. verticillioides were determined. The mechanism of action was explored by measuring the production of ergosterol, glycerol and malondialdehyde (MDA), and mycelial conductivity of F. verticillioides after metconazole treatment. Meanwhile, metconazole was applied to the field to evaluate its control efficacy on maize ear rot. The results showed that metconazole had strong antifungal activity against 35 strains of F. verticillioides, and had a dose-dependent inhibitory effect on mycelial growth, conidium formation and germination, and germ tube elongation of F.verticillioides. The EC50 values of metconazole inhibiting mycelial growth of F.verticillioides ranged from 0.005 to 0.029 μg/mL, with an average EC50 value of (0.012 ± 0.006) μg/mL. The average inhibition rates of EC50 concentration of metconazole on conidial formation, germination and germ tube elongation of F. verticillioides were (20.59 ± 5.75)%, (24.88 ± 5.15)% and (59.98 ± 9.11)%, respectively. Metconazole significantly reduced the production of FBs and the expression level of FBs biosynthetic genes, and the inhibition rate on FBs production was 29.04%. The production of ergosterol in mycelia of F. verticillioides was significantly reduced, and the inhibition rate was 39.10%. At the same time, the production of glycerol and MDA, and relative conductivity were increased, and the induction rates of glycerol and MDA were 66.39% and 33.74%, respectively. Field experiments showed that the control effects of 90, 135 and 180 a.i./(g/hm2) metconazole against maize ear rot were (20.93 ± 4.65)%, (27.75 ± 5.71)% and (46.05 ± 9.90)%, and the yield increase rates were (8.86 ± 8.84)%, (17.28 ± 11.91)% and (33.20 ± 12.07)%, respectively, which were better than the control fungicide prothioconazole + tebuconazole. In summary, this study evaluated the potential of metconazole against maize ear rot and provided a theoretical basis for uncovering its antifungal activity and mechanism against F. verticillioides.
, Available online ,
doi: 10.16801/j.issn.1008-7303.2022.0139
Abstract:
Oxysterol-binding protein (OSBP) and its homologous proteins (ORPs) constitute a conserved family of lipid-binding/lipid transfer proteins (LTPs), which are widely expressed in eukaryotic cells. It participated lipid metabolism, vesicle transport and signal transduction in organisms. Here, the structure and function of OSBPs are described systematically, and the targeted inhibitors based on OSBPs are reviewed too. It provided theoretical support and practical models for the rational design and application of pesticide based on new targets.
Oxysterol-binding protein (OSBP) and its homologous proteins (ORPs) constitute a conserved family of lipid-binding/lipid transfer proteins (LTPs), which are widely expressed in eukaryotic cells. It participated lipid metabolism, vesicle transport and signal transduction in organisms. Here, the structure and function of OSBPs are described systematically, and the targeted inhibitors based on OSBPs are reviewed too. It provided theoretical support and practical models for the rational design and application of pesticide based on new targets.
, Available online ,
doi: 10.16801/j.issn.1008-7303.2023.0018
Abstract:
Difenoconazole is widely used and has been found to have excessive residues in edible agricultural products and has been detected in serum and follicular fluid of infertile women. To investigate the effects of subacute oral exposure to difenoconazole on ovarian function, we determined the changes of progesterone (P) and estradiol (E2) in rat serum after gavage administration of 50, 100, and 200 mg/(kg bw·d) of difenoconazole corn oil solution, and analyzed the number of follicles by light microscopy after hematoxylin-eosin (HE) staining of rat ovaries. The results showed that the ovarian organ coefficients of rats exposed to each dose group and the control group were not significantly different (P>0.05). Serum progesterone levels in rats exposed to 200 mg/(kg bw·d) were significantly higher than those in the control group (P<0.01), while those exposed to 50 and 100 mg/(kg bw·d) were not significantly different from the control group (P>0.05), but were significantly lower than those in the 200 mg/(kg bw·d) exposure group (P<0.05). There was no significant difference in serum estradiol (E2) levels between the exposed and control groups (P>0.05). In terms of follicle development, the percentage of growing follicles was significantly higher in the 200 mg/(kg bw·d) exposed group than in the control group (P<0.05), while there was no significant difference in the 50 and 100 mg/(kg bw∙d) exposed groups compared to the control group (P>0.05). The study showed that subacute oral exposure to 200 mg/(kg bw·d) of difenoconazole was toxic to rat ovaries and resulted in elevated serum progesterone levels and the proportion of growing follicles in rats at this exposure dose.
Difenoconazole is widely used and has been found to have excessive residues in edible agricultural products and has been detected in serum and follicular fluid of infertile women. To investigate the effects of subacute oral exposure to difenoconazole on ovarian function, we determined the changes of progesterone (P) and estradiol (E2) in rat serum after gavage administration of 50, 100, and 200 mg/(kg bw·d) of difenoconazole corn oil solution, and analyzed the number of follicles by light microscopy after hematoxylin-eosin (HE) staining of rat ovaries. The results showed that the ovarian organ coefficients of rats exposed to each dose group and the control group were not significantly different (P>0.05). Serum progesterone levels in rats exposed to 200 mg/(kg bw·d) were significantly higher than those in the control group (P<0.01), while those exposed to 50 and 100 mg/(kg bw·d) were not significantly different from the control group (P>0.05), but were significantly lower than those in the 200 mg/(kg bw·d) exposure group (P<0.05). There was no significant difference in serum estradiol (E2) levels between the exposed and control groups (P>0.05). In terms of follicle development, the percentage of growing follicles was significantly higher in the 200 mg/(kg bw·d) exposed group than in the control group (P<0.05), while there was no significant difference in the 50 and 100 mg/(kg bw∙d) exposed groups compared to the control group (P>0.05). The study showed that subacute oral exposure to 200 mg/(kg bw·d) of difenoconazole was toxic to rat ovaries and resulted in elevated serum progesterone levels and the proportion of growing follicles in rats at this exposure dose.
, Available online ,
doi: 10.16801/j.issn.1008-7303.2023.0014
Abstract:
The original deposition behavior of pesticides on leafy vegetables is an important index to evaluate pesticide residues, which is affected by crop morphology, pesticide and formulation type, application method and so on. Taking imidacloprid and acetamiprid as the target pesticides and spinach and lettuce as the target crops, the original deposition behavior of pesticides after application, as well as the effects of water content, leaf area index and pesticide formulation type on pesticide deposition were studied to reveal the original deposition law of pesticides on leafy vegetables. The results showed that there were no significant difference in the deposition amount of two pesticides within 0.5-8 h after application. In a comprehensive consideration, the original deposition amount was determined at 2 h after the application of the pesticides. The results showed that imidacloprid and acetamiprid were mainly deposited on the leaves of spinach and lettuce, accounting for more than 87% of total, and was much less in the root and soil. The original deposition amount of the two pesticides on spinach and lettuce had significant difference with different water dosages (at the same pesticide dosages). The original deposition amount of the two pesticides decreased gradually with the increase of water dosage. The deposition amount of two pesticides on spinach and lettuce were negatively correlated with leaf area index. The type of formulation of pesticides was also related to the original deposition amount. At the same pesticide dosage, imidacloprid in wettable powder had the highest original deposition in spinach and lettuce, with the deposition amounts of 0.66 and 0.77 mg/kg, respectively. While for acetamiprid, the highest original deposition amount in spinach and lettuce were occurred in emulsion formulation, with the deposition amount of 0.65 and 0.37 mg/kg, respectively, followed by wettable powder. The results indicated that the original deposition amount of pesticides on the surface of leafy vegetables was related to the types of pesticide formulation, water dosage and leaf area index. The finding could provide theoretical support for the rational and safe application of pesticides and the control of pesticide residues in leafy vegetables.
The original deposition behavior of pesticides on leafy vegetables is an important index to evaluate pesticide residues, which is affected by crop morphology, pesticide and formulation type, application method and so on. Taking imidacloprid and acetamiprid as the target pesticides and spinach and lettuce as the target crops, the original deposition behavior of pesticides after application, as well as the effects of water content, leaf area index and pesticide formulation type on pesticide deposition were studied to reveal the original deposition law of pesticides on leafy vegetables. The results showed that there were no significant difference in the deposition amount of two pesticides within 0.5-8 h after application. In a comprehensive consideration, the original deposition amount was determined at 2 h after the application of the pesticides. The results showed that imidacloprid and acetamiprid were mainly deposited on the leaves of spinach and lettuce, accounting for more than 87% of total, and was much less in the root and soil. The original deposition amount of the two pesticides on spinach and lettuce had significant difference with different water dosages (at the same pesticide dosages). The original deposition amount of the two pesticides decreased gradually with the increase of water dosage. The deposition amount of two pesticides on spinach and lettuce were negatively correlated with leaf area index. The type of formulation of pesticides was also related to the original deposition amount. At the same pesticide dosage, imidacloprid in wettable powder had the highest original deposition in spinach and lettuce, with the deposition amounts of 0.66 and 0.77 mg/kg, respectively. While for acetamiprid, the highest original deposition amount in spinach and lettuce were occurred in emulsion formulation, with the deposition amount of 0.65 and 0.37 mg/kg, respectively, followed by wettable powder. The results indicated that the original deposition amount of pesticides on the surface of leafy vegetables was related to the types of pesticide formulation, water dosage and leaf area index. The finding could provide theoretical support for the rational and safe application of pesticides and the control of pesticide residues in leafy vegetables.
, Available online ,
doi: 10.16801/j.issn.1008-7303.2022.0100
Abstract:
In order to find novel pesticide-active compounds, a series of new 2-(tralopyril-1-yl) ethyl carboxylic acid derivatives ( 5a-5m , 6a-6o ) were synthesized by nucleophilic substitution with tralopyril as the lead compound. Their structures were confirmed by 1H NMR, 13C NMR and HRMS. The results of fungicidal bioassay showed that compounds 2 , 3 and 5m exhibited good fungicidal activity against Magnaporthe oryzae with EC50 values of 0.0532, 0.0470 and 0.0174 mmol/L, respectively, which were better than the control agent fludioxonil (0.0914 mmol/L), but inferior to the control agent azoxystrobin (0.0001 mmol/L). Compound 5m showed a broad spectrum of fungicidal activity, and its EC50 values for the control of Rhizoctonia solani and Bipolaris sorokiniana were 0.0218 and 0.0420 mmol/L, respectively, but inferior to the control agent fludioxonil (EC50 values were 0.0002 and 0.0010 mmol/L, respectively). The bioassay results of insecticidal and acaricidal showed that at the concentration of 0.2 mmol/L, the target compounds had certain insecticidal and acaricidal activity, but they were not as effective as the control agent chlorfenapyr (corrected mortality 100%). The results of nematicidal bioassay showed good nematicidal activity of the target compounds. The LC50 values of compound 2 and 5b against Caenorhabditis elegans were 0.0136 and 0.0109 mmol/L, respectively, which were better than the control agent fosthiazate (0.2798 mmol/L). The preliminary safety test showed that the highly active target compound was safer to Oryza sativa L. and Brassica campestris L. than the parent tralopyril. The target compounds synthesized in this study have certain fungicidal, insecticidal, acaricidal and nematicidal activities, which provide a guideline for the design and transformation of tralopyril derivatives and are of reference significance for exploring the biological activities diversity of tralopyril derivatives.
In order to find novel pesticide-active compounds, a series of new 2-(tralopyril-1-yl) ethyl carboxylic acid derivatives ( 5a-5m , 6a-6o ) were synthesized by nucleophilic substitution with tralopyril as the lead compound. Their structures were confirmed by 1H NMR, 13C NMR and HRMS. The results of fungicidal bioassay showed that compounds 2 , 3 and 5m exhibited good fungicidal activity against Magnaporthe oryzae with EC50 values of 0.0532, 0.0470 and 0.0174 mmol/L, respectively, which were better than the control agent fludioxonil (0.0914 mmol/L), but inferior to the control agent azoxystrobin (0.0001 mmol/L). Compound 5m showed a broad spectrum of fungicidal activity, and its EC50 values for the control of Rhizoctonia solani and Bipolaris sorokiniana were 0.0218 and 0.0420 mmol/L, respectively, but inferior to the control agent fludioxonil (EC50 values were 0.0002 and 0.0010 mmol/L, respectively). The bioassay results of insecticidal and acaricidal showed that at the concentration of 0.2 mmol/L, the target compounds had certain insecticidal and acaricidal activity, but they were not as effective as the control agent chlorfenapyr (corrected mortality 100%). The results of nematicidal bioassay showed good nematicidal activity of the target compounds. The LC50 values of compound 2 and 5b against Caenorhabditis elegans were 0.0136 and 0.0109 mmol/L, respectively, which were better than the control agent fosthiazate (0.2798 mmol/L). The preliminary safety test showed that the highly active target compound was safer to Oryza sativa L. and Brassica campestris L. than the parent tralopyril. The target compounds synthesized in this study have certain fungicidal, insecticidal, acaricidal and nematicidal activities, which provide a guideline for the design and transformation of tralopyril derivatives and are of reference significance for exploring the biological activities diversity of tralopyril derivatives.
