Plant roots interact with diverse fungi that are essential for maintaining the productivity and sustainability of pasture ecosystems,but how these root-associated fungi(RAF)differ between forage species and how they r...Plant roots interact with diverse fungi that are essential for maintaining the productivity and sustainability of pasture ecosystems,but how these root-associated fungi(RAF)differ between forage species and how they respond to nutrient enrichment and fungicide application are not well understood.Here,we constructed an 11-year experiment involving fungicide application(with or without)nested within four levels of experimental nitrogen(N)addition treatments in an alpine pasture,and the RAF communities,root traits,tissue nutrients,and shoot biomass of two dominant forage species(Carex capillifolia and Elymus nutans)were analyzed.The RAF community composition showed striking differences between the plant species and was strongly affected by both N addition level and fungicide applications.Fungicide,but not N application,dramatically reduced the RAF richness of all functional guilds in both plant species,and fungicide also simplified the co-occurrence network of the RAF for C.capillifolia.The RAF community correlated strongly with root traits,whereas their relationships became weakened or even vanished at the level of the individual plant species.The importance of RAF to plant nutrients and productivity varied between plant species,with significant contributions in C.capillifolia but not in E.nutans.This is the first report elucidating the long-term effect of fungicides on RAF in alpine pastures,and our findings emphasize the host-specific responses of RAF community structure and function to anthropogenic disturbances.展开更多
[Objectives]This study was conducted to improve the purification agent combination conditions for QuEChERS and establish a method for detecting the residues of 18 fungicides in animal-derived foods(fish,pork,milk,eggs...[Objectives]This study was conducted to improve the purification agent combination conditions for QuEChERS and establish a method for detecting the residues of 18 fungicides in animal-derived foods(fish,pork,milk,eggs,and pork liver)using high-performance liquid chromatography-triple quadrupole tandem mass spectrometry.[Methods]The samples were extracted with acetonitrile,purified with 885 mg of magnesium sulfate,150 mg of PSA(ethylenediamine-N-propylsilane silica gel),and 15 mg of GCB(graphitized carbon black),and analyzed using ACQUITY UPLC BEH C 18 as the chromatographic column with a mobile phase of acetonitrile-0.1%formic acid aqueous solution.[Results]The 18 fungicides showed good linearity in the range of 5.00–200.00μg/L,with correlation coefficients(R^(2))greater than 0.991.The limit of quantification(LOQ)was 0.01 mg/kg.The average recoveries ranged from 63.7%to 117.5%,and the relative standard deviations(RSDs)were between 0.22%and 6.33%.[Conclusions]This method is simple,rapid,and highly accurate,and provides technical reference for the detection and risk assessment of fungicides in animal-derived foods.展开更多
In recent years,the prevalence of rice sheath blight caused by Rhizoctonia solani has significantly increased in Heilongjiang Province.Chemical control has become the primary control method.To cope with this,a novel m...In recent years,the prevalence of rice sheath blight caused by Rhizoctonia solani has significantly increased in Heilongjiang Province.Chemical control has become the primary control method.To cope with this,a novel mycelium growth rate method was employed to assess the toxicity of 13 fungicides,including a combination of 45%prochloraz and 125 g·mL^(-1)epoxiconazole,against R.solani.Additionally,the resistance of 99 R.solani strains to thifluzamide across various regions was also evaluated.The findings indicated that 75%trifloxystrobin-tebuconazole exhibited the most effective inhibitory effect,with an effective inhibitory medium concentration(EC50)value of 0.0101μg·mL^(-1).The EC50 values for 20%prothioconazole,125 g·mL^(-1)epoxiconazole,24%thifluzamide,and 50%hexaconazole were all less than 10μg·mL^(-1),indicating a better inhibitory effect on R.solani.The strongest synergistic effect was noted in the mixture of prochloraz and epoxiconazole at a 1:2 ratio,resulting in an EC50 value of 2.9917μg·mL^(-1),and a co-toxicity coefficient of 213.38.Among the 34 strains from Harbin City,the average EC50 value was 196.9341μg·mL^(-1)indicating the highest susceptiblility to thifluzamide.Conversely,15 strains from Shuangyashan City exhibited an average EC50 value of 364.7323μg·mL^(-1),reflecting the lowest sensitivity to thifluzamide.The sensitivity baseline EC50 value for R.solani was 253.8854μg·mL^(-1),with an overall resistance level between 0.1567 and 3.3292,indicating that the resistance level of R.solani in Heilongjiang Province remained low.Therefore,R.solani was still sensitive to thifluzamide in most areas of Heilongjiang Province,but there was a certain risk of resistance in Qitaihe City,which needed to be continuously monitored.At the same time,this study might provide a theoretical foundation for enhancing the prevention and management of the rice sheath blight.展开更多
In yeast,the stress-responsive protein Whi2 interacts with phosphatase Psr1 to form a complex that regulates cell growth,reproduction,infection,and the stress response.However,the roles of Whi2 and Psr1 in Fusarium gr...In yeast,the stress-responsive protein Whi2 interacts with phosphatase Psr1 to form a complex that regulates cell growth,reproduction,infection,and the stress response.However,the roles of Whi2 and Psr1 in Fusarium graminearum remain unclear.In this study,we identified homologous genes of WHI2 and PSR1 in F.graminearum and evaluated their functions by constructing deletion mutants.By comparing the responses of the mutants to different stressors,we found that FgWHI2 and FgPSR1 were involved in responding to osmotic,cell wall and cell membrane stresses,while also affecting the sexual and asexual reproduction in F.graminearum.Our studies demonstrated that FgWHI2 and FgPSR1 regulate the biosynthesis of ergosterol and the transcriptional level of FgCYP51C,which is a CYP51 paralogues unique to Fusarium species.This study also found that the deoxynivalenol(DON)production of FgWHI2 and FgPSR1 deletion mutants was reduced by≥90%and DON production was positively correlated with the transcriptional levels of FgWHI2 and FgPSR1.In addition,we observed that FgWHI2 and FgPSR1 were involved in regulating the sensitivity of F.graminearum to chlorothalonil,fluazinam,azoxystrobin,phenamacril,and oligomycin.This study revealed cross-resistance between chlorothalonil and fluazinam.Meanwhile,chlorothalonil and fluazinam inhibited DON biosynthesis by altering the normal expression of FgWhi2 and FgPsr1.Interestingly,the subcellular localization of FgWhi2 and FgPsr1 was significantly altered after treatment with chlorothalonil and fluazinam,with increased co-localization.Collectively,these findings indicate that FgWHI2 and FgPSR1 play crucial roles in stress response mechanisms,reproductive processes,secondary metabolite synthesis,and fungicide sensitivity in F.graminearum.展开更多
