Laboratory mutants of Sclerotinia sclerotiorum(Lib)de Bary,resistant to boscalid,have been extensively characterized.However,the resistance situation in the lettuce field remains largely elusive.In this study,among th...Laboratory mutants of Sclerotinia sclerotiorum(Lib)de Bary,resistant to boscalid,have been extensively characterized.However,the resistance situation in the lettuce field remains largely elusive.In this study,among the 172 S.sclerotiorum isolates collected from asparagus lettuce field in Jiangsu Province,China,132 isolates(76.74%)exhibited low-level resistance to boscalid(Bos^(LR)),with a discriminatory dose of 5μg mL-1.In comparison to the boscalid-sensitive(BosS)isolates,most Bos^(LR)isolates demonstrated a slightly superior biological fitness,as evidenced by data on mycelial growth,sclerotium production and pathogenicity.Moreover,most Bos^(LR)isolates showed comparable levels of oxalic acid(OA)accumulation,increased exopolysaccharide(EPS)content and reduced membrane permeability when compared to the BosS isolates.Nevertheless,their responses to distinct stress factors diverged significantly.Furthermore,the effectiveness of boscalid in controlling Bos^(LR)isolates on radish was diminished compared to its efficacy on BosS isolates.Genetic mutations were identified in the SDH genes of Bos^(LR)isolates,revealing the existence of three resistant genotypes:I(^(A11V)at SDHB,SDHB^(A11V)),II(^(Q38R)at SDHC,SDHC^(Q38R))and III(SDHB^(A11V)+SDHC^(Q38R)).Importantly,no cross-resistance was observed between boscalid and other fungicides such as thifluzamide,pydiflumetofen,fluazinam,or tebuconazole.Our molecular docking analysis indicated that the docking total score(DTS)of the type I resistant isolates(1.3993)was lower than that of the sensitive isolates(1.7499),implying a reduced affinity between SDHB and boscalid as a potential mechanism underlying the boscalid resistance in S.sclerotiorum.These findings contribute to an enhanced comprehension of boscalid’s mode of action and furnish valuable insights into the management of boscalid resistance.展开更多
[Objective] This study aimed to avoid and delay the generation of resis- tance in Botrytis cinerea to boscalid. [Method] The sensitivity of Botrytis cinerea to boscalid was tested by the mycelial growth rate method. T...[Objective] This study aimed to avoid and delay the generation of resis- tance in Botrytis cinerea to boscalid. [Method] The sensitivity of Botrytis cinerea to boscalid was tested by the mycelial growth rate method. The distribution of sensitivity variation of B. cinerea to boscalid in different regions was cleared, and the sen- sitivity baseline of B. cinerea from Liaoning Province to boscalid was established. [Result] The ECso values of B. cinerea strains from Liaoning Province ranged from 0.080 0 to 7.787 2μg/ml, and the highest ECho value was 97.34 times higher than the minimum. The average EC50 value （1.973μg/ml） of the 158 strains was treated as the baseline sensitivity of B. cinerea from Liaoning Province to boscalid. [Conclu- sion] It is essential to conduct a risk assessment of drug resistance in B. cinerea to boscalid.展开更多
Gray mold caused by Botrytis cinerea is a major disease of greenhouse cucumbers and its control is largely dependent on the succinate dehydrogenase inhibitor boscalid.In this study,gray mold-infected cucumbers were co...Gray mold caused by Botrytis cinerea is a major disease of greenhouse cucumbers and its control is largely dependent on the succinate dehydrogenase inhibitor boscalid.In this study,gray mold-infected cucumbers were collected from greenhouses located in 11 towns in which boscalid had been used,and 163 B.cinerea strains were isolated by single-spore method.The EC50 value effective concentration that could inhibit conidia germination by 50%compared with the control for sensitive isolates ranged from 0.045μg/mL to 50.148μg/mL in the assays.Additionally,101 isolates were resistant to boscalid,and the resistance frequency ranged from 33.33%to 86.67%in these towns.Most of the resistant isolates showed a low or moderately resistant phenotype,with the resistance frequency of moderately resistant isolates being as high as 80%.The SdhB gene harbored a single mutation corresponding to His272.The fitness evaluation showed that the hyphal growth,sporulation,germinability and pathogenicity were different among the resistant and sensitive isolates.The results suggested that dual resistance to boscalid in B.cinerea populations could result in failure to control gray mold.展开更多