, Available online ,
doi: 10.16801/j.issn.1008-7303.2022.0138
Abstract:
With the flourishing development of nanotechnology, traditional pesticides are also injected new vigor. Electrospinning is a flexible, efficient, convenient and fast microfiber processing and manufacturing technology. In recent years, this technology is developed and applied to the field of pesticides based on the principles of functional modification of electrospinning micro-nanofibers, drug slow and controlled release, adsorption of trace compounds, and clean filtration. In this paper, the application status of electrospinning technology in the field of pesticides is reviewed, focused on the research progress in pesticide delivery carrier, pesticide residue analysis and detection, and pesticide pollution control and the problems and possible challenges encountered in the development of this technology were discussed and suggested, the purpose is to provide reference for the research and development and application of electrospinning in the field of pesticides.
With the flourishing development of nanotechnology, traditional pesticides are also injected new vigor. Electrospinning is a flexible, efficient, convenient and fast microfiber processing and manufacturing technology. In recent years, this technology is developed and applied to the field of pesticides based on the principles of functional modification of electrospinning micro-nanofibers, drug slow and controlled release, adsorption of trace compounds, and clean filtration. In this paper, the application status of electrospinning technology in the field of pesticides is reviewed, focused on the research progress in pesticide delivery carrier, pesticide residue analysis and detection, and pesticide pollution control and the problems and possible challenges encountered in the development of this technology were discussed and suggested, the purpose is to provide reference for the research and development and application of electrospinning in the field of pesticides.
, Available online ,
doi: 10.16801/j.issn.1008-7303.2022.0088
Abstract:
New diamide insecticides have been widely used to safeguard rice production. Chilo suppressalis (Walker), as a rice striped stem borer that harms rice production, has developed resistance to this type of insecticide. Further study on the molecular mechanism of resistance can provide technical support for the rapid detection of resistance and green control of C. suppressalis. Based on the current situation in resistance of C. suppressalis to diamide insecticides, the latest research advances in the resistance molecular mechanisms are summarized, including the overexpression of detoxification enzyme and transport genes mediated metabolic resistance and mutations of the ryanodine receptor gene mediated target resistance. The current existing issues in this research area mainly focus on the molecular detection of resistance, the identification of new resistance genes, the function and regulatory network of resistance genes, and the mechanism of multiple resistance. Future development directions have been prospected including resistance detection in the pest population by high throughput sequencing technology, identification of new resistance genes and resistance regulation networks for conformation of multiple resistance mechanisms using multi-omics technology, further functional verification of resistance genes by reverse genetics tools combined with radioligand binding analysis and electrophysiological technique, dsRNA transgenic crops targeting resistance genes, nano insecticides, and selective new chemical insecticides to reduce insecticides application and improve the efficiency of insecticides.
New diamide insecticides have been widely used to safeguard rice production. Chilo suppressalis (Walker), as a rice striped stem borer that harms rice production, has developed resistance to this type of insecticide. Further study on the molecular mechanism of resistance can provide technical support for the rapid detection of resistance and green control of C. suppressalis. Based on the current situation in resistance of C. suppressalis to diamide insecticides, the latest research advances in the resistance molecular mechanisms are summarized, including the overexpression of detoxification enzyme and transport genes mediated metabolic resistance and mutations of the ryanodine receptor gene mediated target resistance. The current existing issues in this research area mainly focus on the molecular detection of resistance, the identification of new resistance genes, the function and regulatory network of resistance genes, and the mechanism of multiple resistance. Future development directions have been prospected including resistance detection in the pest population by high throughput sequencing technology, identification of new resistance genes and resistance regulation networks for conformation of multiple resistance mechanisms using multi-omics technology, further functional verification of resistance genes by reverse genetics tools combined with radioligand binding analysis and electrophysiological technique, dsRNA transgenic crops targeting resistance genes, nano insecticides, and selective new chemical insecticides to reduce insecticides application and improve the efficiency of insecticides.
, Available online ,
doi: 10.16801/j.issn.1008-7303.2023.0015
Abstract:
Triadimefon is an important pesticide for controlling rubber tree powdery mildew. Clarifying translocation and enrichment behaviors of triadimefon and its metabolite triadimenol contributes to its high utilization on rubber trees. In this study, the residue analysis of triadimefon and triadimenol in the root, stem and leaf of rubber tree plants was established for the first time based on the QuEChERS-GC-MS/MS method. The translocation and enrichment behaviors of triadimefon and its metabolite triadimenol in rubber tree plants were determined by root application under hydroponic conditions and foliar application under soil culture. The results showed that rubber tree plants could rapidly metabolize triadimefon to triadimenol, and both chemicals could transport from plant roots to the leaves through the stem, but their enrichment behaviors in each part of the plant were significantly different. The bioconcentration factors were the order of root>stem>leaf, and the translocation factors of both stem and leaf were less than 1, indicating that triadimefon and its metabolite triadimenol were difficult to migrate upward in rubber tree plants and easily enriched by roots. Triadimefon was also rapidly metabolized to triadimefon under foliar application on rubber leaves. The two pesticides have poor translocation ability between the leaves of different parts of the plant. This study provides important data to optimize the application scheme of triadimefon and other pesticides on rubber trees.
Triadimefon is an important pesticide for controlling rubber tree powdery mildew. Clarifying translocation and enrichment behaviors of triadimefon and its metabolite triadimenol contributes to its high utilization on rubber trees. In this study, the residue analysis of triadimefon and triadimenol in the root, stem and leaf of rubber tree plants was established for the first time based on the QuEChERS-GC-MS/MS method. The translocation and enrichment behaviors of triadimefon and its metabolite triadimenol in rubber tree plants were determined by root application under hydroponic conditions and foliar application under soil culture. The results showed that rubber tree plants could rapidly metabolize triadimefon to triadimenol, and both chemicals could transport from plant roots to the leaves through the stem, but their enrichment behaviors in each part of the plant were significantly different. The bioconcentration factors were the order of root>stem>leaf, and the translocation factors of both stem and leaf were less than 1, indicating that triadimefon and its metabolite triadimenol were difficult to migrate upward in rubber tree plants and easily enriched by roots. Triadimefon was also rapidly metabolized to triadimefon under foliar application on rubber leaves. The two pesticides have poor translocation ability between the leaves of different parts of the plant. This study provides important data to optimize the application scheme of triadimefon and other pesticides on rubber trees.
, Available online ,
doi: 10.16801/j.issn.1008-7303.2023.0009
Abstract:
In order to explore the effect of rice seed treatment suspension (FS) on the growth of rice in dry land cultivation. In this paper, two seed treatment suspensions, i.e., sedaxane + pylocyanonitrile + metalaxyl 11% FS and clothianidin 18% FS were selected to treat rice seed (guang8you 1973). The effect of FS was assessed by standard germination, Q2 test, agronomic traits and yield. The results showed that: under laboratory conditions, germination vigor, germination percentage and increased metabolism time (IMT) of two FS with the 1 : 50 treatment (1 mL of agent is required to process 50 g of seeds, referred to as the ratio of FS to seed) had no significant effect on these parameter compare with the blank control under laboratory condition. However, the FS with the 1 : 50 treatment showed a shorter relative germination time (RGT), a higher starting metabolism rate (SMR), and the oxygen metabolism rate (OMR) was significantly higher than that of the blank control by 1.33% and 1.38% per hour, respectively. This results indicate that FS can improve seed respiration and seed vigor. The comparison between the two FS indicate that the clothianidin 18% FS had a better effect on seed vigor than the sedaxane + pylocyanonitrile + metalaxyl 11% FS under the field condition. The field performance was better than that of the blank control, among which the seedling rate of seed coating-agent treatment increased by 27.6%-33.20% compared with CK, the number of tillers increased by 71.14-97.82 per hectare, the plant height increased by 4.90-6.80 cm, the thousand-grain weight increased by 7.27%-9.09%, the effective panicle increased by 9.45-13.42 million panicles per hectare, and the actual yield increased by 529.85 kg/hm2 and 580.7 kg/hm2, and there were significant differences between them. The results showed that: coating rice seeds with sedaxane + pylocyanonitrile + metalaxyl 11% FS and clothianidin 18% FS at a seed ratio of 1 : 50 can effectively promote rice seed respiration, improve the performance and yield in dry land cultivation.
In order to explore the effect of rice seed treatment suspension (FS) on the growth of rice in dry land cultivation. In this paper, two seed treatment suspensions, i.e., sedaxane + pylocyanonitrile + metalaxyl 11% FS and clothianidin 18% FS were selected to treat rice seed (guang8you 1973). The effect of FS was assessed by standard germination, Q2 test, agronomic traits and yield. The results showed that: under laboratory conditions, germination vigor, germination percentage and increased metabolism time (IMT) of two FS with the 1 : 50 treatment (1 mL of agent is required to process 50 g of seeds, referred to as the ratio of FS to seed) had no significant effect on these parameter compare with the blank control under laboratory condition. However, the FS with the 1 : 50 treatment showed a shorter relative germination time (RGT), a higher starting metabolism rate (SMR), and the oxygen metabolism rate (OMR) was significantly higher than that of the blank control by 1.33% and 1.38% per hour, respectively. This results indicate that FS can improve seed respiration and seed vigor. The comparison between the two FS indicate that the clothianidin 18% FS had a better effect on seed vigor than the sedaxane + pylocyanonitrile + metalaxyl 11% FS under the field condition. The field performance was better than that of the blank control, among which the seedling rate of seed coating-agent treatment increased by 27.6%-33.20% compared with CK, the number of tillers increased by 71.14-97.82 per hectare, the plant height increased by 4.90-6.80 cm, the thousand-grain weight increased by 7.27%-9.09%, the effective panicle increased by 9.45-13.42 million panicles per hectare, and the actual yield increased by 529.85 kg/hm2 and 580.7 kg/hm2, and there were significant differences between them. The results showed that: coating rice seeds with sedaxane + pylocyanonitrile + metalaxyl 11% FS and clothianidin 18% FS at a seed ratio of 1 : 50 can effectively promote rice seed respiration, improve the performance and yield in dry land cultivation.
, Available online ,
doi: 10.16801/j.issn.1008-7303.2022.0143
Abstract:
Plant protection unmanned aerial vehicles (UAVs) are modern plant protection application machines with the characteristics of high operational efficiency, precision, water, and pesticides saving, flexibility and safety for sprayers, etc. However, unlike traditional application methods, the UAVs use less water with high pesticide concentration, and it is easy to drift with a high application risk. The current research on plant protection UAVs application mainly focuses on droplet deposition distribution, drift, and control efficiency. However, there are fewer studies on dietary, environmental and occupational exposure health risk assessment, and the standards and regulations for registration and management of formulation are relatively lagging. In order to comprehensively understand the application of plant protection UAVs and the current status of management, this paper reviews the application of plant protection UAVs, risk studies and international registration and management of aerial plant protection pesticides, and summarizes the development potential and management recommendations in this field in China, with a view to providing reference for the safe application of pesticides by plant protection UAVs and the scientific management of registration in China.
Plant protection unmanned aerial vehicles (UAVs) are modern plant protection application machines with the characteristics of high operational efficiency, precision, water, and pesticides saving, flexibility and safety for sprayers, etc. However, unlike traditional application methods, the UAVs use less water with high pesticide concentration, and it is easy to drift with a high application risk. The current research on plant protection UAVs application mainly focuses on droplet deposition distribution, drift, and control efficiency. However, there are fewer studies on dietary, environmental and occupational exposure health risk assessment, and the standards and regulations for registration and management of formulation are relatively lagging. In order to comprehensively understand the application of plant protection UAVs and the current status of management, this paper reviews the application of plant protection UAVs, risk studies and international registration and management of aerial plant protection pesticides, and summarizes the development potential and management recommendations in this field in China, with a view to providing reference for the safe application of pesticides by plant protection UAVs and the scientific management of registration in China.
, Available online ,
doi: 10.16801/j.issn.1008-7303.2022.0136
Abstract:
The discovery of pesticides with novel mode of action is crucial for modern crop protection. In present work, a series of novel piperidin-4-ol derivatives were synthesized by 5-step reactions using piperidinol and catechol as starting materials. All target compounds were characterized by 1H NMR, 13C NMR and HRMS. The biological activities of synthesized compounds were evaluated against Meloidogyne incognita and Pseudaletia separata Walker respectively. It was found that some target compounds exhibited good nematicidal activity against M. incognita at 25 mg/L. Obvious weight reduction on P. separata was also observed for most of the compounds at 500 mg/L due to their anti-feeding effects on the armyworm.
The discovery of pesticides with novel mode of action is crucial for modern crop protection. In present work, a series of novel piperidin-4-ol derivatives were synthesized by 5-step reactions using piperidinol and catechol as starting materials. All target compounds were characterized by 1H NMR, 13C NMR and HRMS. The biological activities of synthesized compounds were evaluated against Meloidogyne incognita and Pseudaletia separata Walker respectively. It was found that some target compounds exhibited good nematicidal activity against M. incognita at 25 mg/L. Obvious weight reduction on P. separata was also observed for most of the compounds at 500 mg/L due to their anti-feeding effects on the armyworm.