[Objective] This study was conducted to determine the toxicity of 26 fungicides against Oidium heveae and the synergistic effects of their binary mixtures.[Method] The sensitivity of O.heveae to 26 fungicides was dete...[Objective] This study was conducted to determine the toxicity of 26 fungicides against Oidium heveae and the synergistic effects of their binary mixtures.[Method] The sensitivity of O.heveae to 26 fungicides was determined in vitro and in vivo by calculating EC50 values.Horsfall＇s toxicity rate was preliminarily employed to predict the type of joint action of 180 two-way mixtures,based on which the interaction level of the potentially synergistic mixtures was validated by Sun and Johnson＇s co-toxicity coefficient.[Result] Triflumizole,pyraoxystrobin,flufenoxystrobin,epoxiconazole,pyrametostrobin,flusilazole,pyraclostrobin and tetraconazole were the most potent inhibitors of both spore germination and mycelial growth.An ‘in vitro-in vivo＇ integrated strategy is proposed for screening the inhibitors of O.heveae,according to the fact that data obtained in germination experiment are able to reflect to some extent the effectiveness of fungicide confirmed by pot experiment.Results achieved by Horsfall＇s were in line with that validated by Sun and Johnson＇s,the Horsfall＇s seems to be a convenient means to assess rapidly the potential interaction type and level of fungicides in a binary mixture.Nineteen mixtures interact synergistically：epoxiconazole ＋ pyraclostrobin at the mixing ratio of 6：4,8：2;tetraconazole ＋ flufenoxystrobin at 1：9,2：8,3：7 and 4：6;triadimefon ＋ flufenoxystrobin at 9：1;triflumizole ＋ flufenoxystrobin at 8：2;flusilazole ＋pyrametostrobin at 7：3,8：2 and 9：1;tetraconazole ＋ pyrametostrobin at 6：4;triadimefon ＋ pyrametostrobin at 5：5,8：2;triflumizole ＋ pyrametostrobin at 7：3,8：2;tetraconazole ＋ pyraoxystrobin at 9：1;triflumizole ＋ pyraoxystrobin at 8：2,9：1.[Conclusion] The single fungicides and their binary mixtures are expected to serve as the alternatives to triadimefon and the alternate use of them could delay the buildup of resistant O.heveae isolate.展开更多
[Objective] This study aimed to screen effective fungicide for prevention and control of apple powdery mildew. [Method] Field efficacy of six kinds of fungi- cides with 18 concentrations against apple powdery mildew w...[Objective] This study aimed to screen effective fungicide for prevention and control of apple powdery mildew. [Method] Field efficacy of six kinds of fungi- cides with 18 concentrations against apple powdery mildew was investigated. [Re- sult] 4 000-fold triflumizole WP exhibited the highest control efficacy of 82.96%, fol- lowed by 3 000-fold triflumizole WP with control efficacy of 77.75%, while 800-fold and 1 000-fold 70% thiophanate methyl WP exhibited relatively low control efficacy, which was both lower than 60%. [Conclusion] In actual production, 4 000-fold triflu- mizole WP and 3 000-fold triflumizole WP should be used alternately to control and prevent apple powdery mildew.展开更多
For exploring the influences of application and residue of chemical fungi- cides on chlamydospore preparations of Trichoderma spp., the effects of seven chemical fungicides on chlamydospore germination and mycelia gro...For exploring the influences of application and residue of chemical fungi- cides on chlamydospore preparations of Trichoderma spp., the effects of seven chemical fungicides on chlamydospore germination and mycelia growth of two bio- control fungi T. harzianum 610 and T. Iongibrachiatum 758 were studied. Carben- dazim, tebuconazole and difenoconazole showed strong toxicities, thiram and car- bexin showed moderate toxicities, and metalaxyl showed Mycelia growth of the two strains was more sensitive to most tested fungicides than those of chlamydospore germination. Chlamydospore germination of 610 was more sensitive to tested fungicides than those of 758, and mycelia growth of 758 was more sensitive to most tested fungi- cides than those of 610. Among the seven fungicides, 98% carbendazim had the strongest effects （ECru values were 1.64 and 0.05μpg/ml）, and 70% pentachloroni- trobenzene had the weakest effects （EC50 values were 1.64 and 0,05 μg/ml） for chlamydospore germination and mycelia growth of 610. As for 758, 98% carbendaz- im had the strongest inhibitory effects and 95% metalaxyl had the weakest inhibitory for chlamydospore germination of 756 （EC50 values were 0.62 and 1 108.61 μg/ml respectively）, whereas 96.2% tebuconazole showed the strongest inhibitory effects for mycelia growth of 758 （EC= value was 0.32μg/ml）, and 95% metalaxyl was the weakest （EC= value was 1 206.29 μg/ml）. According to the applied concentration of different fungicides in practice, we concluded that chlamydospore preparations of 610 and 758 could not be combined with carbendazim, tebuconazole, thiram and carboxin for controlling plant diseases, and the pesticide residues to the biocontrol effects should be kept in mind. Chlamydospore preparations of 610 and 758 can be and difenoconazole for controlling plant dis- eases, 758 chlamydospore preparations and germinated chlamydospore of 610 can be combined with metalaxyl for controlling plant diseases, and pesticide residue risk was not serious.展开更多
[Objective] This study was conducted to screen suitable fungicides to con-trol ginseng leaf blight caused by Alternaria panax_Whetz. [Method] The antifungal activity of seven fungicides against A. panax_ was determine...[Objective] This study was conducted to screen suitable fungicides to con-trol ginseng leaf blight caused by Alternaria panax_Whetz. [Method] The antifungal activity of seven fungicides against A. panax_ was determined based on mycelial growth rate in vitro. [Result] The results of in vitro antibiotic activity assay showed that there were significant differences in inhibition rate among different concentration treatments of each of the seven fungicides. Toxicity test results showed that among the seven fungicides, difenoconazole had the smal est EC50 （0.61 mg/L）, fol owed by streptomycin and captan, with EC50 value lower than 100 mg/L. [Conclusion] A fungicide which had strong antifungal activity on A. panax was screened out, and the results wil provide a theoretical basis for further field trial.展开更多
This report reviews the characteristics of JS399-19, a novel cyanoacrylate fungicide. JS399-19 strongly inhibits the mycelial growth of the fungal plant pathogens of the genus Fusarium and exhibits great potential in ...This report reviews the characteristics of JS399-19, a novel cyanoacrylate fungicide. JS399-19 strongly inhibits the mycelial growth of the fungal plant pathogens of the genus Fusarium and exhibits great potential in controlling Fusarium head blight （FHB） on wheat and other cereals. The mode of action of JS399-19 is evidently different from that of benzimidazole （for example, carbendazim） and other sort of fungicides, making it a possible replacement for carbendazim in China to manage carbendazim-resistant subpopulations of Fusarium graminearum and F. asiaticum. JS399-t9 has excellent protective and curative activity against these pathogens. Incorrect use of this fungicide, however, is likely to select for resistance. Among JS399-19-resistant mutants of F. asiaticum induced in the laboratory, the resistant level of mutants was high and the phenotype of resistance against JS399-19 was conferred by a major gene by genetic analysis. The fitness of laboratory-induced JS399-19-resistant mutants of F. asiaticum was nearly equal to that of their parents. JS399-19 lacks cross resistance with other sort fungicides. To control FHB with JS399-19 and to delay the development of the fungicide-resistance, farmers should use tank mixtures containing JS399-19 and carbendazim, metconazole, tebuconazole, or prothioconazole.展开更多
[Objective] The aim was to study the effect of three new fungicides against rice sheath blight in field experiment. [Methods] The experiment set up 7 treatments with three times of repetition and designed by random gr...[Objective] The aim was to study the effect of three new fungicides against rice sheath blight in field experiment. [Methods] The experiment set up 7 treatments with three times of repetition and designed by random grouping. By using 5 sampling points in each plot, and investigating continuous 4 holes of each point, total plants, diseased plants and disease degrees were recorded. Then disease index and control efficiency were calculated, and variance analysis was carried out. [Results] 300 or 450 ml/hm^2 azoxystrobin ＋ difenoconazole 325 g/L SC had better control efficiency to rice sheath blight and had no phytotoxicity effect, we should use it at the initial disease stage and continuously spray 2-3 times. [Conclusion] The experiment provided a theoretical basis for controlling rice sheath blight using fungicides.展开更多