A total of 96 monoconidial Botrytis cinerea strains were isolated from strawberry field.Physiological characteristics and resistance analysis to boscalid were investigated.Most isolates showed resistant phenotype and ...A total of 96 monoconidial Botrytis cinerea strains were isolated from strawberry field.Physiological characteristics and resistance analysis to boscalid were investigated.Most isolates showed resistant phenotype and the resistance frequency of highly resistant isolates was as high as 45.10%.The effective concentration that inhibited conidia germination by 50% relative to the control values for sensitive isolates ranged from 0.068 to 60.56μg·mL^-1 in conidia germination assays.Compared to the sensitive strains,the boscalid-resistant strains had a significant increase in phenylalanine ammonia lyase(PAL)and peroxidase(POD)activity and more sensitivity to boscalid pressure.Fitness analysis showed statistically significant difference between sensitive and resistance isolates.Sequencing of SdhB gene indicated that a single mutation corresponded to His272.The results suggested that resistance to boscalid in B.cinerea populations could result in failure to control gray mold.These results would enrich the understanding of the resistance mechanism of B.cinerea to boscalid.展开更多
Abstract [Objective] This study was conducted to evaluate the ecotoxicity of boscalid to adult zebrafish （Danio rerio）. [Method] The activities of antioxidant enzymes superoxide dismutase （SOD）, catalase （CAT）, ...Abstract [Objective] This study was conducted to evaluate the ecotoxicity of boscalid to adult zebrafish （Danio rerio）. [Method] The activities of antioxidant enzymes superoxide dismutase （SOD）, catalase （CAT）, peroxidase （POD）, glutathione peroxidase （GPx）, as well as a non-enzymatic antioxidant malondialdehyde （MDA）, in the liver were measured 3, 7, 14 and 21 d post exposure （dpe） to 0.02 （1/100 of acute toxicity）, 0.036 （monitored concentration）, 0.08 （1/20 of acute toxicity）, 0.16 （1/10 of acute toxicity） and 0.32 mg/L （1/5 of acute toxicity） boscalid using a semi-static method. [Result] SOD, CAT, POD, GPx and MDA activity in the liver of zebrafish varied with boscalid concentration and exposure time. Boscalid significantly enhanced MDA content at 21 dpe. A significant upregulation of the activity of SOD, CAT, POD and GPx at 7 dpe was observed, suggesting that boscalid resulted in oxidative stress and lipid peroxidation. [Conclusion] These results show that these biomarkers are all appropriate for monitoring oxidative stress and the lipid peroxidation status of fish after exposure to boscalid. Key words Boscalid; Zebrafish; Antioxidant enzyme展开更多
监测月季灰霉病抗药性发生现状,探索防控药剂的应用技术。病原鉴定采用分子鉴定和形态学鉴定法,抗药性监测采用菌落生长区分剂量法,田间试验采用喷雾法。3省份采集分离的月季灰霉病菌株均为灰葡萄孢菌。抗性监测结果表明,采集的月季灰...监测月季灰霉病抗药性发生现状,探索防控药剂的应用技术。病原鉴定采用分子鉴定和形态学鉴定法,抗药性监测采用菌落生长区分剂量法,田间试验采用喷雾法。3省份采集分离的月季灰霉病菌株均为灰葡萄孢菌。抗性监测结果表明,采集的月季灰霉病菌对多菌灵、嘧菌酯和戊唑醇的抗性频率分别为66.67%、50%和77.78%,应降低使用频次。田间药效试验结果表明,推荐剂量下啶酰菌胺和嘧霉胺对月季灰霉病的防效分别为70%~88%和70%~84%,两者在江苏的防效均>80%。植物安全性试验结果表明,啶酰菌胺在有效剂量225、450、900 g a.i./hm2嘧霉胺在有效剂量800、1600、3200 g a.i./hm2范围内对月季安全。基于本研究成果,建议生产上可使用啶酰菌胺和嘧霉胺防控月季灰霉病,注意轮换用药。展开更多
基金supported by the Jiangsu Provincial Key Research and Development, China (BE2021361)the Jiangsu Agriculture Science and Technology Innovation Fund ((CX(21)2037 and CX(22)3072))the National Natural Science Foundation of China (31672065)。