, Available online ,
doi: 10.16801/j.issn.1008-7303.2022.0130
Abstract:
The sensitivity of Fusarium graminearum to prothioconazole was determined with 278 strains collected from 11 cities in Henan Province from 2019 to 2021 using the method of mycelial growth rate in vitro. The results showed that the sensitivity frequency of 278 F. graminearum strains to prothioconazole was a unimodal curve and presented an approximately normal distribution. The EC50 values of the strains ranged from 0.609 to 3.868 μg/mL, with the maximum value being 6.35 times of the minimum value. The mean EC50 was (1.741 ± 0.690) μg/mL. In addition, the sensitivity of F. graminearum to propiconazole in different years had no significant difference. For different years, the strains collected in 2020 was the least sensitive with an average EC50 value of (1.894 ± 0.652) μg/mL, while the strains collected in 2021 was the most sensitive with an average EC50 value of (1.643 ± 0.701) μg/mL. The sensitivity of F. graminearum to prothioconazole had significant difference in different regions. The strains in Jiyuan were the least sensitive with an average EC50 value of (2.175 ± 0.632) μg/mL, while those in Kaifeng were the most sensitive with an average EC50 value of (1.137 ± 0.419) μg/mL. F. graminearum strains from Jiaozuo city were the most varied in sensitivity (EC50(Max.)/EC50 (Min.) = 6.21) with an average EC50 value of (2.073 ± 0.681) μg/mL, which was higher than the average of Henan Province. The strains from Xinxiang city have the smallest differences in sensitivity (EC50 (Max.)/EC50 (Min.) = 1.75) with an average EC50 value of (1.211 ± 0.349) μg/mL, which was lower than the average in Henan Province. This study provided a theoretical basis for the sensitivity of F. graminearum to prothioconazole in the future through continuous year sensitivity monitoring.
The sensitivity of Fusarium graminearum to prothioconazole was determined with 278 strains collected from 11 cities in Henan Province from 2019 to 2021 using the method of mycelial growth rate in vitro. The results showed that the sensitivity frequency of 278 F. graminearum strains to prothioconazole was a unimodal curve and presented an approximately normal distribution. The EC50 values of the strains ranged from 0.609 to 3.868 μg/mL, with the maximum value being 6.35 times of the minimum value. The mean EC50 was (1.741 ± 0.690) μg/mL. In addition, the sensitivity of F. graminearum to propiconazole in different years had no significant difference. For different years, the strains collected in 2020 was the least sensitive with an average EC50 value of (1.894 ± 0.652) μg/mL, while the strains collected in 2021 was the most sensitive with an average EC50 value of (1.643 ± 0.701) μg/mL. The sensitivity of F. graminearum to prothioconazole had significant difference in different regions. The strains in Jiyuan were the least sensitive with an average EC50 value of (2.175 ± 0.632) μg/mL, while those in Kaifeng were the most sensitive with an average EC50 value of (1.137 ± 0.419) μg/mL. F. graminearum strains from Jiaozuo city were the most varied in sensitivity (EC50(Max.)/EC50 (Min.) = 6.21) with an average EC50 value of (2.073 ± 0.681) μg/mL, which was higher than the average of Henan Province. The strains from Xinxiang city have the smallest differences in sensitivity (EC50 (Max.)/EC50 (Min.) = 1.75) with an average EC50 value of (1.211 ± 0.349) μg/mL, which was lower than the average in Henan Province. This study provided a theoretical basis for the sensitivity of F. graminearum to prothioconazole in the future through continuous year sensitivity monitoring.
, Available online ,
doi: 10.16801/j.issn.1008-7303.2022.0121
Abstract:
Diamide pesticides are a class of insecticides attracting great attention after neonicotinoids. The action target of diamide insecticides is ryanodine receptor or γ-aminobutyric acid receptor, which exhibits extraordinary potency on lepidopteran pests. With the widespread of diamide pesticides, the potential threat to non-target organisms and aquatic ecosystem and the resistance of target pests have been observed. This manuscript aims to summarize the biological activity, ecological toxicity, analytical methodology, environmental fate and risk assessment of diamide pesticides based on the research progress at home and abroad. The corresponding research orientations are also prospected to provide scientific references for accurate application, risk aversion and effective management of diamide pesticides.
Diamide pesticides are a class of insecticides attracting great attention after neonicotinoids. The action target of diamide insecticides is ryanodine receptor or γ-aminobutyric acid receptor, which exhibits extraordinary potency on lepidopteran pests. With the widespread of diamide pesticides, the potential threat to non-target organisms and aquatic ecosystem and the resistance of target pests have been observed. This manuscript aims to summarize the biological activity, ecological toxicity, analytical methodology, environmental fate and risk assessment of diamide pesticides based on the research progress at home and abroad. The corresponding research orientations are also prospected to provide scientific references for accurate application, risk aversion and effective management of diamide pesticides.
, Available online ,
doi: 10.16801/j.issn.1008-7303.2022.0105
Abstract:
Isoxazole is a five-membered heterocycle with good activity. Fifteen new 5-methylisoxazole-4-carboxylic oxime esters were designed and synthesized in this paper. Their structures were determined by 1H NMR, 13C NMR and HRMS. The in vitro antifungal activities against Botrytis cinerea, Rhizoctonia solani, Valsa mali and Gaeumannomyces graminis were evaluated. The bioactivity results showed that the target compounds had certain antifungal activities at the concentration of 50 μg/mL. Particularly, compound 5g displayed better activity against B. cinerea than lead compound L1 and trifloxystrobin with an EC50 value of 1.95 μg/mL.
Isoxazole is a five-membered heterocycle with good activity. Fifteen new 5-methylisoxazole-4-carboxylic oxime esters were designed and synthesized in this paper. Their structures were determined by 1H NMR, 13C NMR and HRMS. The in vitro antifungal activities against Botrytis cinerea, Rhizoctonia solani, Valsa mali and Gaeumannomyces graminis were evaluated. The bioactivity results showed that the target compounds had certain antifungal activities at the concentration of 50 μg/mL. Particularly, compound 5g displayed better activity against B. cinerea than lead compound L1 and trifloxystrobin with an EC50 value of 1.95 μg/mL.
, Available online ,
doi: 10.16801/j.issn.1008-7303.2022.0135
Abstract:
Plant viruses have a great adverse impact on vegetable production. Non-pharmaceutical measures are mainly adopted for vegetable virus prevention and control at present. However, the efficacy of broad-spectrum antiviral agents is limited. The new viral inhibitors are expected to be developed based on novel drug targets. G-quadruplex (G4s) is a non-canonical nucleic acid structure. The replication, transcription, and translation of genes can be regulated by the formation or unfolding of G-quadruplexes in the genome, which affects virus proliferation. Small molecules mediating the stability of G-quadruplex structures exhibit antiviral activity, making G-quadruplexes to be potential antiviral targets. As a widely distributed plant virus, tomato bushy stunt virus (TBSV) is considered as a model virus to study the interaction between the virus and host. The molecular mechanisms of its genome replication, transcription, and translation have been widely studied. Revealing the structure and function of G-quadruplex in TBSV is expected to lay a foundation for the research of G-quadruplex in plant virus genes. In this work, two conserved potential G-quadruplex sequences (Putative G-quadruplex sequences, PQS) TBSV-PQS2 and TBSV-PQS4 were identified in TBSV genes through bioinformatics analysis. The G4 ligands interacting with TBSV-PQS2 and TBSV-PQS4 were screened out by UV fluorescence spectrum and circular dichroism (CD) spectrum. Invasive cloning experiments in tobacco found that G-quadruplex ligand N-methyl mesophorphyrin IX (NMM) inhibits TBSV virus proliferation. This work shows that the development of ecological pesticides against plant viruses by targeting the G-quadruplex in plant viruses is expected to become a new strategy for controlling the damage of plant viruses.
Plant viruses have a great adverse impact on vegetable production. Non-pharmaceutical measures are mainly adopted for vegetable virus prevention and control at present. However, the efficacy of broad-spectrum antiviral agents is limited. The new viral inhibitors are expected to be developed based on novel drug targets. G-quadruplex (G4s) is a non-canonical nucleic acid structure. The replication, transcription, and translation of genes can be regulated by the formation or unfolding of G-quadruplexes in the genome, which affects virus proliferation. Small molecules mediating the stability of G-quadruplex structures exhibit antiviral activity, making G-quadruplexes to be potential antiviral targets. As a widely distributed plant virus, tomato bushy stunt virus (TBSV) is considered as a model virus to study the interaction between the virus and host. The molecular mechanisms of its genome replication, transcription, and translation have been widely studied. Revealing the structure and function of G-quadruplex in TBSV is expected to lay a foundation for the research of G-quadruplex in plant virus genes. In this work, two conserved potential G-quadruplex sequences (Putative G-quadruplex sequences, PQS) TBSV-PQS2 and TBSV-PQS4 were identified in TBSV genes through bioinformatics analysis. The G4 ligands interacting with TBSV-PQS2 and TBSV-PQS4 were screened out by UV fluorescence spectrum and circular dichroism (CD) spectrum. Invasive cloning experiments in tobacco found that G-quadruplex ligand N-methyl mesophorphyrin IX (NMM) inhibits TBSV virus proliferation. This work shows that the development of ecological pesticides against plant viruses by targeting the G-quadruplex in plant viruses is expected to become a new strategy for controlling the damage of plant viruses.
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2023, 25(1): 1-11.
doi: 10.16801/j.issn.1008-7303.2022.0116
Abstract:
RNA interference (RNAi) is a highly conserved gene silencing phenomenon in eukaryotes, which has shown broad potential application in medicine and plant protection. Recently, RNAi-related products have been or about to been in the pharmaceutical and pesticide markets. For RNAi-based fungicides, although researchers have made a lot of efforts in the development of its products, the commercial application of RNAi against plant pathogens has not arrived on the market yet. Here, the development of RNAi research since 1990 is summarized, and new ideas that may help improve the development of RNAi-based fungicides are introduced. At the same time, the influence of RNAi-based fungicides on traditional chemical fungicides is discussed, which is the innovation and application of RNAi fungicides.
RNA interference (RNAi) is a highly conserved gene silencing phenomenon in eukaryotes, which has shown broad potential application in medicine and plant protection. Recently, RNAi-related products have been or about to been in the pharmaceutical and pesticide markets. For RNAi-based fungicides, although researchers have made a lot of efforts in the development of its products, the commercial application of RNAi against plant pathogens has not arrived on the market yet. Here, the development of RNAi research since 1990 is summarized, and new ideas that may help improve the development of RNAi-based fungicides are introduced. At the same time, the influence of RNAi-based fungicides on traditional chemical fungicides is discussed, which is the innovation and application of RNAi fungicides.
2023, 25(1): 12-22.
doi: 10.16801/j.issn.1008-7303.2023.0007
Abstract:
In view of the issues of dietary risk assessment of pesticide residues in foods in China, discussion of the following aspects of related concerns were conducted. First, the relevance and the scientific justifications of conducting risk assessment of pesticide residues in foods. Second, the way of dealing with the relationship between each part of pesticide residue risk assessment. Third, the three key elements of dietary risk assessment (toxicology, residue chemistry, and food consumption) and their significance. Fourth, paying more attention to the scenarios, scales, and data requirements for the assessment. Finally, conclusions and recommendations to be made for risk management. During the aforementioned discussion, some existing issues of risk assessment and risk management of pesticide residues in foods in China were analyzed, and recommendations for improvements were proposed in the review.
2023, 25(1): 23-34.
doi: 10.16801/j.issn.1008-7303.2022.0142
Abstract:
Pesticides have a significant effect in controlling pests and diseases and improving the output and quality of agricultural products. However, some pesticides have been banned or restricted in China due to their high toxicity, carcinogenicity, teratogenicity, mutagenicity, and slow metabolism, which may cause the adverse effects on human beings and the environment. Organochlorine pesticides are the largest in production and consumption of the banned and restricted pesticides, which have been raised concerns for their potentially high health or environmental risks. The establishment of efficient and convenient detection methods for the banned and restricted pesticides of organochlorine residues is of great significance to ensure food safety, promote the development of green ecological agriculture, and break the technical trade barriers in food imports and exports. Immunoassay has been widely used in the detection of pesticide residues in food for its advantages of rapidity, simplicity and sensitivity. In this paper, the research progress of immunoassay methods for the banned and restricted organochlorine pesticides is reviewed, the synthesis of haptens and the preparation of antibodies are introduced, and the application of the antibodies in immunoassay (mainly including enzyme-linked immunoassay, immunochromatographic test strip, chemiluminescence immunoassay, fluorescence immunoassay and immunosensor) is summarized. It provides a reference for research on immunoassay for the banned and restricted organochlorine pesticides in the future.