[Objective] The research aimed to isolate and identify the pathogen of anthracnose of Ligusticum chuanxiong Hort,and make the antifungal test on four kinds of fungicides for selecting the optimum fungicides.[Method] T...[Objective] The research aimed to isolate and identify the pathogen of anthracnose of Ligusticum chuanxiong Hort,and make the antifungal test on four kinds of fungicides for selecting the optimum fungicides.[Method] The pathogenic fungi was separated according to Koch＇s rule and the shape characteristics were identified. The antifungal test of fungicides was made by using plate mycelium growth inhibition method.[Result] The pathogenic fungi was separated from leaves of Ligusticum chuanxiong Hort. and morphological characters were consistent with that of Colletotrichum gloeosporioides. In addition to chloroisobromine cyanuric acid,the other three fungicides could inhibit the mycelium growth. The growth inhibition rates of 1 000 times Metalaxyl＋mancozeb,zineb,Thiophanate-methyl for the mycelium were 26.8%,22.1%,59.8% respectively after 7 days.[Conclusion] The anthracnose was caused by Colletotrichum gloeosporioides. Ligusticum chuanxiong Hort. was a new record host plant of Colletotrichum gloeosporioides and the best inhibiting fungicide was Thiophanate methyl.展开更多
[Objective] This study aims to screen for the high effective fungicides which could significantly decrease the disease incidence and disease index of rice false smut. [Method] The inhibitory activities of the fungicid...[Objective] This study aims to screen for the high effective fungicides which could significantly decrease the disease incidence and disease index of rice false smut. [Method] The inhibitory activities of the fungicide against mycelial growth of Ustilaginoidea virens were measured to in vitro evaluate the ECho values. And 17 fungicides were sprayed to evaluate the efficacy and effect of the fungicides tested in the field trials on the rice characters, [Result] The results showed that epoxicona- zole, difenoconazole, propiconazole and procloraz exhibited high inhibitory activity against mycelial growth of Ustilaginoidea virens with the ECso values 0.04, 0.07, 0.12 and 0.11 pg/ml, respectively. The results of field trials showed that the efficacy of Wen- quning, and fungicides such as difenoconazole, prochloraz, propiconazole, epoxi- conazole and their mixtures in controlling rice false smut were all 70% or more. [Conclusion] The 17 tested fungicides behaved efficacy in controlling rice false smut and did not cause drug injury on leaves and grains of rice plants, sprayed when flag leaves of rice fully expanded.展开更多
In this research,the inhibitory effect of 16 fungicides on Colletotrichum horri causing persimmon anthracnose was investigated using mycelial growth method and spore germination method. The results showed that among t...In this research,the inhibitory effect of 16 fungicides on Colletotrichum horri causing persimmon anthracnose was investigated using mycelial growth method and spore germination method. The results showed that among the 16 tested fungicides,10% of Difenoconazole WG,33. 5% of Copper quinolate SC,25%of Bromothalonil EC,70% of Mancozeb WP,430 g/L of Tebuconazole SC,50% of Prochloraz-manganese chloride and 400 g/L of Flusilazole EC achieved the best inhibitory effect on mycelial growth of C. horri,with the inhibition rate of 100%; 70% of Polyram WG,33. 5% of Copper quinolate SC,25% of Bromothalonil EC,70% of Mancozeb WP,50% of Chlorobromoisocyanuric acid AF,50% of Triram WP and 400 g/L of Flusilazole achieved the best inhibitory effect on spore germination of C. horri,with the germination rate of 0. In conclusion,33. 5% of Copper quinolate SC,25% of Bromothalonil EC,70% of Mancozeb WP and 400 g/L of Flusilazole EC achieved the best inhibitory effect both in mycelial growth and spore germination,which could be used as the preference fungicides for the control of persimmon anthracnose,and 70% of Polyram WG and 50% of Triram WP achieved the secondly best inhibitory effect,which could be used as alternative fungicides. The results of this research could provide scientific evidence for the effective control of persimmon anthracnose,and more optional pesticides for utilization in the production practice of persimmon industry.展开更多
[Objective] This study aimed to investigate the resistance to different fungicides in Phytophthora parasitica var. nicotianae. [Method] Under indoor incubation conditions, the resistance to dimethomorph, metalaxyl-man...[Objective] This study aimed to investigate the resistance to different fungicides in Phytophthora parasitica var. nicotianae. [Method] Under indoor incubation conditions, the resistance to dimethomorph, metalaxyl-mancozeb, propamocarb and ovraclostrobin.dimethomorph in P. parasitica strain isolated from Zhenyuan County in Qiandongnan State was analyzed with colony growth measurement method. [Result] P. parasitica exhibited different levels of sensitivity to four fungicides. To be specific, P. parasitica exhibited the highest resistance to dimethomorph, and ECho reached 1.19 μg/ml. [Conclusion] In Zhenyuan tobacco-growing area, long-term single use of dimethomorph possesses certain resistance risk in prevention and control of black shank disease.展开更多
Fungicides have been used extensively for controlling fungal pathogens of plants. However, little is known regarding the effects that fungicides upon the indigenous bacterial communities within the plant phyllosphere....Fungicides have been used extensively for controlling fungal pathogens of plants. However, little is known regarding the effects that fungicides upon the indigenous bacterial communities within the plant phyllosphere. The aims of this study were to assess the impact of fungicide enostroburin upon bacterial communities in wheat phyllosphere. Culture-independent methodologies of 16S rDNA clone library and 16S rDNA directed polymerase chain reaction with denaturing gradient gel electrophoresis （PCR-DGGE） were used for monitoring the change of bacterial community. The 16S rDNA clone library and PCR-DGGE analysis both confirmed the microbial community of wheat plant phyllosphere were predominantly of the γ-Proteobacteria phyla. Results from PCR-DGGE analysis indicated a significant change in bacterial community structure within the phyllosphere following fungicide enostroburin application. Bands sequenced within control cultures were predominantly of Pseudomonas genus, but those bands sequenced in the treated samples were predominantly strains of Pantoea genus and Pseudomonas genus. Of interest was the appearance of two DGGE bands following fungicide treatment, one of which had sequence similarities （98%） to Pantoea sp. which might be a competitor of plant pathogens. This study revealed the wheat phyllosphere bacterial community composition and a shift in the bacterial community following fungicide enostroburin application.展开更多
The proportion of organic matter and mineral composition are important factors determining the formation and type of non-extractable residues(NERs) of pesticides in soil. In this study, we investigated the enantiosele...The proportion of organic matter and mineral composition are important factors determining the formation and type of non-extractable residues(NERs) of pesticides in soil. In this study, we investigated the enantioselectivity in degradation and NER formation of the chiral fungicide metalaxyl in soil particle size fractions(silt and clay). Microbial and extracellular enzyme activities during these processes were monitored in incubation of silt and clay samples isolated from sterilized and non-sterilized soil samples collected from a long-term agricultural field experimental site in Ultuna, Sweden. The temporal influence on the fate of the fungicide was noted by short-term(10-d) and long-term(92-d) incubations. Besides the acquisition of quantitative data with gas chromatography-mass spectrometry(GC/MS), stereoselective analyses were performed with chiral GC/MS. Quantitative results pointed to a higher metabolism rate of the pesticide through microbial activity than through extracellular enzyme activity. This was also confirmed by the enantioselective depletion of R-metalaxyl and the subsequent formation of R-metalaxyl acid in microbially active samples from non-sterilized soil. The silt fraction containing a high amount of organic matter exhibited a significant hydrolyzable proportion of metalaxyl NERs that was releasable under alkaline conditions. On the contrary, the clay fraction showed an enhanced affinity for covalently bound residues. Based on our results, we recommend differentiating between reversibly and irreversibly bound proportions of pesticides in persistence and environmental risk assessment because the reversible fraction contained potentially bioavailable amounts of residues that may be released under natural conditions.展开更多