文摘Laboratory mutants of Sclerotinia sclerotiorum(Lib)de Bary,resistant to boscalid,have been extensively characterized.However,the resistance situation in the lettuce field remains largely elusive.In this study,among the 172 S.sclerotiorum isolates collected from asparagus lettuce field in Jiangsu Province,China,132 isolates(76.74%)exhibited low-level resistance to boscalid(Bos^(LR)),with a discriminatory dose of 5μg mL-1.In comparison to the boscalid-sensitive(BosS)isolates,most Bos^(LR)isolates demonstrated a slightly superior biological fitness,as evidenced by data on mycelial growth,sclerotium production and pathogenicity.Moreover,most Bos^(LR)isolates showed comparable levels of oxalic acid(OA)accumulation,increased exopolysaccharide(EPS)content and reduced membrane permeability when compared to the BosS isolates.Nevertheless,their responses to distinct stress factors diverged significantly.Furthermore,the effectiveness of boscalid in controlling Bos^(LR)isolates on radish was diminished compared to its efficacy on BosS isolates.Genetic mutations were identified in the SDH genes of Bos^(LR)isolates,revealing the existence of three resistant genotypes:I(^(A11V)at SDHB,SDHB^(A11V)),II(^(Q38R)at SDHC,SDHC^(Q38R))and III(SDHB^(A11V)+SDHC^(Q38R)).Importantly,no cross-resistance was observed between boscalid and other fungicides such as thifluzamide,pydiflumetofen,fluazinam,or tebuconazole.Our molecular docking analysis indicated that the docking total score(DTS)of the type I resistant isolates(1.3993)was lower than that of the sensitive isolates(1.7499),implying a reduced affinity between SDHB and boscalid as a potential mechanism underlying the boscalid resistance in S.sclerotiorum.These findings contribute to an enhanced comprehension of boscalid’s mode of action and furnish valuable insights into the management of boscalid resistance.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest of China(201303025)~~
文摘[Objective] This study aimed to avoid and delay the generation of resis- tance in Botrytis cinerea to boscalid. [Method] The sensitivity of Botrytis cinerea to boscalid was tested by the mycelial growth rate method. The distribution of sensitivity variation of B. cinerea to boscalid in different regions was cleared, and the sen- sitivity baseline of B. cinerea from Liaoning Province to boscalid was established. [Result] The ECso values of B. cinerea strains from Liaoning Province ranged from 0.080 0 to 7.787 2μg/ml, and the highest ECho value was 97.34 times higher than the minimum. The average EC50 value （1.973μg/ml） of the 158 strains was treated as the baseline sensitivity of B. cinerea from Liaoning Province to boscalid. [Conclu- sion] It is essential to conduct a risk assessment of drug resistance in B. cinerea to boscalid.
基金Supported by the National Natural Science Foundation of China(31501665)the Application Program of Yuncheng University(CY2018016)the Doctoral Fund of Yuncheng University(YQ-2018012) and Subject Program of Yuncheng University(XK-2018006)~~
文摘Gray mold caused by Botrytis cinerea is a major disease of greenhouse cucumbers and its control is largely dependent on the succinate dehydrogenase inhibitor boscalid.In this study,gray mold-infected cucumbers were collected from greenhouses located in 11 towns in which boscalid had been used,and 163 B.cinerea strains were isolated by single-spore method.The EC50 value effective concentration that could inhibit conidia germination by 50%compared with the control for sensitive isolates ranged from 0.045μg/mL to 50.148μg/mL in the assays.Additionally,101 isolates were resistant to boscalid,and the resistance frequency ranged from 33.33%to 86.67%in these towns.Most of the resistant isolates showed a low or moderately resistant phenotype,with the resistance frequency of moderately resistant isolates being as high as 80%.The SdhB gene harbored a single mutation corresponding to His272.The fitness evaluation showed that the hyphal growth,sporulation,germinability and pathogenicity were different among the resistant and sensitive isolates.The results suggested that dual resistance to boscalid in B.cinerea populations could result in failure to control gray mold.