Pesticides have a significant effect in controlling pests and diseases and improving the output and quality of agricultural products. However, some pesticides have been banned or restricted in China due to their high toxicity, carcinogenicity, teratogenicity, mutagenicity, and slow metabolism, which may cause the adverse effects on human beings and the environment. Organochlorine pesticides are the largest in production and consumption of the banned and restricted pesticides, which have been raised concerns for their potentially high health or environmental risks. The establishment of efficient and convenient detection methods for the banned and restricted pesticides of organochlorine residues is of great significance to ensure food safety, promote the development of green ecological agriculture, and break the technical trade barriers in food imports and exports. Immunoassay has been widely used in the detection of pesticide residues in food for its advantages of rapidity, simplicity and sensitivity. In this paper, the research progress of immunoassay methods for the banned and restricted organochlorine pesticides is reviewed, the synthesis of haptens and the preparation of antibodies are introduced, and the application of the antibodies in immunoassay (mainly including enzyme-linked immunoassay, immunochromatographic test strip, chemiluminescence immunoassay, fluorescence immunoassay and immunosensor) is summarized. It provides a reference for research on immunoassay for the banned and restricted organochlorine pesticides in the future.
2023, 25(1): 35-50.
doi: 10.16801/j.issn.1008-7303.2022.0132
Abstract:
It is a further guarantee for food safety to remove pesticide residues in fruits and vegetables by washing and cleaning approaches including ozone treatment. In this paper, the studies on removal of pesticide residues in fruits and vegetables by ozone treatment were reviewed, which involved the ozone generation method, application form, and the combination application of ozone with other methods. The factors affecting the removal rate of pesticide residues and the effects of these treatments on the appearance and nutrition of fruits and vegetables were summarized. The action mechanism of ozone on removal of pesticide residues was further explored. This review aims to provide theoretical and application reference for the researches on the ozone treatment technology used to remove pesticide residues in fruits and vegetables.
It is a further guarantee for food safety to remove pesticide residues in fruits and vegetables by washing and cleaning approaches including ozone treatment. In this paper, the studies on removal of pesticide residues in fruits and vegetables by ozone treatment were reviewed, which involved the ozone generation method, application form, and the combination application of ozone with other methods. The factors affecting the removal rate of pesticide residues and the effects of these treatments on the appearance and nutrition of fruits and vegetables were summarized. The action mechanism of ozone on removal of pesticide residues was further explored. This review aims to provide theoretical and application reference for the researches on the ozone treatment technology used to remove pesticide residues in fruits and vegetables.
2023, 25(1): 51-61.
doi: 10.16801/j.issn.1008-7303.2022.0125
Abstract:
Traditional pesticide formulations such as emulsifiable oil and wettable powder have the disadvantages of high toxicity, low biological activity, short duration, and low utilization rate. In recent years, nanotechnology has been widely used in the field of agriculture and nano-pesticides based on metal-organic frameworks (MOFs) have the characteristics of small particle size, large specific surface area, strong adhesion, targeted transport and controlled release, which provides a new solution for realizing precise application, long duration and high utilization rate of pesticides. In this review, the hydrothermal/solvothermal, one-pot, and sol-gel methods for preparing MOFs nanocarriers are introduced, and the functional modification strategies of MOFs nanocarriers, including adjustment, post-synthesis, and complex modification are summarized. The sustained and controlled release applications of MOFs nanocomposites in fungicides, insecticides, and plant growth regulators are highlighted. Finally, the problems and development trends of pesticide nano-carriers based on MOFs are prospected to guide subsequent related research.
Traditional pesticide formulations such as emulsifiable oil and wettable powder have the disadvantages of high toxicity, low biological activity, short duration, and low utilization rate. In recent years, nanotechnology has been widely used in the field of agriculture and nano-pesticides based on metal-organic frameworks (MOFs) have the characteristics of small particle size, large specific surface area, strong adhesion, targeted transport and controlled release, which provides a new solution for realizing precise application, long duration and high utilization rate of pesticides. In this review, the hydrothermal/solvothermal, one-pot, and sol-gel methods for preparing MOFs nanocarriers are introduced, and the functional modification strategies of MOFs nanocarriers, including adjustment, post-synthesis, and complex modification are summarized. The sustained and controlled release applications of MOFs nanocomposites in fungicides, insecticides, and plant growth regulators are highlighted. Finally, the problems and development trends of pesticide nano-carriers based on MOFs are prospected to guide subsequent related research.
2023, 25(1): 62-72.
doi: 10.16801/j.issn.1008-7303.2022.0102
Abstract:
Compounds bearing structurally unique isoquinolin-1(2H)-one scaffold were found to be widely distributed in various organisms and they exhibited a broad spectrum of biological activities. In the present study, 22 derivatives of the isoquinolin-1(2H)-one scaffold were synthesized by Castagnoli-Cushman reaction and esterification reaction and their antifungal activity was evaluated against 7 phytopathogens. The in vitro bioassay results indicated that the mycelial growth inhibition rates of compounds 5a-5k and 6a-6f were higher than 80% against Sclerotinia sclerotiorum at the concentration of 100 μg/mL. Compound 5k was the most potent activity with the EC50 value of 5.8 μg/mL, which was lower than the commercial boscalid (EC50 = 0.094 μg/mL). The structure-activity relationship analysis revealed that the phenyl on N atom site is superior to the alkyl, and the introduction of different substituents to the phenyl group could improve the antifungal activity, which was subject to the positional selectivity and the number of substituents on the phenyl group. However, introducing different substituents at C3 phenyl and C4 carboxyl group were unfavorable for the activity. The preventive control efficacy of 5k was 94.6% at 500 μg/mL, which was comparable to that of boscalid at 10 μg/mL (95.8%). Taken together, these results could provide some important cues for further optimization of tetrahydroisoquinolone-4-carboxylic acid derivatives.
Compounds bearing structurally unique isoquinolin-1(2H)-one scaffold were found to be widely distributed in various organisms and they exhibited a broad spectrum of biological activities. In the present study, 22 derivatives of the isoquinolin-1(2H)-one scaffold were synthesized by Castagnoli-Cushman reaction and esterification reaction and their antifungal activity was evaluated against 7 phytopathogens. The in vitro bioassay results indicated that the mycelial growth inhibition rates of compounds 5a-5k and 6a-6f were higher than 80% against Sclerotinia sclerotiorum at the concentration of 100 μg/mL. Compound 5k was the most potent activity with the EC50 value of 5.8 μg/mL, which was lower than the commercial boscalid (EC50 = 0.094 μg/mL). The structure-activity relationship analysis revealed that the phenyl on N atom site is superior to the alkyl, and the introduction of different substituents to the phenyl group could improve the antifungal activity, which was subject to the positional selectivity and the number of substituents on the phenyl group. However, introducing different substituents at C3 phenyl and C4 carboxyl group were unfavorable for the activity. The preventive control efficacy of 5k was 94.6% at 500 μg/mL, which was comparable to that of boscalid at 10 μg/mL (95.8%). Taken together, these results could provide some important cues for further optimization of tetrahydroisoquinolone-4-carboxylic acid derivatives.
2023, 25(1): 73-80.
doi: 10.16801/j.issn.1008-7303.2022.0106
Abstract:
Seventeen novel derivatives of hinokitiol, a monoterpene with a troponoide skeleton, were designed and synthesized. Their structures were confirmed by NMR and HRMS. The in vitro bioassay results showed that the target compounds displayed satisfactory antifungal activities against Rhizoctonia solani, Botrytis cinerea, Sclerotinia sclerotiorum, Valsa mali and Colletotrichum orbiculare at 50 μg/mL. Notably, compound 3a showed favorable activity against R. solani (EC50 = 1.84 μg/mL), 3j exhibited satisfied activity against B. cinerea (EC50 = 2.47 μg/mL), and 3m exerted excellent activity against S. sclerotiorum (EC50 = 1.05 μg/mL), which are better than hinokitiol (2.00, 11.3 and 5.40 μg/mL).
Seventeen novel derivatives of hinokitiol, a monoterpene with a troponoide skeleton, were designed and synthesized. Their structures were confirmed by NMR and HRMS. The in vitro bioassay results showed that the target compounds displayed satisfactory antifungal activities against Rhizoctonia solani, Botrytis cinerea, Sclerotinia sclerotiorum, Valsa mali and Colletotrichum orbiculare at 50 μg/mL. Notably, compound 3a showed favorable activity against R. solani (EC50 = 1.84 μg/mL), 3j exhibited satisfied activity against B. cinerea (EC50 = 2.47 μg/mL), and 3m exerted excellent activity against S. sclerotiorum (EC50 = 1.05 μg/mL), which are better than hinokitiol (2.00, 11.3 and 5.40 μg/mL).
2023, 25(1): 81-88.
doi: 10.16801/j.issn.1008-7303.2022.0117
Abstract:
Tobacco sore shin caused by Rhizoctonia solani is one of the most destructive diseases in the seedbed suffered by tobacco in China. This study evaluated the activities of the fungicides azoxystrobin, boscalid, fluazinam, propiconazole, and pyrimethanil against mycelial growth, sclerotia formation and germination of R. solani, and also their protective and curative efficacies against tobacco sore shin. The mycelial growth of R. solani was more sensitive to fluazinam and azoxystrobin than to propiconazole and boscalid, and least sensitive to pyrimethanil. Azoxystrobin showed stronger inhibition of sclerotia production than propiconazole, fluazinam, pyrimethanil, and boscalid. None of the five fungicides inhibited the sclerotia germination of R. solani. In terms of the protective activity of detached tobacco leaves, azoxystrobin and boscalid at 12.5 and 50 mg/L were superior to fluazinam, propiconazole, and pyrimethanil in reducing sore shin. For curative activity, azoxystrobin at 50 and 200 mg/L was superior to the other four fungicides in reducing disease. Therefore, among the five fungicides, azoxystrobin is most suitable for the control of tobacco sore shin.
2023, 25(1): 89-96.
doi: 10.16801/j.issn.1008-7303.2022.0145
Abstract:
In order to explore the feasibility of pyraclostrobin in preventing diseases of wheat at different growth stages, the virulences of pyraclostrobin against the causal agents of wheat sheath blight (Rhizoctonia cerealis), root rot (Bipolaris sorokiniana), total rot (Gaeumannomyces tritici), and head blight (Gibberella zeae) were determined by the mycelial growth rate method. Using the seed germination test, the effect of different concentrations of pyraclostrobin coating on wheat seed germination was determined. The control effects of pyraclostrobin 5% FS on wheat sheath blight in pots were determined by the bacteria-soil mixing method and the field control effects of pyraclostrobin 5% SC against R. cerealis, B. sorokiniana, G. tritici, and G. zeae were also determined. The results showed that the EC50 value of pyraclostrobin against R. cerealis, B. sorokiniana, G. tritici, and G. zeae were 0.404, 5.862, 0.193, and 1.372 mg/L, respectively. Different coating ratios of pyraclostrobin 5% FS had a certain promotion effect on the fresh weight and dry weight of Jimai 22 under the condition of 25 ℃ and showed a certain promotion effect on the germination potential, germination rate, germination index, and vigor index of wheat seeds under the condition of 10 ℃. The pot experiment showed that pyraclostrobin 5% FS had a control efficacy of more than 74% on wheat sheath blight 20 days after seedling, and the control efficacy reached 99.02% when the coating ratio was 1∶50. The control efficacies of pyraclostrobin 5% SC on wheat powdery mildew, rust and scab were 100%, 100%, and 75.87% respectively under the dose of 3000 mL/hm2 with two sprays during early flowering and full flowering periods. The research showed that pyraclostrobin can be well applied to the control of wheat diseases in different growth stages.
In order to explore the feasibility of pyraclostrobin in preventing diseases of wheat at different growth stages, the virulences of pyraclostrobin against the causal agents of wheat sheath blight (Rhizoctonia cerealis), root rot (Bipolaris sorokiniana), total rot (Gaeumannomyces tritici), and head blight (Gibberella zeae) were determined by the mycelial growth rate method. Using the seed germination test, the effect of different concentrations of pyraclostrobin coating on wheat seed germination was determined. The control effects of pyraclostrobin 5% FS on wheat sheath blight in pots were determined by the bacteria-soil mixing method and the field control effects of pyraclostrobin 5% SC against R. cerealis, B. sorokiniana, G. tritici, and G. zeae were also determined. The results showed that the EC50 value of pyraclostrobin against R. cerealis, B. sorokiniana, G. tritici, and G. zeae were 0.404, 5.862, 0.193, and 1.372 mg/L, respectively. Different coating ratios of pyraclostrobin 5% FS had a certain promotion effect on the fresh weight and dry weight of Jimai 22 under the condition of 25 ℃ and showed a certain promotion effect on the germination potential, germination rate, germination index, and vigor index of wheat seeds under the condition of 10 ℃. The pot experiment showed that pyraclostrobin 5% FS had a control efficacy of more than 74% on wheat sheath blight 20 days after seedling, and the control efficacy reached 99.02% when the coating ratio was 1∶50. The control efficacies of pyraclostrobin 5% SC on wheat powdery mildew, rust and scab were 100%, 100%, and 75.87% respectively under the dose of 3000 mL/hm2 with two sprays during early flowering and full flowering periods. The research showed that pyraclostrobin can be well applied to the control of wheat diseases in different growth stages.