The effects of biofungicide formula containing the biocontrol agent Trichoderma harzianum (Jn14) as wettable powder in combination with the fungicides pyrimethanil and a mixture of cyprodinil and flydioxonil on Botryt...The effects of biofungicide formula containing the biocontrol agent Trichoderma harzianum (Jn14) as wettable powder in combination with the fungicides pyrimethanil and a mixture of cyprodinil and flydioxonil on Botrytis cinerea of strawberry in vitro, in vivo and in greenhouse were studied. The pathogen B. cinerea was more affected in vitro by low concentrations of the fungicides tested above 0.4 μg·ml-1 than the bioagent T. harzianum (Jn14). The later was almost insensitive to pyrimethanil. In the same direction, gray mould disease severity on strawberry detached leaves and whole plants was reduced up to 89% by the tested fungicides, compared to the control, while the application of T. harzianum (Jn14) alone reduced disease severity up to 45% on strawberry detached leaves, compared to the control. In the integrated control approach, the combination of T. harzianum (Jn14) with higher concentrations of the tested fungicides (ED50) completely inhibited strawberry gray mould disease severity in pots and the greenhouse.展开更多
Two seed lots of lettuce (Lactuca sativa L.) cv. Krlowa Majowych were primed in polyethylene glycol (PEG) 8000 at -1.25MPa for 7 days in dark at 20C. Two fungicide treatments combined with PEG were used to control fun...Two seed lots of lettuce (Lactuca sativa L.) cv. Krlowa Majowych were primed in polyethylene glycol (PEG) 8000 at -1.25MPa for 7 days in dark at 20C. Two fungicide treatments combined with PEG were used to control fungi: 1) Funaben T(0.1%) and Apron 35 SD (0.02%) were added to -1.25 MPa PEG solution (PEG+F); 2) After seed priming and drying,Funaben T was mixed at 5 g kg-1 and Apron 35 SD at 1 g kg-1 of seeds (PEG then F dust). PEG, PEG+F and PEG then F dusttreatments reduced significantly thermodormancy and increased the seed germination at 35C in both lots. PEG then Fdust treatment had the best effect on reducing seed thermodormancy at 35C, and increased seed germination to 64.5% inlot 1 and 72.0% in lot 2 compared to 0 in untreated. PEG and PEG then F dust treatments have accelerated germinationspeed at 20 and 15C in both lots. There was a significant reduction in seed infestation in which the seeds were treatedwith PEG+F and PEG then F dust compared to untreated seeds and PEG primed seeds. PEG priming enhanced seedinfestation considerably by Alternaria alternata, Penicillium spp., Rhizopus spp. and Ulocladium spp. Mycologicalanalysis showed higher frequency of Alternaria alternata and Ulocladium spp. in untreated seeds at 20C. Priming incombination with fungicides significantly alleviated the infestation of fungi, especially Alternaria alternata infestation.展开更多
Tobacco black shank caused by Phytophthora parasitica var.nicotianae(Breda de Hean)is one of the most serious diseases in tobacco growing,and few effective fungicides are available currently.The purpose of this study ...Tobacco black shank caused by Phytophthora parasitica var.nicotianae(Breda de Hean)is one of the most serious diseases in tobacco growing,and few effective fungicides are available currently.The purpose of this study was to assess the feasibility of using fluazinam to treat tobacco black shank disease.In vitro toxicities of fluazinam to 62 isolates of P.nicotianae were determined by mycelial growth rate method.The EC50 values ranged from 0.294 6 to 2.389 9 μg/mL with a mean of 1.084 0 μg/mL.The sensitivity distribution was unimodal,and there was no resistant isolate in P.nicotianae population.The carboxylic acid amide(CAA)fungicides were single-site in action and activity to oomycetes.The synergistic interactions were tested by Wadley method between fluazinam and dimethomorph,flumorph,mandipropamid,respectively.The mixture containing dimethomoph:Huazinam at 1:2 ratio showed additive actions,with the synergy ratio of 1.2.The mixture containing flumorph and fluazinam at 1:5 ratio had the highest synergy ratio(SR 2.07).Mandipropamid and fluazinam had an additive interaction and the proportion of 2:1 had the lowest EC50 value(0.020 7 μg/mL).This study demonstrated the sensitivity of P.nicotianae to fluazinam,and provided the experimental foundation to use fluazinam for tobacco black shank management.展开更多
Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and s...Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and symptoms of this disease include irregular chlorotic lesions on the tips and edges of infected leaves and black punctate fruiting bodies in dead leaf tissues. Given favourable environmental conditions, this disease spread to areas surrounding Gansu. In this study, infected leaves were collected from Gansu and Ningxia Hui Autonomous Region between 2018and 2020 to identify the disease-causing pathogen. Based on morphological features, pathogenicity tests, and multilocus phylogenetic analysis involving internal transcribed spacer(ITS), 18S small subunit rDNA(SSU), 28S large subunit rDNA(LSU), translation elongation factor 1-alpha(TEF), and β-tubulin(TUB) sequences, Eutiarosporella dactylidis was identified as the causative pathogen of this newly discovered leaf blight. Furthermore, an in vitro bioassay was conducted on representative strains using six fungicides, and both fludioxonil and carbendazim were found to significantly inhibit the mycelial growth of E. dactylidis. The results of this study provide a reference for the detection and management of Eutiarosporella leaf blight.展开更多
基金supported by the National Key Research and Development Program of China(2023YFF0805602)the National Natural Science Foundation of China(U21A20186,32171579,32371592 and 32471674)the Natural Science Foundation of Gansu Province,China(23JRRA1029 and 23JRRA1034)。
文摘Plant roots interact with diverse fungi that are essential for maintaining the productivity and sustainability of pasture ecosystems,but how these root-associated fungi(RAF)differ between forage species and how they respond to nutrient enrichment and fungicide application are not well understood.Here,we constructed an 11-year experiment involving fungicide application(with or without)nested within four levels of experimental nitrogen(N)addition treatments in an alpine pasture,and the RAF communities,root traits,tissue nutrients,and shoot biomass of two dominant forage species(Carex capillifolia and Elymus nutans)were analyzed.The RAF community composition showed striking differences between the plant species and was strongly affected by both N addition level and fungicide applications.Fungicide,but not N application,dramatically reduced the RAF richness of all functional guilds in both plant species,and fungicide also simplified the co-occurrence network of the RAF for C.capillifolia.The RAF community correlated strongly with root traits,whereas their relationships became weakened or even vanished at the level of the individual plant species.The importance of RAF to plant nutrients and productivity varied between plant species,with significant contributions in C.capillifolia but not in E.nutans.This is the first report elucidating the long-term effect of fungicides on RAF in alpine pastures,and our findings emphasize the host-specific responses of RAF community structure and function to anthropogenic disturbances.