基金Supported by the National Natural Science Foundation of China(31501665)the Program for the Scientific and Technologal Innovation Programs Higher Education Institutions in Shanxi(2019L0849,2019L0851)+1 种基金the Opening Foundation of Key Laboratory of Environment Change and Resources Use in Beibu Gulf Ministry of Education(Nanning Normal University)Guangxi Key Laboratory of Earth Surface Processes and Intelligent Simulation(Nanning Normal University)(NNNU-KLOP-K1904)
文摘A total of 96 monoconidial Botrytis cinerea strains were isolated from strawberry field.Physiological characteristics and resistance analysis to boscalid were investigated.Most isolates showed resistant phenotype and the resistance frequency of highly resistant isolates was as high as 45.10%.The effective concentration that inhibited conidia germination by 50% relative to the control values for sensitive isolates ranged from 0.068 to 60.56μg·mL^-1 in conidia germination assays.Compared to the sensitive strains,the boscalid-resistant strains had a significant increase in phenylalanine ammonia lyase(PAL)and peroxidase(POD)activity and more sensitivity to boscalid pressure.Fitness analysis showed statistically significant difference between sensitive and resistance isolates.Sequencing of SdhB gene indicated that a single mutation corresponded to His272.The results suggested that resistance to boscalid in B.cinerea populations could result in failure to control gray mold.These results would enrich the understanding of the resistance mechanism of B.cinerea to boscalid.
文摘Abstract [Objective] This study was conducted to evaluate the ecotoxicity of boscalid to adult zebrafish （Danio rerio）. [Method] The activities of antioxidant enzymes superoxide dismutase （SOD）, catalase （CAT）, peroxidase （POD）, glutathione peroxidase （GPx）, as well as a non-enzymatic antioxidant malondialdehyde （MDA）, in the liver were measured 3, 7, 14 and 21 d post exposure （dpe） to 0.02 （1/100 of acute toxicity）, 0.036 （monitored concentration）, 0.08 （1/20 of acute toxicity）, 0.16 （1/10 of acute toxicity） and 0.32 mg/L （1/5 of acute toxicity） boscalid using a semi-static method. [Result] SOD, CAT, POD, GPx and MDA activity in the liver of zebrafish varied with boscalid concentration and exposure time. Boscalid significantly enhanced MDA content at 21 dpe. A significant upregulation of the activity of SOD, CAT, POD and GPx at 7 dpe was observed, suggesting that boscalid resulted in oxidative stress and lipid peroxidation. [Conclusion] These results show that these biomarkers are all appropriate for monitoring oxidative stress and the lipid peroxidation status of fish after exposure to boscalid. Key words Boscalid; Zebrafish; Antioxidant enzyme
文摘监测月季灰霉病抗药性发生现状,探索防控药剂的应用技术。病原鉴定采用分子鉴定和形态学鉴定法,抗药性监测采用菌落生长区分剂量法,田间试验采用喷雾法。3省份采集分离的月季灰霉病菌株均为灰葡萄孢菌。抗性监测结果表明,采集的月季灰霉病菌对多菌灵、嘧菌酯和戊唑醇的抗性频率分别为66.67%、50%和77.78%,应降低使用频次。田间药效试验结果表明,推荐剂量下啶酰菌胺和嘧霉胺对月季灰霉病的防效分别为70%~88%和70%~84%,两者在江苏的防效均>80%。植物安全性试验结果表明,啶酰菌胺在有效剂量225、450、900 g a.i./hm2嘧霉胺在有效剂量800、1600、3200 g a.i./hm2范围内对月季安全。基于本研究成果,建议生产上可使用啶酰菌胺和嘧霉胺防控月季灰霉病,注意轮换用药。