2023, 25(1): 97-103.
doi: 10.16801/j.issn.1008-7303.2022.0082
Abstract:
In order to screen out the chemical agents for controlling wheat leaf rust, pyraclostrobin, epoxiconazole and their combinations with different proportions were evaluated in this study, and the indoor control efficacies on wheat leaf rust as protective agents were determined by spray inoculation method, the safety on wheat and the field control efficacy of wheat leaf rust of the optimal compound ratio for indoor screening were investigated. The results showed that pyraclostrobin, epoxiconazole and their combination had strong inhibitory effect on the lesion expansion of wheat leaf rust. Among them, pyraclostrobin had stronger inhibitory activity, and its EC50 value was 0.01 μg/mL. The results of joint toxicity evaluation showed that all combinations showed a synergistic additive efficacy, and the maximum synergistic coefficient was 1.50 with the mass ratio of pyraclostrobin-epoxiconazole as 50∶133. Both the indoor and field tests showed that the control efficacy was positively correlated with the established concentration gradient. In the field test with 120 a.i. g/hm2, the control efficacy of pyraclostrobin + epoxiconazole 26% SC was 85.12%, which was better than that of single-agent treatments. The safety evaluation tests showed that all treatments could make different varieties of wheat grow normally without drug damage. This study had shown that the combination of pyraclostrobin and epoxiconazole had a good control efficacy on wheat leaf rust, providing a theoretical basis for the prevention and control of wheat leaf rust and scientific medication in production.
In order to screen out the chemical agents for controlling wheat leaf rust, pyraclostrobin, epoxiconazole and their combinations with different proportions were evaluated in this study, and the indoor control efficacies on wheat leaf rust as protective agents were determined by spray inoculation method, the safety on wheat and the field control efficacy of wheat leaf rust of the optimal compound ratio for indoor screening were investigated. The results showed that pyraclostrobin, epoxiconazole and their combination had strong inhibitory effect on the lesion expansion of wheat leaf rust. Among them, pyraclostrobin had stronger inhibitory activity, and its EC50 value was 0.01 μg/mL. The results of joint toxicity evaluation showed that all combinations showed a synergistic additive efficacy, and the maximum synergistic coefficient was 1.50 with the mass ratio of pyraclostrobin-epoxiconazole as 50∶133. Both the indoor and field tests showed that the control efficacy was positively correlated with the established concentration gradient. In the field test with 120 a.i. g/hm2, the control efficacy of pyraclostrobin + epoxiconazole 26% SC was 85.12%, which was better than that of single-agent treatments. The safety evaluation tests showed that all treatments could make different varieties of wheat grow normally without drug damage. This study had shown that the combination of pyraclostrobin and epoxiconazole had a good control efficacy on wheat leaf rust, providing a theoretical basis for the prevention and control of wheat leaf rust and scientific medication in production.
2023, 25(1): 104-116.
doi: 10.16801/j.issn.1008-7303.2022.0122
Abstract:
Turf dollar spot, caused by Clarireedia spp., is one of the most destructive fungal diseases on turf. 6-Pentyl-2H-pyran-2-one (6PP) is a critical antifungal secondary metabolite produced by Trichoderma spp. In order to explore the antifungal activity of 6PP against Clarireedia spp. and its control efficacy to Turf dollar spot, the inhibition activity of 6PP on Clarireedia spp. was measured by mycelial growth rate method, and the protective and curative activities of 6PP against the disease was measured on detached leaves and potted plants. The changes in mycelial structure and activities of stress resistance related enzyme of the pathogens under 6PP treatment were analyzed. The results showed that 6PP had efficient inhibition activity on C. jacksonii and C. monteithiana. The average effective inhibitory medium concentration (EC50) of 6PP to C. monteithiana was 0.37 μg/mL, and the average EC50 value to C. jacksonii was 0.04 μg/mL. After being treated with 6PP, mycelial of both C. jacksonii and C. monteithiana grew abnormally, cell membrane permeability and relative conductivity as well as peroxidated cell membrane increased. The peroxidase (POD) activity of C. jacksonii increased significantly although its pH remained unchanged, while the superoxide dismutase (SOD) activity, pH and exopolysaccharides (EPS) of C. monteithiana increased significantly. The preventive effects of 1 μg/mL 6PP on dollar spot were 91.14% in vitro and 72.21% in pots. 6PP has a significant inhibitory effect on Turf dollar spot and has a good control efficacy on the disease in vitro and in pots. The study revealed the potential of 6PP to be an eco-friendly fungicide preventing Turf dollar spot.
Turf dollar spot, caused by Clarireedia spp., is one of the most destructive fungal diseases on turf. 6-Pentyl-2H-pyran-2-one (6PP) is a critical antifungal secondary metabolite produced by Trichoderma spp. In order to explore the antifungal activity of 6PP against Clarireedia spp. and its control efficacy to Turf dollar spot, the inhibition activity of 6PP on Clarireedia spp. was measured by mycelial growth rate method, and the protective and curative activities of 6PP against the disease was measured on detached leaves and potted plants. The changes in mycelial structure and activities of stress resistance related enzyme of the pathogens under 6PP treatment were analyzed. The results showed that 6PP had efficient inhibition activity on C. jacksonii and C. monteithiana. The average effective inhibitory medium concentration (EC50) of 6PP to C. monteithiana was 0.37 μg/mL, and the average EC50 value to C. jacksonii was 0.04 μg/mL. After being treated with 6PP, mycelial of both C. jacksonii and C. monteithiana grew abnormally, cell membrane permeability and relative conductivity as well as peroxidated cell membrane increased. The peroxidase (POD) activity of C. jacksonii increased significantly although its pH remained unchanged, while the superoxide dismutase (SOD) activity, pH and exopolysaccharides (EPS) of C. monteithiana increased significantly. The preventive effects of 1 μg/mL 6PP on dollar spot were 91.14% in vitro and 72.21% in pots. 6PP has a significant inhibitory effect on Turf dollar spot and has a good control efficacy on the disease in vitro and in pots. The study revealed the potential of 6PP to be an eco-friendly fungicide preventing Turf dollar spot.
2023, 25(1): 117-125.
doi: 10.16801/j.issn.1008-7303.2022.0124
Abstract:
In order to explore the application technology of pentoxazone in direct-seeding rice fields, the control spectrum, biological activity, and safety of pentoxazone to eight varieties of rice were determined in the greenhouse, and its control efficacy in the field was verified. The results showed that when the dose of the active ingredient was 225 g/hm2, the inhibition rates of pentoxazone on fresh weight of five kinds of weeds including Eleusine indica, Cyperus difformis, Eclipta prostrata, Cyperus rotundus, and Cyperus iria were all more than 90%, and the GR50 (active ingredient, the same as the rest) of pentoxazone on main weeds such as Echinochloa crus-galli, Digitaria sanguinalis, E. prostrate, and C. iria were between 82.15 g/hm2 and 189.17 g/hm2. The safety results showed that when the dose of the active ingredient was 1800 g/hm2, it was safe for the eight tested rice varieties, with plant height inhibition rates of 1.89%-5.16%, and fresh weight inhibition rates of 1.47%-4.14%. The selectivity indexes of pentoxazone between four rice varieties Longliangyouhuazhan, Ziliangyou 5, Nanjing 9108, Nanjing 46, and four weeds E. crus-galli, D. sanguinalis, E. prostrate, C. iria were 3.27-28.24, and its selectivities between rice and E. prostrate, and C. iria were significantly better than that of oxydiazon. At 450 g/hm2 of the active ingredient and 45 days after field application, the fresh weight control effect of pentoxazone on weeds in direct seeding paddy fields was 87.94%. The results showed that pentoxazone has good application prospects in direct-seeding rice fields.
In order to explore the application technology of pentoxazone in direct-seeding rice fields, the control spectrum, biological activity, and safety of pentoxazone to eight varieties of rice were determined in the greenhouse, and its control efficacy in the field was verified. The results showed that when the dose of the active ingredient was 225 g/hm2, the inhibition rates of pentoxazone on fresh weight of five kinds of weeds including Eleusine indica, Cyperus difformis, Eclipta prostrata, Cyperus rotundus, and Cyperus iria were all more than 90%, and the GR50 (active ingredient, the same as the rest) of pentoxazone on main weeds such as Echinochloa crus-galli, Digitaria sanguinalis, E. prostrate, and C. iria were between 82.15 g/hm2 and 189.17 g/hm2. The safety results showed that when the dose of the active ingredient was 1800 g/hm2, it was safe for the eight tested rice varieties, with plant height inhibition rates of 1.89%-5.16%, and fresh weight inhibition rates of 1.47%-4.14%. The selectivity indexes of pentoxazone between four rice varieties Longliangyouhuazhan, Ziliangyou 5, Nanjing 9108, Nanjing 46, and four weeds E. crus-galli, D. sanguinalis, E. prostrate, C. iria were 3.27-28.24, and its selectivities between rice and E. prostrate, and C. iria were significantly better than that of oxydiazon. At 450 g/hm2 of the active ingredient and 45 days after field application, the fresh weight control effect of pentoxazone on weeds in direct seeding paddy fields was 87.94%. The results showed that pentoxazone has good application prospects in direct-seeding rice fields.
2023, 25(1): 126-131.
doi: 10.16801/j.issn.1008-7303.2022.0126
Abstract:
Benzobicyclon is a 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicide that was registered in Chinese rice production. It has a wide herbicidal spectrum, especially good control efficacy on malignant weeds such as resistant Chinese sprangletop (Leptochloa chinensis), weedy rice (Oryza sativa f. spontanea), and so on. In order to explore the application prospect and technology of benzobicyclon in the direct seeding rice field, the safety evaluation of benzobicyclon 25% SC on various rice varieties at different leaf stages was studied by the pot-culture experiment. The results showed that: Under whether the condition of shallow water at 1-2 leaf stage, 2-3 leaf stage, and 3-4 leaf stage of rice, or the wet condition at the 1-2 leaf stage of rice, the application of 150-375 g a.i./hm2 of benzobicyclon 25% SC was safe to the three conventional Japonica varieties Nanjing 46, Huruan1212, Songxiangjing1018 and the hybrid Japonica varieties Shenyou 26, which were mainly planted in Shanghai, and had no significant effect on the growth indices including plant height, aboveground fresh weight, root length, and root fresh weight. The results indicate that benzobicyclon is safe for Japonica rice varieties, and is expected to become an excellent herbicide variety in the direct seeding rice fields with the updated application technology.
Benzobicyclon is a 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicide that was registered in Chinese rice production. It has a wide herbicidal spectrum, especially good control efficacy on malignant weeds such as resistant Chinese sprangletop (Leptochloa chinensis), weedy rice (Oryza sativa f. spontanea), and so on. In order to explore the application prospect and technology of benzobicyclon in the direct seeding rice field, the safety evaluation of benzobicyclon 25% SC on various rice varieties at different leaf stages was studied by the pot-culture experiment. The results showed that: Under whether the condition of shallow water at 1-2 leaf stage, 2-3 leaf stage, and 3-4 leaf stage of rice, or the wet condition at the 1-2 leaf stage of rice, the application of 150-375 g a.i./hm2 of benzobicyclon 25% SC was safe to the three conventional Japonica varieties Nanjing 46, Huruan1212, Songxiangjing1018 and the hybrid Japonica varieties Shenyou 26, which were mainly planted in Shanghai, and had no significant effect on the growth indices including plant height, aboveground fresh weight, root length, and root fresh weight. The results indicate that benzobicyclon is safe for Japonica rice varieties, and is expected to become an excellent herbicide variety in the direct seeding rice fields with the updated application technology.
2023, 25(1): 132-139.
doi: 10.16801/j.issn.1008-7303.2022.0147
Abstract:
In this study, Trichoderma asperellum TCS007, isolated from marine habitat, was evaluated for its ability to promote growth and induce stress tolerance in plants. Experiments were conducted to test the effects of TCS007 on seed germination, seedling and root growth, and the content of chlorophyll, soluble sugar and protein in cucumber and rice. In addition, the key physiological indicators of TCS007 treated and untreated cucumber and rice plants were measured under low temperature and high salt stresses. The results showed that 1 × 106 CFU/mL spore suspension of TCS007 significantly promoted cucumber seed germination. Plant fresh weight, leaf area, root fresh weight, and root activity of treated cucumber seedlings increased by 13.53%, 17.97%, 66.67%, and 27.30%, respectively. The contents of total chlorophyll, soluble sugar, and soluble protein increased by 22.75%, 18.24%, and 8.60%, respectively. The activities of peroxidase (POD) and superoxide dismutase (SOD) increased and malondialdehyde (MDA) and the relative conductivity (REC) content decreased in cucumber leaves treated with 1 × 106 CFU/mL spore suspension of TCS007 at 5 ℃, 10 ℃, and 15 ℃. Under 0.1 mol/L NaCl (high salt) stress, TCS007 significantly alleviated the salt damage to rice seedlings. The alleviating effect increased as the concentration of TCS007 spore suspension increased. The activities of POD, SOD, and catalase (CAT) were significantly increased, and REC was decreased in rice seedlings treated with 5% 1 × 106 CFU/mL TCS007 spore suspension. Overall, the study suggests T. asperellum TCS007 has positive effects on plant growth and stress tolerances and provides a theoretical basis for its development as a biopesticide.