基金Supported by Natural Science Foundation of Hunan Province(2024JJ8259).
文摘[Objectives]This study was conducted to improve the purification agent combination conditions for QuEChERS and establish a method for detecting the residues of 18 fungicides in animal-derived foods(fish,pork,milk,eggs,and pork liver)using high-performance liquid chromatography-triple quadrupole tandem mass spectrometry.[Methods]The samples were extracted with acetonitrile,purified with 885 mg of magnesium sulfate,150 mg of PSA(ethylenediamine-N-propylsilane silica gel),and 15 mg of GCB(graphitized carbon black),and analyzed using ACQUITY UPLC BEH C 18 as the chromatographic column with a mobile phase of acetonitrile-0.1%formic acid aqueous solution.[Results]The 18 fungicides showed good linearity in the range of 5.00–200.00μg/L,with correlation coefficients(R^(2))greater than 0.991.The limit of quantification(LOQ)was 0.01 mg/kg.The average recoveries ranged from 63.7%to 117.5%,and the relative standard deviations(RSDs)were between 0.22%and 6.33%.[Conclusions]This method is simple,rapid,and highly accurate,and provides technical reference for the detection and risk assessment of fungicides in animal-derived foods.
基金Supported by the Green Plant Protection Project(213010801)the Heilongjiang Province Key Research and Development Plan Project(20232X02 B0502)the Natural Science Foundation of Heilongjiang Province(LH2022C022)。
文摘In recent years,the prevalence of rice sheath blight caused by Rhizoctonia solani has significantly increased in Heilongjiang Province.Chemical control has become the primary control method.To cope with this,a novel mycelium growth rate method was employed to assess the toxicity of 13 fungicides,including a combination of 45%prochloraz and 125 g·mL^(-1)epoxiconazole,against R.solani.Additionally,the resistance of 99 R.solani strains to thifluzamide across various regions was also evaluated.The findings indicated that 75%trifloxystrobin-tebuconazole exhibited the most effective inhibitory effect,with an effective inhibitory medium concentration(EC50)value of 0.0101μg·mL^(-1).The EC50 values for 20%prothioconazole,125 g·mL^(-1)epoxiconazole,24%thifluzamide,and 50%hexaconazole were all less than 10μg·mL^(-1),indicating a better inhibitory effect on R.solani.The strongest synergistic effect was noted in the mixture of prochloraz and epoxiconazole at a 1:2 ratio,resulting in an EC50 value of 2.9917μg·mL^(-1),and a co-toxicity coefficient of 213.38.Among the 34 strains from Harbin City,the average EC50 value was 196.9341μg·mL^(-1)indicating the highest susceptiblility to thifluzamide.Conversely,15 strains from Shuangyashan City exhibited an average EC50 value of 364.7323μg·mL^(-1),reflecting the lowest sensitivity to thifluzamide.The sensitivity baseline EC50 value for R.solani was 253.8854μg·mL^(-1),with an overall resistance level between 0.1567 and 3.3292,indicating that the resistance level of R.solani in Heilongjiang Province remained low.Therefore,R.solani was still sensitive to thifluzamide in most areas of Heilongjiang Province,but there was a certain risk of resistance in Qitaihe City,which needed to be continuously monitored.At the same time,this study might provide a theoretical foundation for enhancing the prevention and management of the rice sheath blight.
基金supported by the National Key Research and Development Program of China(2022YFD1400100)the Jiangsu Agriculture Science and Technology Innovation Fund,China(CX(21)2037)+1 种基金the Guidance Foundation of the Hainan Institute of Nanjing Agricultural University,China(NAUSY-MS03)the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(KYCX20_0596)。
文摘In yeast,the stress-responsive protein Whi2 interacts with phosphatase Psr1 to form a complex that regulates cell growth,reproduction,infection,and the stress response.However,the roles of Whi2 and Psr1 in Fusarium graminearum remain unclear.In this study,we identified homologous genes of WHI2 and PSR1 in F.graminearum and evaluated their functions by constructing deletion mutants.By comparing the responses of the mutants to different stressors,we found that FgWHI2 and FgPSR1 were involved in responding to osmotic,cell wall and cell membrane stresses,while also affecting the sexual and asexual reproduction in F.graminearum.Our studies demonstrated that FgWHI2 and FgPSR1 regulate the biosynthesis of ergosterol and the transcriptional level of FgCYP51C,which is a CYP51 paralogues unique to Fusarium species.This study also found that the deoxynivalenol(DON)production of FgWHI2 and FgPSR1 deletion mutants was reduced by≥90%and DON production was positively correlated with the transcriptional levels of FgWHI2 and FgPSR1.In addition,we observed that FgWHI2 and FgPSR1 were involved in regulating the sensitivity of F.graminearum to chlorothalonil,fluazinam,azoxystrobin,phenamacril,and oligomycin.This study revealed cross-resistance between chlorothalonil and fluazinam.Meanwhile,chlorothalonil and fluazinam inhibited DON biosynthesis by altering the normal expression of FgWhi2 and FgPsr1.Interestingly,the subcellular localization of FgWhi2 and FgPsr1 was significantly altered after treatment with chlorothalonil and fluazinam,with increased co-localization.Collectively,these findings indicate that FgWHI2 and FgPSR1 play crucial roles in stress response mechanisms,reproductive processes,secondary metabolite synthesis,and fungicide sensitivity in F.graminearum.