In this study, Trichoderma asperellum TCS007, isolated from marine habitat, was evaluated for its ability to promote growth and induce stress tolerance in plants. Experiments were conducted to test the effects of TCS007 on seed germination, seedling and root growth, and the content of chlorophyll, soluble sugar and protein in cucumber and rice. In addition, the key physiological indicators of TCS007 treated and untreated cucumber and rice plants were measured under low temperature and high salt stresses. The results showed that 1 × 106 CFU/mL spore suspension of TCS007 significantly promoted cucumber seed germination. Plant fresh weight, leaf area, root fresh weight, and root activity of treated cucumber seedlings increased by 13.53%, 17.97%, 66.67%, and 27.30%, respectively. The contents of total chlorophyll, soluble sugar, and soluble protein increased by 22.75%, 18.24%, and 8.60%, respectively. The activities of peroxidase (POD) and superoxide dismutase (SOD) increased and malondialdehyde (MDA) and the relative conductivity (REC) content decreased in cucumber leaves treated with 1 × 106 CFU/mL spore suspension of TCS007 at 5 ℃, 10 ℃, and 15 ℃. Under 0.1 mol/L NaCl (high salt) stress, TCS007 significantly alleviated the salt damage to rice seedlings. The alleviating effect increased as the concentration of TCS007 spore suspension increased. The activities of POD, SOD, and catalase (CAT) were significantly increased, and REC was decreased in rice seedlings treated with 5% 1 × 106 CFU/mL TCS007 spore suspension. Overall, the study suggests T. asperellum TCS007 has positive effects on plant growth and stress tolerances and provides a theoretical basis for its development as a biopesticide.
2023, 25(1): 140-149.
doi: 10.16801/j.issn.1008-7303.2022.0081
Abstract:
Soilborne diseases such as potato Verticillium wilt and potato scab seriously affected the yield and quality of potato and no effective chemical is available to control the diseases. In this study, Bacillus subtilis HMB26553 and B. amyloliquefaciens PHODG36 were used as active ingredients to develop wettable powder (WP). After evaluating the doses of the wetting agent, dispersant, and UV protective agent, the optimal formulation of 3 billion CFU/g Bacillus WP was established as follows: 10% HMB26553 technical concentrate (TK), 10% PHODG36 TK, 1% wetting agent LT-569, 2% dispersant MF, 1% UV protective agent ascorbic acid, talc powder 76%. The spore content of the WP was up to 3.76 billion CFU/g; the rate of mixed bacteria was 2.8%; the pH value was 7.8; the fineness was 98.2%; the drying loss was 1.6%; the wetting time was 95.7 s; and the suspension rate was 80.7%. Pot experiment showed that seed-dressing with 15 to 45 kg/hm2 of the WP was safe on potato seedling emergence, and had no adverse effects on potato growth. The control effect on potato Verticillium wilt ranged from 45.1% to 47.4%. Field plot experiments demonstrated that treatments with 15 to 45 kg/hm2 of WP could significantly reduce the occurrence of potato scab, the control efficacy was 72.0% and the yield increase rate was 15.5% of treatment with 30 kg/hm2 WP. Field trial demonstrations in different regions showed that the control efficacy of potato Verticillium wilt and potato scab was 50.8% to 62.1%, and 63.9% to 65.7%, respectively, with the treatment of 30 kg/hm2 WP. Meanwhile, potato yields increased from 14.3% to 29.4%. The results indicated that 3 billion CFU/g Bacillus WP could effectively control potato soil-borne diseases, and significantly increase potato yield, providing a basis for the extensive application of WP in potato production.
Soilborne diseases such as potato Verticillium wilt and potato scab seriously affected the yield and quality of potato and no effective chemical is available to control the diseases. In this study, Bacillus subtilis HMB26553 and B. amyloliquefaciens PHODG36 were used as active ingredients to develop wettable powder (WP). After evaluating the doses of the wetting agent, dispersant, and UV protective agent, the optimal formulation of 3 billion CFU/g Bacillus WP was established as follows: 10% HMB26553 technical concentrate (TK), 10% PHODG36 TK, 1% wetting agent LT-569, 2% dispersant MF, 1% UV protective agent ascorbic acid, talc powder 76%. The spore content of the WP was up to 3.76 billion CFU/g; the rate of mixed bacteria was 2.8%; the pH value was 7.8; the fineness was 98.2%; the drying loss was 1.6%; the wetting time was 95.7 s; and the suspension rate was 80.7%. Pot experiment showed that seed-dressing with 15 to 45 kg/hm2 of the WP was safe on potato seedling emergence, and had no adverse effects on potato growth. The control effect on potato Verticillium wilt ranged from 45.1% to 47.4%. Field plot experiments demonstrated that treatments with 15 to 45 kg/hm2 of WP could significantly reduce the occurrence of potato scab, the control efficacy was 72.0% and the yield increase rate was 15.5% of treatment with 30 kg/hm2 WP. Field trial demonstrations in different regions showed that the control efficacy of potato Verticillium wilt and potato scab was 50.8% to 62.1%, and 63.9% to 65.7%, respectively, with the treatment of 30 kg/hm2 WP. Meanwhile, potato yields increased from 14.3% to 29.4%. The results indicated that 3 billion CFU/g Bacillus WP could effectively control potato soil-borne diseases, and significantly increase potato yield, providing a basis for the extensive application of WP in potato production.
2023, 25(1): 150-157.
doi: 10.16801/j.issn.1008-7303.2022.0118
Abstract:
In order to clarify the important role of spray adjuvants in the chemical control of apple orchard, the effects of three spray adjuvants GY-T12, NF-100 and Mairun on the physicochemical properties, wettability and retention of sulfoxaflor 22% SC were evaluated at CMC by measuring the surface tension, the contact angle and the maximum retention, and the synergistic effects to Aphis citricola were investigated. The results showed that the addition of three spray adjuvants reduce the surface tension of solutions from 50.65 mN/m to 27.64-35.64 mN/m. According to the contact angle of water droplets on the surface of apple leaves, less or greater than 90°, the adaxial surface is judged as a hydrophilic surface and the abaxial surface was judged as a hydrophobic surface. The addition of adjuvants decreases 30 seconds static contact angles on the adaxial surface by 23.2°-41.3° and by 68.0°-93.5° on the abaxial surface. The wettability assay showed when the concentrations of three spray adjuvants reached CMC, the adhesion work decreased by 5.36-12.56 mJ/m2 while the adhesion tension increased by 9.27-11.26 mN/m between the droplets and the adaxial surface, the adhesion work and adhesion tension increased by 27.45-36.66 mJ/m2 and 47.55-53.28 mN/m between the droplets and the abaxial surface. Then, the regression equation between the maximum retention and surface tension was established, it showed that the maximum retention is 12.53 mg/cm2 when the surface tension is 40.89 mN/m. Among the three spray adjuvants, NF-100 and GY-T12 significantly increase the retention of pesticides, moreover, the synergistic effect of GY-T12 on A. citricola is notable. Therefore, the selection of spray adjuvants in apple orchards should macth the expected goals, and the proper adjuvant is feasible to regulate the surface tension of pesticide in an appropriate range to increase the retention and improve the toxicity to target pests.
In order to clarify the important role of spray adjuvants in the chemical control of apple orchard, the effects of three spray adjuvants GY-T12, NF-100 and Mairun on the physicochemical properties, wettability and retention of sulfoxaflor 22% SC were evaluated at CMC by measuring the surface tension, the contact angle and the maximum retention, and the synergistic effects to Aphis citricola were investigated. The results showed that the addition of three spray adjuvants reduce the surface tension of solutions from 50.65 mN/m to 27.64-35.64 mN/m. According to the contact angle of water droplets on the surface of apple leaves, less or greater than 90°, the adaxial surface is judged as a hydrophilic surface and the abaxial surface was judged as a hydrophobic surface. The addition of adjuvants decreases 30 seconds static contact angles on the adaxial surface by 23.2°-41.3° and by 68.0°-93.5° on the abaxial surface. The wettability assay showed when the concentrations of three spray adjuvants reached CMC, the adhesion work decreased by 5.36-12.56 mJ/m2 while the adhesion tension increased by 9.27-11.26 mN/m between the droplets and the adaxial surface, the adhesion work and adhesion tension increased by 27.45-36.66 mJ/m2 and 47.55-53.28 mN/m between the droplets and the abaxial surface. Then, the regression equation between the maximum retention and surface tension was established, it showed that the maximum retention is 12.53 mg/cm2 when the surface tension is 40.89 mN/m. Among the three spray adjuvants, NF-100 and GY-T12 significantly increase the retention of pesticides, moreover, the synergistic effect of GY-T12 on A. citricola is notable. Therefore, the selection of spray adjuvants in apple orchards should macth the expected goals, and the proper adjuvant is feasible to regulate the surface tension of pesticide in an appropriate range to increase the retention and improve the toxicity to target pests.
2023, 25(1): 158-166.
doi: 10.16801/j.issn.1008-7303.2022.0123
Abstract:
To improve the control efficacy of Bacillus amyloliquefaciens Lx-11 suspension concentrate on rice bacterial blight, four kinds of spray adjuvants (silicone, TM-10, lecithin, and SY-6535) were selected in this study and their effects on B. amyloliquefaciens Lx-11 bacterial content, the liquid's surface tension, contact angle changes, and the safety of rice growth were evaluated. In addition, the control effect of Lx-11 strain against bacterial blight in the pot experiment and the colonization dynamics on rice leaf surface were determined for an applicable spray adjuvant. The results showed that the bacterial content of B. amyloliquefaciens Lx-11 is significantly declining when treated with lecithin among four spray adjuvants. Silicone, TM-10, and SY-6535 effectively reduce the surface tension of the suspension solution and the contact angle on rice leaves. The safety evaluation of rice showed that silicone, TM-10, and SY-6535 does not affect the growth of rice seedlings. The pot experiment results showed that the control efficacy of biocontrol bacteria Lx-11 (4.0 × 109 cfu/mL) against bacterial blight reaches 57.70% and 56.56% after adding TM-10 and SY-6535, which was significantly higher than that of the suspension agent without adjuvants. The colonization experiment showed that the colonization of Lx-11 strain on the rice leaf surface is significantly higher after adding adjuvants than that of the control treatment.
To improve the control efficacy of Bacillus amyloliquefaciens Lx-11 suspension concentrate on rice bacterial blight, four kinds of spray adjuvants (silicone, TM-10, lecithin, and SY-6535) were selected in this study and their effects on B. amyloliquefaciens Lx-11 bacterial content, the liquid's surface tension, contact angle changes, and the safety of rice growth were evaluated. In addition, the control effect of Lx-11 strain against bacterial blight in the pot experiment and the colonization dynamics on rice leaf surface were determined for an applicable spray adjuvant. The results showed that the bacterial content of B. amyloliquefaciens Lx-11 is significantly declining when treated with lecithin among four spray adjuvants. Silicone, TM-10, and SY-6535 effectively reduce the surface tension of the suspension solution and the contact angle on rice leaves. The safety evaluation of rice showed that silicone, TM-10, and SY-6535 does not affect the growth of rice seedlings. The pot experiment results showed that the control efficacy of biocontrol bacteria Lx-11 (4.0 × 109 cfu/mL) against bacterial blight reaches 57.70% and 56.56% after adding TM-10 and SY-6535, which was significantly higher than that of the suspension agent without adjuvants. The colonization experiment showed that the colonization of Lx-11 strain on the rice leaf surface is significantly higher after adding adjuvants than that of the control treatment.
2023, 25(1): 167-174.
doi: 10.16801/j.issn.1008-7303.2022.0075
Abstract:
At present, zineb has not been registered on edible lily in China, and the lack of pre-harvest intervals and other relative information may lead to irrational use of pesticides and high residue risks. In order to determine the residue risks of zineb on edible lily, the residue dissipation and dietary risks of zineb residues were evaluated in field trials. The results showed that the degradation of zineb in lily conformed to the first-order kinetic equation, and the half-lives in Jiangsu and Hunan Provinces were 5.9 and 3.8 days, respectively. To investigate the terminal residues in the field trial, the recommended dosage (3000 g a.i./hm2) and 1.5 times recommended dosage (4500 g a.i./hm2) of 65% zineb wettable powder were sprayed three or four times on lily crops at four locations. At 7, 14 and 21 days after the last application, the maximum residues of zineb (calculated by CS2) in harvested fresh lily and dried lily were 0.260 mg/kg and 1.290 mg/kg, respectively, both of which were lower than the maximum residue limits (MRL) of zineb in China on fresh lily (0.5 mg/kg) and dried lily (2 mg/kg). Because zineb is easily degraded to ethylene thiourea (ETU), and the ETU was detected in the samples of fresh lily, the dietary intake risks of zineb and its metabolite ETU in lily were analyzed. The results of the dietary risk assessment suggested that the ratios of dietary intake risk of zineb to the acceptable daily intake (ADI) in fresh and dried lilies were 0.014% and < 0.014%, respectively, which contributed very little to the overall dietary exposure. These results showed that the residues of Zineb in edible lily would not have an unacceptable risk to Chinese people when Zineb formulation was applied at the recommended dose.
At present, zineb has not been registered on edible lily in China, and the lack of pre-harvest intervals and other relative information may lead to irrational use of pesticides and high residue risks. In order to determine the residue risks of zineb on edible lily, the residue dissipation and dietary risks of zineb residues were evaluated in field trials. The results showed that the degradation of zineb in lily conformed to the first-order kinetic equation, and the half-lives in Jiangsu and Hunan Provinces were 5.9 and 3.8 days, respectively. To investigate the terminal residues in the field trial, the recommended dosage (3000 g a.i./hm2) and 1.5 times recommended dosage (4500 g a.i./hm2) of 65% zineb wettable powder were sprayed three or four times on lily crops at four locations. At 7, 14 and 21 days after the last application, the maximum residues of zineb (calculated by CS2) in harvested fresh lily and dried lily were 0.260 mg/kg and 1.290 mg/kg, respectively, both of which were lower than the maximum residue limits (MRL) of zineb in China on fresh lily (0.5 mg/kg) and dried lily (2 mg/kg). Because zineb is easily degraded to ethylene thiourea (ETU), and the ETU was detected in the samples of fresh lily, the dietary intake risks of zineb and its metabolite ETU in lily were analyzed. The results of the dietary risk assessment suggested that the ratios of dietary intake risk of zineb to the acceptable daily intake (ADI) in fresh and dried lilies were 0.014% and < 0.014%, respectively, which contributed very little to the overall dietary exposure. These results showed that the residues of Zineb in edible lily would not have an unacceptable risk to Chinese people when Zineb formulation was applied at the recommended dose.
2023, 25(1): 175-183.
doi: 10.16801/j.issn.1008-7303.2022.0146
Abstract:
The spraying of fungicides on mangoes near harvest time to reduce occurrence of diseases could result in the pesticide residues in harvested products. To explore the potential health risk for subgroups in China, a residue analytical method was developed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for simultaneous determination of 13 strobilurin and triazole fungicides in mango. Based on the residue data, the long-term and short-term dietary exposure risk assessment to adults and children in China was conducted by "point estimates" method. The linearity of 13 fungicides was excellent in the range of 1-100 μg/L, with the coefficients of determination (R2) above 0.9994. The limit of quantification (LOQ) was 5 μg/kg. The average recoveries were 76%-122% at 5 spiked levels, with the relative standard deviation (RSD) of 0.7%-14%. The residue results of the mango samples from the main producing areas and consumer cities in China indicated that the fungicides with high detection rates were pyraclostrobin (22.6%), azoxystrobin (18.5%) and difenoconazole (15.5%). The 50th and 97.5th percentile residue levels were used to calculate the contribution rate of the fungicides to the long-term and short-term dietary intake risks, respectively. The results demonstrated that the contribution rates of 13 fungicides in mango to the long-term dietary risk of adults and children were 0.01%-0.5% and 0.01%-0.3%, respectively. For the short-term assessment, the dietary exposure risks of the 9 fungicides that have acute reference dose (ARfD) were acceptable with risk quotients (RQs) of 0.02%-28.9% for children and 0.01%-7.2% for adults. From the risk assessment results, it could be concluded that long-term and short-term exposure of 13 fungicides in mangoes would not cause a health concern for general population. According to the registration status of the 13 pesticides, the MRLs in national standards of China (GB 2763—2021), and the results of dietary exposure assessment of the 13 fungicides, it is recommended to strengthen the supervision on application of 7 unregistered pesticides on mangoes, including kresoxim-methyl, propiconazole, myclobutanil, flusilazole, fenbuconazole, epoxiconazole and triadimenol, and to modify the MRL of pyraclostrobin and to set a MRL for picoxystrobin in mangoes.
The spraying of fungicides on mangoes near harvest time to reduce occurrence of diseases could result in the pesticide residues in harvested products. To explore the potential health risk for subgroups in China, a residue analytical method was developed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for simultaneous determination of 13 strobilurin and triazole fungicides in mango. Based on the residue data, the long-term and short-term dietary exposure risk assessment to adults and children in China was conducted by "point estimates" method. The linearity of 13 fungicides was excellent in the range of 1-100 μg/L, with the coefficients of determination (R2) above 0.9994. The limit of quantification (LOQ) was 5 μg/kg. The average recoveries were 76%-122% at 5 spiked levels, with the relative standard deviation (RSD) of 0.7%-14%. The residue results of the mango samples from the main producing areas and consumer cities in China indicated that the fungicides with high detection rates were pyraclostrobin (22.6%), azoxystrobin (18.5%) and difenoconazole (15.5%). The 50th and 97.5th percentile residue levels were used to calculate the contribution rate of the fungicides to the long-term and short-term dietary intake risks, respectively. The results demonstrated that the contribution rates of 13 fungicides in mango to the long-term dietary risk of adults and children were 0.01%-0.5% and 0.01%-0.3%, respectively. For the short-term assessment, the dietary exposure risks of the 9 fungicides that have acute reference dose (ARfD) were acceptable with risk quotients (RQs) of 0.02%-28.9% for children and 0.01%-7.2% for adults. From the risk assessment results, it could be concluded that long-term and short-term exposure of 13 fungicides in mangoes would not cause a health concern for general population. According to the registration status of the 13 pesticides, the MRLs in national standards of China (GB 2763—2021), and the results of dietary exposure assessment of the 13 fungicides, it is recommended to strengthen the supervision on application of 7 unregistered pesticides on mangoes, including kresoxim-methyl, propiconazole, myclobutanil, flusilazole, fenbuconazole, epoxiconazole and triadimenol, and to modify the MRL of pyraclostrobin and to set a MRL for picoxystrobin in mangoes.
2023, 25(1): 184-192.
doi: 10.16801/j.issn.1008-7303.2022.0073
Abstract:
To evaluate the dietary exposure risk of pyraclostrobin and tebuconazole in peach, supervised residue trials were carried out in eight typical regions, and the terminal residues of the two pesticides at harvest period were studied. A method for residue analysis of pyraclostrobin and tebuconazole in peach was revised and developed using high performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-MS/MS). The results showed that there was a good linear relationship between the concentration and peak area of pyraclostrobin and tebuconazole in the range of 0.01-4.0 mg/L (R2≥0.9906). At the spiking levels of 0.01-4.0 mg/kg, the recoveries of pyraclostrobin were 88%-92% with the relative standard deviations (RSDs) of 5.6%-18.7%, and the recoveries of tebuconazole were 96%-106% with the RSDs of 0.8%-13.2%. The half-lives of pyraclostrobin and tebuconazole in peach fruits were 7.3-13.9 d and 5.4-8.9 d, respectively. The supervised trial median residues (STMR) of pyraclostrobin and tebuconazole in whole fruit of peach were 0.037 and 0.053 mg/kg, and the highest residues (HR) were 0.16 and 0.24 mg/kg, respectively. At 28 d after the last application, the contribution (RQc) of residues of pyraclostrobin and tebuconazole in peaches to the risk quotient (RQ) were 0.02% and 0.03%,respectively, which indicated that the chronic dietary exposure risk of pyraclostrobin and tebuconazole in peach to the general population in China was very low. For the short-term dietary exposure risk assessment, the national estimated short-term intake (NESTI) of pyraclostrobin and tebuconazole accounted for 0.4% and 2% of the acute reference dose (ARfD) respectively, and it was 2% and 4% for children aged 1-6 years, which indicated that the acute exposure risk was also at an acceptable level. Overall, based on the supervised residue trials and the long-term and short-term dietary exposure risk analysis, it could be considered that pyraclostrobin and tebuconazole are safe to be applied strictly in accordance with the Good Agricultural Practices and label recommendations on peach trees.
To evaluate the dietary exposure risk of pyraclostrobin and tebuconazole in peach, supervised residue trials were carried out in eight typical regions, and the terminal residues of the two pesticides at harvest period were studied. A method for residue analysis of pyraclostrobin and tebuconazole in peach was revised and developed using high performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-MS/MS). The results showed that there was a good linear relationship between the concentration and peak area of pyraclostrobin and tebuconazole in the range of 0.01-4.0 mg/L (R2≥0.9906). At the spiking levels of 0.01-4.0 mg/kg, the recoveries of pyraclostrobin were 88%-92% with the relative standard deviations (RSDs) of 5.6%-18.7%, and the recoveries of tebuconazole were 96%-106% with the RSDs of 0.8%-13.2%. The half-lives of pyraclostrobin and tebuconazole in peach fruits were 7.3-13.9 d and 5.4-8.9 d, respectively. The supervised trial median residues (STMR) of pyraclostrobin and tebuconazole in whole fruit of peach were 0.037 and 0.053 mg/kg, and the highest residues (HR) were 0.16 and 0.24 mg/kg, respectively. At 28 d after the last application, the contribution (RQc) of residues of pyraclostrobin and tebuconazole in peaches to the risk quotient (RQ) were 0.02% and 0.03%,respectively, which indicated that the chronic dietary exposure risk of pyraclostrobin and tebuconazole in peach to the general population in China was very low. For the short-term dietary exposure risk assessment, the national estimated short-term intake (NESTI) of pyraclostrobin and tebuconazole accounted for 0.4% and 2% of the acute reference dose (ARfD) respectively, and it was 2% and 4% for children aged 1-6 years, which indicated that the acute exposure risk was also at an acceptable level. Overall, based on the supervised residue trials and the long-term and short-term dietary exposure risk analysis, it could be considered that pyraclostrobin and tebuconazole are safe to be applied strictly in accordance with the Good Agricultural Practices and label recommendations on peach trees.
2023, 25(1): 193-209.
doi: 10.16801/j.issn.1008-7303.2022.0141
Abstract:
A gas-chromatography-tandem mass spectrometry (GC-MS/MS) method was established for simultaneous determination of 99 pesticide residues in four matrices, including dried red dates, apricots, grapes and pears. Samples were extracted with acetonitrile, salted out by sodium chloride, and centrifuged. The supernatant was purified by dispersive solid phase extraction (d-SPE), concentrated and dissolved in acetone to volume, and determined by GC-MS/MS. Three cleanup approaches were compared, including solid phase extraction (SPE) with Carb/NH2 SPE column, dispersive solid phase extraction (d-SPE) with NH2 + C18 + GCB, and d-SPE with primary-secondary amine (PSA) + C18 + GCB. The results showed that d-SPE with PSA + C18 + GCB were favorable than the other two approaches. Applying the optimized method, targeted compounds were quantified by the matrix-matched external standard calibration method. The calibration curves in four matrices were in the range of 0.005-0.5 mg/L with good coefficient (R2 ≥ 0.9915), and the limits of quantification (LOQs) ranged from 0.01 to 0.025 mg/kg. At four spiked levels of 0.01, 0.025, 0.05, and 0.1 mg/kg, the average recoveries of 95 pesticides (96% of total) were 70%-120% and the relative standard deviations (RSD) were 0.3%-20%. The method is simple and efficient, and the sensitivity, accuracy, and precision can meet the routine testing requirements. It is suitable for the simultaneous determination of multiple pesticide residues in the above four fruit matrices.
A gas-chromatography-tandem mass spectrometry (GC-MS/MS) method was established for simultaneous determination of 99 pesticide residues in four matrices, including dried red dates, apricots, grapes and pears. Samples were extracted with acetonitrile, salted out by sodium chloride, and centrifuged. The supernatant was purified by dispersive solid phase extraction (d-SPE), concentrated and dissolved in acetone to volume, and determined by GC-MS/MS. Three cleanup approaches were compared, including solid phase extraction (SPE) with Carb/NH2 SPE column, dispersive solid phase extraction (d-SPE) with NH2 + C18 + GCB, and d-SPE with primary-secondary amine (PSA) + C18 + GCB. The results showed that d-SPE with PSA + C18 + GCB were favorable than the other two approaches. Applying the optimized method, targeted compounds were quantified by the matrix-matched external standard calibration method. The calibration curves in four matrices were in the range of 0.005-0.5 mg/L with good coefficient (R2 ≥ 0.9915), and the limits of quantification (LOQs) ranged from 0.01 to 0.025 mg/kg. At four spiked levels of 0.01, 0.025, 0.05, and 0.1 mg/kg, the average recoveries of 95 pesticides (96% of total) were 70%-120% and the relative standard deviations (RSD) were 0.3%-20%. The method is simple and efficient, and the sensitivity, accuracy, and precision can meet the routine testing requirements. It is suitable for the simultaneous determination of multiple pesticide residues in the above four fruit matrices.