基金financed by the ministry of science and technology of P.R.China
文摘[Objective] This study was conducted to determine the toxicity of 26 fungicides against Oidium heveae and the synergistic effects of their binary mixtures.[Method] The sensitivity of O.heveae to 26 fungicides was determined in vitro and in vivo by calculating EC50 values.Horsfall＇s toxicity rate was preliminarily employed to predict the type of joint action of 180 two-way mixtures,based on which the interaction level of the potentially synergistic mixtures was validated by Sun and Johnson＇s co-toxicity coefficient.[Result] Triflumizole,pyraoxystrobin,flufenoxystrobin,epoxiconazole,pyrametostrobin,flusilazole,pyraclostrobin and tetraconazole were the most potent inhibitors of both spore germination and mycelial growth.An ‘in vitro-in vivo＇ integrated strategy is proposed for screening the inhibitors of O.heveae,according to the fact that data obtained in germination experiment are able to reflect to some extent the effectiveness of fungicide confirmed by pot experiment.Results achieved by Horsfall＇s were in line with that validated by Sun and Johnson＇s,the Horsfall＇s seems to be a convenient means to assess rapidly the potential interaction type and level of fungicides in a binary mixture.Nineteen mixtures interact synergistically：epoxiconazole ＋ pyraclostrobin at the mixing ratio of 6：4,8：2;tetraconazole ＋ flufenoxystrobin at 1：9,2：8,3：7 and 4：6;triadimefon ＋ flufenoxystrobin at 9：1;triflumizole ＋ flufenoxystrobin at 8：2;flusilazole ＋pyrametostrobin at 7：3,8：2 and 9：1;tetraconazole ＋ pyrametostrobin at 6：4;triadimefon ＋ pyrametostrobin at 5：5,8：2;triflumizole ＋ pyrametostrobin at 7：3,8：2;tetraconazole ＋ pyraoxystrobin at 9：1;triflumizole ＋ pyraoxystrobin at 8：2,9：1.[Conclusion] The single fungicides and their binary mixtures are expected to serve as the alternatives to triadimefon and the alternate use of them could delay the buildup of resistant O.heveae isolate.
基金Supported by Fund of Guizhou Academy of Agricultural Sciences "Study on Pathogenesis and Chemical Control Techniques of Apple Powdery Mildew in Western Guizhou"[QNKH(Fund)No.2010001]Special Project of Guizhou Academy of Agricultural Sciences "Introduction and Demonstration of Apple Three-excellence Technology"[QNKYZX(2009)No.041]~~
文摘[Objective] This study aimed to screen effective fungicide for prevention and control of apple powdery mildew. [Method] Field efficacy of six kinds of fungi- cides with 18 concentrations against apple powdery mildew was investigated. [Re- sult] 4 000-fold triflumizole WP exhibited the highest control efficacy of 82.96%, fol- lowed by 3 000-fold triflumizole WP with control efficacy of 77.75%, while 800-fold and 1 000-fold 70% thiophanate methyl WP exhibited relatively low control efficacy, which was both lower than 60%. [Conclusion] In actual production, 4 000-fold triflu- mizole WP and 3 000-fold triflumizole WP should be used alternately to control and prevent apple powdery mildew.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201303057)948 Program(2011-G4)~~
文摘For exploring the influences of application and residue of chemical fungi- cides on chlamydospore preparations of Trichoderma spp., the effects of seven chemical fungicides on chlamydospore germination and mycelia growth of two bio- control fungi T. harzianum 610 and T. Iongibrachiatum 758 were studied. Carben- dazim, tebuconazole and difenoconazole showed strong toxicities, thiram and car- bexin showed moderate toxicities, and metalaxyl showed Mycelia growth of the two strains was more sensitive to most tested fungicides than those of chlamydospore germination. Chlamydospore germination of 610 was more sensitive to tested fungicides than those of 758, and mycelia growth of 758 was more sensitive to most tested fungi- cides than those of 610. Among the seven fungicides, 98% carbendazim had the strongest effects （ECru values were 1.64 and 0.05μpg/ml）, and 70% pentachloroni- trobenzene had the weakest effects （EC50 values were 1.64 and 0,05 μg/ml） for chlamydospore germination and mycelia growth of 610. As for 758, 98% carbendaz- im had the strongest inhibitory effects and 95% metalaxyl had the weakest inhibitory for chlamydospore germination of 756 （EC50 values were 0.62 and 1 108.61 μg/ml respectively）, whereas 96.2% tebuconazole showed the strongest inhibitory effects for mycelia growth of 758 （EC= value was 0.32μg/ml）, and 95% metalaxyl was the weakest （EC= value was 1 206.29 μg/ml）. According to the applied concentration of different fungicides in practice, we concluded that chlamydospore preparations of 610 and 758 could not be combined with carbendazim, tebuconazole, thiram and carboxin for controlling plant diseases, and the pesticide residues to the biocontrol effects should be kept in mind. Chlamydospore preparations of 610 and 758 can be and difenoconazole for controlling plant dis- eases, 758 chlamydospore preparations and germinated chlamydospore of 610 can be combined with metalaxyl for controlling plant diseases, and pesticide residue risk was not serious.
基金Supported by National Natural Science Fondation of China(31260067)Collegeenterprise Cooperation Project of Yanbian University[(2015)6]~~
文摘[Objective] This study was conducted to screen suitable fungicides to con-trol ginseng leaf blight caused by Alternaria panax_Whetz. [Method] The antifungal activity of seven fungicides against A. panax_ was determined based on mycelial growth rate in vitro. [Result] The results of in vitro antibiotic activity assay showed that there were significant differences in inhibition rate among different concentration treatments of each of the seven fungicides. Toxicity test results showed that among the seven fungicides, difenoconazole had the smal est EC50 （0.61 mg/L）, fol owed by streptomycin and captan, with EC50 value lower than 100 mg/L. [Conclusion] A fungicide which had strong antifungal activity on A. panax was screened out, and the results wil provide a theoretical basis for further field trial.
基金sponsored by the National Natural Science Foundation of China (30971891)the Natural Science Foundation of Jiangsu Province, China(BK2008337)the Anhui Provincial Natural Sci-ence Foundation,China (10040606Q26)
文摘This report reviews the characteristics of JS399-19, a novel cyanoacrylate fungicide. JS399-19 strongly inhibits the mycelial growth of the fungal plant pathogens of the genus Fusarium and exhibits great potential in controlling Fusarium head blight （FHB） on wheat and other cereals. The mode of action of JS399-19 is evidently different from that of benzimidazole （for example, carbendazim） and other sort of fungicides, making it a possible replacement for carbendazim in China to manage carbendazim-resistant subpopulations of Fusarium graminearum and F. asiaticum. JS399-t9 has excellent protective and curative activity against these pathogens. Incorrect use of this fungicide, however, is likely to select for resistance. Among JS399-19-resistant mutants of F. asiaticum induced in the laboratory, the resistant level of mutants was high and the phenotype of resistance against JS399-19 was conferred by a major gene by genetic analysis. The fitness of laboratory-induced JS399-19-resistant mutants of F. asiaticum was nearly equal to that of their parents. JS399-19 lacks cross resistance with other sort fungicides. To control FHB with JS399-19 and to delay the development of the fungicide-resistance, farmers should use tank mixtures containing JS399-19 and carbendazim, metconazole, tebuconazole, or prothioconazole.
文摘[Objective] The aim was to study the effect of three new fungicides against rice sheath blight in field experiment. [Methods] The experiment set up 7 treatments with three times of repetition and designed by random grouping. By using 5 sampling points in each plot, and investigating continuous 4 holes of each point, total plants, diseased plants and disease degrees were recorded. Then disease index and control efficiency were calculated, and variance analysis was carried out. [Results] 300 or 450 ml/hm^2 azoxystrobin ＋ difenoconazole 325 g/L SC had better control efficiency to rice sheath blight and had no phytotoxicity effect, we should use it at the initial disease stage and continuously spray 2-3 times. [Conclusion] The experiment provided a theoretical basis for controlling rice sheath blight using fungicides.
基金Supported by Basic Projects in Yunnan Academy of Agricultural Sciences"Medicinal Plant Resources Nursery Building"~~
文摘[Objective] The research aimed to isolate and identify the pathogen of anthracnose of Ligusticum chuanxiong Hort,and make the antifungal test on four kinds of fungicides for selecting the optimum fungicides.[Method] The pathogenic fungi was separated according to Koch＇s rule and the shape characteristics were identified. The antifungal test of fungicides was made by using plate mycelium growth inhibition method.[Result] The pathogenic fungi was separated from leaves of Ligusticum chuanxiong Hort. and morphological characters were consistent with that of Colletotrichum gloeosporioides. In addition to chloroisobromine cyanuric acid,the other three fungicides could inhibit the mycelium growth. The growth inhibition rates of 1 000 times Metalaxyl＋mancozeb,zineb,Thiophanate-methyl for the mycelium were 26.8%,22.1%,59.8% respectively after 7 days.[Conclusion] The anthracnose was caused by Colletotrichum gloeosporioides. Ligusticum chuanxiong Hort. was a new record host plant of Colletotrichum gloeosporioides and the best inhibiting fungicide was Thiophanate methyl.
基金Supported by Agricultural S&T Innovation:Genetic Structure Analysis and Parasitism Fitness of U.virens in Anhui Province(14B1148)Special Fund for Talent Development:Pesticide Innovation and High-efficient Application Technology(13C1109)~~
文摘[Objective] This study aims to screen for the high effective fungicides which could significantly decrease the disease incidence and disease index of rice false smut. [Method] The inhibitory activities of the fungicide against mycelial growth of Ustilaginoidea virens were measured to in vitro evaluate the ECho values. And 17 fungicides were sprayed to evaluate the efficacy and effect of the fungicides tested in the field trials on the rice characters, [Result] The results showed that epoxicona- zole, difenoconazole, propiconazole and procloraz exhibited high inhibitory activity against mycelial growth of Ustilaginoidea virens with the ECso values 0.04, 0.07, 0.12 and 0.11 pg/ml, respectively. The results of field trials showed that the efficacy of Wen- quning, and fungicides such as difenoconazole, prochloraz, propiconazole, epoxi- conazole and their mixtures in controlling rice false smut were all 70% or more. [Conclusion] The 17 tested fungicides behaved efficacy in controlling rice false smut and did not cause drug injury on leaves and grains of rice plants, sprayed when flag leaves of rice fully expanded.
基金Supported by Key R&D Program of Shandong Province(2018GNC110013)the Innovative Project of Forestry Science and Technology of Shandong Provinc of China(LYCX04-2018-23)Agricultural Improved Seed Project of Shandong Province(2016LZG012)
文摘In this research,the inhibitory effect of 16 fungicides on Colletotrichum horri causing persimmon anthracnose was investigated using mycelial growth method and spore germination method. The results showed that among the 16 tested fungicides,10% of Difenoconazole WG,33. 5% of Copper quinolate SC,25%of Bromothalonil EC,70% of Mancozeb WP,430 g/L of Tebuconazole SC,50% of Prochloraz-manganese chloride and 400 g/L of Flusilazole EC achieved the best inhibitory effect on mycelial growth of C. horri,with the inhibition rate of 100%; 70% of Polyram WG,33. 5% of Copper quinolate SC,25% of Bromothalonil EC,70% of Mancozeb WP,50% of Chlorobromoisocyanuric acid AF,50% of Triram WP and 400 g/L of Flusilazole achieved the best inhibitory effect on spore germination of C. horri,with the germination rate of 0. In conclusion,33. 5% of Copper quinolate SC,25% of Bromothalonil EC,70% of Mancozeb WP and 400 g/L of Flusilazole EC achieved the best inhibitory effect both in mycelial growth and spore germination,which could be used as the preference fungicides for the control of persimmon anthracnose,and 70% of Polyram WG and 50% of Triram WP achieved the secondly best inhibitory effect,which could be used as alternative fungicides. The results of this research could provide scientific evidence for the effective control of persimmon anthracnose,and more optional pesticides for utilization in the production practice of persimmon industry.
文摘[Objective] This study aimed to investigate the resistance to different fungicides in Phytophthora parasitica var. nicotianae. [Method] Under indoor incubation conditions, the resistance to dimethomorph, metalaxyl-mancozeb, propamocarb and ovraclostrobin.dimethomorph in P. parasitica strain isolated from Zhenyuan County in Qiandongnan State was analyzed with colony growth measurement method. [Result] P. parasitica exhibited different levels of sensitivity to four fungicides. To be specific, P. parasitica exhibited the highest resistance to dimethomorph, and ECho reached 1.19 μg/ml. [Conclusion] In Zhenyuan tobacco-growing area, long-term single use of dimethomorph possesses certain resistance risk in prevention and control of black shank disease.
基金supported by the National Natural Science Foundation of China (No.30600082,20777089)the "Knowledge Innovation" Program of Chinese Academy of Sciences (No.kzcx1-yw-06-03)the Key Technologies R&D Program of China (No.2008BADA7B01)
文摘Fungicides have been used extensively for controlling fungal pathogens of plants. However, little is known regarding the effects that fungicides upon the indigenous bacterial communities within the plant phyllosphere. The aims of this study were to assess the impact of fungicide enostroburin upon bacterial communities in wheat phyllosphere. Culture-independent methodologies of 16S rDNA clone library and 16S rDNA directed polymerase chain reaction with denaturing gradient gel electrophoresis （PCR-DGGE） were used for monitoring the change of bacterial community. The 16S rDNA clone library and PCR-DGGE analysis both confirmed the microbial community of wheat plant phyllosphere were predominantly of the γ-Proteobacteria phyla. Results from PCR-DGGE analysis indicated a significant change in bacterial community structure within the phyllosphere following fungicide enostroburin application. Bands sequenced within control cultures were predominantly of Pseudomonas genus, but those bands sequenced in the treated samples were predominantly strains of Pantoea genus and Pseudomonas genus. Of interest was the appearance of two DGGE bands following fungicide treatment, one of which had sequence similarities （98%） to Pantoea sp. which might be a competitor of plant pathogens. This study revealed the wheat phyllosphere bacterial community composition and a shift in the bacterial community following fungicide enostroburin application.