2023, 25(1): 210-219.
doi: 10.16801/j.issn.1008-7303.2022.0085
Abstract:
A rapid screening method for 173 pesticides in onion was established using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF/MS). Onion samples were extracted with 1% acetic acid in acetonitrile, salted out, shaken and centrifuged, then cleaned-up by SPE column with Carb/NH2. The LC-QTOF/MS detection was operated in the positive ion all ions MS/MS scanning mode of electrospray ionization. The important parameters such as maximum number of characteristic ions, co-elution score and peak height threshold were optimized for the qualitative screening, and the final screening parameters were determined for analysis of the collected results. Meanwhile, the methodological parameters of 173 pesticides in onion were investigated. The results showed that the SDL and LOQ of 167 pesticides were 0.001-0.005 mg/kg and 0.001-0.01 mg/kg, respectively, and it was 0.01-0.025 mg/kg and 0.02-0.05 mg/kg for the remaining 6 pesticides. These pesticides had good linear relationship in the test concentration range. The results of the recovery experiments showed that the average recoveries (n=5) of 153, 168 and 165 pesticides at three different levels (1 × LOQ, 2 × LOQ, 10 × LOQ) were in the range of 70%-120%, respectively, and the RSDs were all within 20%. The established screening method was applied to the proficiency test of pesticide residues in fruits and vegetables organized by the European Union in 2020 (EUPT-FV22). The pesticides spiked in onion were accurately screened, and the quantitative results were satisfactory. The results show that the LC-QTOF/MS screening method established in this work is accurate and reliable, and is suitable for rapid screening and accurate quantification of multi-pesticide residues in onion.
A rapid screening method for 173 pesticides in onion was established using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF/MS). Onion samples were extracted with 1% acetic acid in acetonitrile, salted out, shaken and centrifuged, then cleaned-up by SPE column with Carb/NH2. The LC-QTOF/MS detection was operated in the positive ion all ions MS/MS scanning mode of electrospray ionization. The important parameters such as maximum number of characteristic ions, co-elution score and peak height threshold were optimized for the qualitative screening, and the final screening parameters were determined for analysis of the collected results. Meanwhile, the methodological parameters of 173 pesticides in onion were investigated. The results showed that the SDL and LOQ of 167 pesticides were 0.001-0.005 mg/kg and 0.001-0.01 mg/kg, respectively, and it was 0.01-0.025 mg/kg and 0.02-0.05 mg/kg for the remaining 6 pesticides. These pesticides had good linear relationship in the test concentration range. The results of the recovery experiments showed that the average recoveries (n=5) of 153, 168 and 165 pesticides at three different levels (1 × LOQ, 2 × LOQ, 10 × LOQ) were in the range of 70%-120%, respectively, and the RSDs were all within 20%. The established screening method was applied to the proficiency test of pesticide residues in fruits and vegetables organized by the European Union in 2020 (EUPT-FV22). The pesticides spiked in onion were accurately screened, and the quantitative results were satisfactory. The results show that the LC-QTOF/MS screening method established in this work is accurate and reliable, and is suitable for rapid screening and accurate quantification of multi-pesticide residues in onion.
2023, 25(1): 220-226.
doi: 10.16801/j.issn.1008-7303.2022.0095
Abstract:
A residue analytical method of trifloxystrobin in zebrafish was established by PRiME HLB solid-phase extraction coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Based on the established method, the bioaccumulation effect of trifloxystrobin on zebrafish was estimated. The results showed that the calibration curves for trifloxystrobin was linear in the range of 0.0001-0.05 mg/L. At fortified levels of 0.0005 and 0.05 mg/L, the average recoveries of trifloxystrobin in water ranged from 86.6% to 106% with relative standard deviations (RSDs) of 5.1%-8.9%. The average recoveries in fish were 70.5%-104%, with RSDs of 1.4%-3.3% at the fortified levels of 0.01, 0.1 and 10 mg/kg. The limit of quantification (LOQ) of trifloxystrobin in water and fish was 0.0005 mg/L and 0.01 mg/kg, respectively. Based on the aquatic life benchmark (ALB) of acute toxic to fish and the LC50 value of zebrafish, the bioaccumulation effect of trifloxystrobin on zebrafish was studied at six exposure doses, which included the 1/10 ALB (7.15 × 10−4 mg/L), ALB (7.15 × 10−3 mg/L), the 1/100 LC50 (5.10 × 10−4, 1.20 × 10−3 mg/L), and 1/10 LC50 (5.10 × 10−3, 1.20 × 10−2 mg/L). After continuous exposure for 192 h, the bioconcentration factor (BCF) of trifloxystrobin ranged from 113 to 178 at different exposure doses, suggested that trifloxystrobin had a medium bioconcentration effect on zebrafish. The results indicated that in the process of application of trifloxystrobin, the ecotoxicological risk caused by the bioaccumulation effect of low concentration exposure of trifloxystrobin on aquatic species should be considered.
A residue analytical method of trifloxystrobin in zebrafish was established by PRiME HLB solid-phase extraction coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Based on the established method, the bioaccumulation effect of trifloxystrobin on zebrafish was estimated. The results showed that the calibration curves for trifloxystrobin was linear in the range of 0.0001-0.05 mg/L. At fortified levels of 0.0005 and 0.05 mg/L, the average recoveries of trifloxystrobin in water ranged from 86.6% to 106% with relative standard deviations (RSDs) of 5.1%-8.9%. The average recoveries in fish were 70.5%-104%, with RSDs of 1.4%-3.3% at the fortified levels of 0.01, 0.1 and 10 mg/kg. The limit of quantification (LOQ) of trifloxystrobin in water and fish was 0.0005 mg/L and 0.01 mg/kg, respectively. Based on the aquatic life benchmark (ALB) of acute toxic to fish and the LC50 value of zebrafish, the bioaccumulation effect of trifloxystrobin on zebrafish was studied at six exposure doses, which included the 1/10 ALB (7.15 × 10−4 mg/L), ALB (7.15 × 10−3 mg/L), the 1/100 LC50 (5.10 × 10−4, 1.20 × 10−3 mg/L), and 1/10 LC50 (5.10 × 10−3, 1.20 × 10−2 mg/L). After continuous exposure for 192 h, the bioconcentration factor (BCF) of trifloxystrobin ranged from 113 to 178 at different exposure doses, suggested that trifloxystrobin had a medium bioconcentration effect on zebrafish. The results indicated that in the process of application of trifloxystrobin, the ecotoxicological risk caused by the bioaccumulation effect of low concentration exposure of trifloxystrobin on aquatic species should be considered.
2023, 25(1): 227-236.
doi: 10.16801/j.issn.1008-7303.2022.0096
Abstract:
In order to find out the distribution characteristics of heavy metals in pesticides and the cumulative risk of heavy metals in soil and vegetables after pesticide application, 54 commonly used pesticide formulations were collected from the market, and the field experiments were conducted to investigate the contents of heavy metals in different pesticide formulations and their safety risks after application. The results showed that heavy metal was common in pesticide formulations, and the average contents of Cr, As, Cd, Hg and Pb were 21.2, 3.23, 0.78, 0.85 and 3.43 mg/kg, respectively. The average contents of Cu and Zn in non Cu/Zn pesticides were 9.22 and 18.1 mg/kg, respectively. Three to seven heavy metals were detected in each pesticide. Relatively high content of Zn was detected in pesticide formulations containing Cu, while high contents of Cu and Cd were detected in Zn-containing pesticides. The results of correlation analysis showed that the contents of Zn-Cd, Cr-Pb-As and Hg-As in pesticide formulations were significantly correlated and their sources were homologous. In the year of pesticide use, the contents of heavy metals in soil increased by 5.74 × 10−8 mg/kg to 5.46 × 10−5 mg/kg. Compared to the application of other types of pesticides, the increment of Cr, As and Hg in soil was significantly higher after the application of insecticides, and the increment of Cu, Zn and Cd in soil was significantly higher after the application of fungicides. Nevertheless, according to the soil environmental quality standard in the National Standard of China (GB15618—2018), the annual accumulation of heavy metals in soil caused by pesticides application was negligible. In comparison with the blank control that no pesticide was sprayed, the application of thiosen copper for 5 times significantly increased the content of Pb in cabbage, and the application of propineb for 3 and 5 times significantly increased the content of Cd in cabbage, but neither Cd nor Pb exceeded the national limit. The maximum contents of Cd and Pb in cabbage were about 20% and 10% of the national limit value, respectively, suggesting that the risk was low.
In order to find out the distribution characteristics of heavy metals in pesticides and the cumulative risk of heavy metals in soil and vegetables after pesticide application, 54 commonly used pesticide formulations were collected from the market, and the field experiments were conducted to investigate the contents of heavy metals in different pesticide formulations and their safety risks after application. The results showed that heavy metal was common in pesticide formulations, and the average contents of Cr, As, Cd, Hg and Pb were 21.2, 3.23, 0.78, 0.85 and 3.43 mg/kg, respectively. The average contents of Cu and Zn in non Cu/Zn pesticides were 9.22 and 18.1 mg/kg, respectively. Three to seven heavy metals were detected in each pesticide. Relatively high content of Zn was detected in pesticide formulations containing Cu, while high contents of Cu and Cd were detected in Zn-containing pesticides. The results of correlation analysis showed that the contents of Zn-Cd, Cr-Pb-As and Hg-As in pesticide formulations were significantly correlated and their sources were homologous. In the year of pesticide use, the contents of heavy metals in soil increased by 5.74 × 10−8 mg/kg to 5.46 × 10−5 mg/kg. Compared to the application of other types of pesticides, the increment of Cr, As and Hg in soil was significantly higher after the application of insecticides, and the increment of Cu, Zn and Cd in soil was significantly higher after the application of fungicides. Nevertheless, according to the soil environmental quality standard in the National Standard of China (GB15618—2018), the annual accumulation of heavy metals in soil caused by pesticides application was negligible. In comparison with the blank control that no pesticide was sprayed, the application of thiosen copper for 5 times significantly increased the content of Pb in cabbage, and the application of propineb for 3 and 5 times significantly increased the content of Cd in cabbage, but neither Cd nor Pb exceeded the national limit. The maximum contents of Cd and Pb in cabbage were about 20% and 10% of the national limit value, respectively, suggesting that the risk was low.
2023, 25(1): 237-244.
doi: 10.16801/j.issn.1008-7303.2022.0137
Abstract:
In order to study the adsorption-desorption characteristics of triflumezopyrim in soil, The adsorption- desorption behavior of triflumezopyrim in five soils was studied using batch equilibrium method, and the effects of the environmental factors such as temperature and pH on the adsorption properties of triflumezopyrim were studied. The results showed that the adsorption kinetics of triflumezopyrim in soil was in accordance with the Elovich kinetics model, and the adsorption and desorption isotherms could be well fitted by Freundlich models. The adsorption constants ranged from 1.886 to 7.626. The increase of temperature was more conducive to adsorption, and the adsorption of triflumezopyrim in soil was mainly physical adsorption. With the increase of pH value in the solution, the adsorption capacity of soils to triflumezopyrim decreased gradually. Except that in the clay loam soil in Nanning City(S4), it showed a desorption hysteresis of triflumezopyrim in the five different soils, which indicated that triflumezopyrim is not easy to accumulate in the soil for a long term and has certain migration characteristics.
In order to study the adsorption-desorption characteristics of triflumezopyrim in soil, The adsorption- desorption behavior of triflumezopyrim in five soils was studied using batch equilibrium method, and the effects of the environmental factors such as temperature and pH on the adsorption properties of triflumezopyrim were studied. The results showed that the adsorption kinetics of triflumezopyrim in soil was in accordance with the Elovich kinetics model, and the adsorption and desorption isotherms could be well fitted by Freundlich models. The adsorption constants ranged from 1.886 to 7.626. The increase of temperature was more conducive to adsorption, and the adsorption of triflumezopyrim in soil was mainly physical adsorption. With the increase of pH value in the solution, the adsorption capacity of soils to triflumezopyrim decreased gradually. Except that in the clay loam soil in Nanning City(S4), it showed a desorption hysteresis of triflumezopyrim in the five different soils, which indicated that triflumezopyrim is not easy to accumulate in the soil for a long term and has certain migration characteristics.
2019, 21(5-6): 921-930.
doi: 10.16801/j.issn.1008-7303.2019.0089
2019, 21(4): 401-408.
doi: 10.16801/j.issn.1008-7303.2019.0072
2014, 16(5): 483-496.
doi: 10.3969/j.issn.1008-7303.2014.05.01
2015, 17(1): 1-14.
doi: 10.3969/j.issn.1008-7303.2015.01.01
2015, 17(1): 115-118.
doi: 10.3969/j.issn.1008-7303.2015.01.17
2016, 18(5): 545-555.
doi: 10.16801/j.issn.1008-7303.2016.0078
2019, 21(3): 327-337.
doi: 10.16801/j.issn.1008-7303.2019.0040
2014, 16(5): 497-507.
doi: 10.3969/j.issn.1008-7303.2014.05.02
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Journal Introduction
Superintendent：Ministry of Education of the People's Republic of China
Sponsor：China Agricultural University
Editor-in-Chief：ZHOU Zhiqiang
Deputy Editor-in-Chief：PAN Canping
Address：College of Science Room 340, China Agricultural University, No. 2, Yuanmingyuan West Road, Haidian, Beijing, China.
Postal Code：100193
Tel：86-010-62733003
E-mail：nyxuebao@263.net
ISSN：1008-7303
CN：11-3995/S
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