基金Financial support by the German Research Foundation (DFG) (SCHW750/9) in the frame of the Priority Program SPP 1315。
文摘The proportion of organic matter and mineral composition are important factors determining the formation and type of non-extractable residues(NERs) of pesticides in soil. In this study, we investigated the enantioselectivity in degradation and NER formation of the chiral fungicide metalaxyl in soil particle size fractions(silt and clay). Microbial and extracellular enzyme activities during these processes were monitored in incubation of silt and clay samples isolated from sterilized and non-sterilized soil samples collected from a long-term agricultural field experimental site in Ultuna, Sweden. The temporal influence on the fate of the fungicide was noted by short-term(10-d) and long-term(92-d) incubations. Besides the acquisition of quantitative data with gas chromatography-mass spectrometry(GC/MS), stereoselective analyses were performed with chiral GC/MS. Quantitative results pointed to a higher metabolism rate of the pesticide through microbial activity than through extracellular enzyme activity. This was also confirmed by the enantioselective depletion of R-metalaxyl and the subsequent formation of R-metalaxyl acid in microbially active samples from non-sterilized soil. The silt fraction containing a high amount of organic matter exhibited a significant hydrolyzable proportion of metalaxyl NERs that was releasable under alkaline conditions. On the contrary, the clay fraction showed an enhanced affinity for covalently bound residues. Based on our results, we recommend differentiating between reversibly and irreversibly bound proportions of pesticides in persistence and environmental risk assessment because the reversible fraction contained potentially bioavailable amounts of residues that may be released under natural conditions.
文摘The effects of biofungicide formula containing the biocontrol agent Trichoderma harzianum (Jn14) as wettable powder in combination with the fungicides pyrimethanil and a mixture of cyprodinil and flydioxonil on Botrytis cinerea of strawberry in vitro, in vivo and in greenhouse were studied. The pathogen B. cinerea was more affected in vitro by low concentrations of the fungicides tested above 0.4 μg·ml-1 than the bioagent T. harzianum (Jn14). The later was almost insensitive to pyrimethanil. In the same direction, gray mould disease severity on strawberry detached leaves and whole plants was reduced up to 89% by the tested fungicides, compared to the control, while the application of T. harzianum (Jn14) alone reduced disease severity up to 45% on strawberry detached leaves, compared to the control. In the integrated control approach, the combination of T. harzianum (Jn14) with higher concentrations of the tested fungicides (ED50) completely inhibited strawberry gray mould disease severity in pots and the greenhouse.
基金supported by Cooperation Project between China and Poland Government of Ministry of Science and Technology of China(AM30:001(30-20))the National Natural Science Foundation of China(30370911).
文摘Two seed lots of lettuce (Lactuca sativa L.) cv. Krlowa Majowych were primed in polyethylene glycol (PEG) 8000 at -1.25MPa for 7 days in dark at 20C. Two fungicide treatments combined with PEG were used to control fungi: 1) Funaben T(0.1%) and Apron 35 SD (0.02%) were added to -1.25 MPa PEG solution (PEG+F); 2) After seed priming and drying,Funaben T was mixed at 5 g kg-1 and Apron 35 SD at 1 g kg-1 of seeds (PEG then F dust). PEG, PEG+F and PEG then F dusttreatments reduced significantly thermodormancy and increased the seed germination at 35C in both lots. PEG then Fdust treatment had the best effect on reducing seed thermodormancy at 35C, and increased seed germination to 64.5% inlot 1 and 72.0% in lot 2 compared to 0 in untreated. PEG and PEG then F dust treatments have accelerated germinationspeed at 20 and 15C in both lots. There was a significant reduction in seed infestation in which the seeds were treatedwith PEG+F and PEG then F dust compared to untreated seeds and PEG primed seeds. PEG priming enhanced seedinfestation considerably by Alternaria alternata, Penicillium spp., Rhizopus spp. and Ulocladium spp. Mycologicalanalysis showed higher frequency of Alternaria alternata and Ulocladium spp. in untreated seeds at 20C. Priming incombination with fungicides significantly alleviated the infestation of fungi, especially Alternaria alternata infestation.
文摘Tobacco black shank caused by Phytophthora parasitica var.nicotianae(Breda de Hean)is one of the most serious diseases in tobacco growing,and few effective fungicides are available currently.The purpose of this study was to assess the feasibility of using fluazinam to treat tobacco black shank disease.In vitro toxicities of fluazinam to 62 isolates of P.nicotianae were determined by mycelial growth rate method.The EC50 values ranged from 0.294 6 to 2.389 9 μg/mL with a mean of 1.084 0 μg/mL.The sensitivity distribution was unimodal,and there was no resistant isolate in P.nicotianae population.The carboxylic acid amide(CAA)fungicides were single-site in action and activity to oomycetes.The synergistic interactions were tested by Wadley method between fluazinam and dimethomorph,flumorph,mandipropamid,respectively.The mixture containing dimethomoph:Huazinam at 1:2 ratio showed additive actions,with the synergy ratio of 1.2.The mixture containing flumorph and fluazinam at 1:5 ratio had the highest synergy ratio(SR 2.07).Mandipropamid and fluazinam had an additive interaction and the proportion of 2:1 had the lowest EC50 value(0.020 7 μg/mL).This study demonstrated the sensitivity of P.nicotianae to fluazinam,and provided the experimental foundation to use fluazinam for tobacco black shank management.
基金supported by the Doctor Foundation of Gansu Academy of Agricultural Sciences,China(2020GAAS33)the Young Science and Technology Lifting Engineering Talents in Gansu Province,China(2020-18)the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2017-ICS)。
文摘Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and symptoms of this disease include irregular chlorotic lesions on the tips and edges of infected leaves and black punctate fruiting bodies in dead leaf tissues. Given favourable environmental conditions, this disease spread to areas surrounding Gansu. In this study, infected leaves were collected from Gansu and Ningxia Hui Autonomous Region between 2018and 2020 to identify the disease-causing pathogen. Based on morphological features, pathogenicity tests, and multilocus phylogenetic analysis involving internal transcribed spacer(ITS), 18S small subunit rDNA(SSU), 28S large subunit rDNA(LSU), translation elongation factor 1-alpha(TEF), and β-tubulin(TUB) sequences, Eutiarosporella dactylidis was identified as the causative pathogen of this newly discovered leaf blight. Furthermore, an in vitro bioassay was conducted on representative strains using six fungicides, and both fludioxonil and carbendazim were found to significantly inhibit the mycelial growth of E. dactylidis. The results of this study provide a reference for the detection and management of Eutiarosporella leaf blight.
