Effect of Tebuconazole exposure on oral Atenolol absorption in rats,based on bile acid homeostasis

Objective:This study is aimed to explore the effect of triazole fungicide tebuconazole(TEB)exposure on the oral absorption behavior of atenolol(AT),based on the homeostasis of bile acids(BAs).Methods:TEB was daily gavaged to rats with 3 mg/kg dose for 28 days to establish the TEB-exposure rat model.The amounts of glycocholic acid,glycochenodeoxycholic acid,taurocholic acid and taurine deoxycholic acid in the small intestine contents of normal and TEB-exposure rats were detected by LC-MS/MS.AT(10 mg/kg)were gavaged to the normal and TEB-exposure rats,and then blood were collected from orbital venous plexus at predetermined time-points.The concentration of AT in plasma was detected by LC-MS/MS,and the pharmacokinetic parameters were calculated by the DAS pharmacokinetic software.An intestinal circulation perfusion model was established in normal rats,and perfused with the perfusates containing the model drug of fluorescein and the BAs with the same compositions as the normal/TEB-exposure rats.After perfusion,the absorption and permeability of fluorescein in intestine were detected,as well as the oxidative stress status and ZO-1 expression level in the intestinal tissues.Results:Compared with normal rats,TEB-exposure increased the amounts of glycocholic acid,glycochenodeoxycholic acid,taurocholic acid and taurine deoxycholic acid in intestine significantly(P<0.001).In TEB-exposure rats,the maximum plasma concentration and area under the curve of AT were increased significantly than those of normal rats(P<0.05),and the peak time was significantly delayed(P<0.05).The TEB-induced BAs homeostasis perturbance increased intestinal permeability,and this effect was associated with the elevation of oxidative stress and the down-regulation of intercellular tight junction proteins in intestinal tissues.Conclusion:TEB-exposure can affect the oral absorption behavior of AT,which is probably related with the intestinal BAs homeostasis perturbance,thus it might affect the clinical efficacy and safety of this drug.

Synergism and Field Efficacy of Mixed Preparations of Pyraclostrobin and Tebuconazole to Glomerella cingulata

[Objective] This study was conducted to screen high-efficient low-toxicity new compound preparation for control of Glomerella cingulata. [Method] The toxicity of pyraclostrobin, tebuconazole and their mixed preparations to Glomerella cingulata was determined by mycelial growth rate method, and their control effects on Glomerella cingulata were evaluated by field efficacy test. [Result] The mixed preparations of pyraclostrobin and tebuconazole at mass ratios of 5：1, 3：1, 1：1, 1：3 and 1：5 exhibited ECso values to mycelial growth of Glomerella cingulata of 0.612 9, 0.530 1, 0.232 6, 0.232 8 and 0.329 6 iJg/ml, respectively; and the 5 preparations exhibit- ed synergistic coefficients （SRs） to Glomerella cingulata of 1.29, 1.33, 2.29, 1.84 and 1.22, respectively, and among them, the preparation with mass ratio of 1：1 showed the highest synergism. The field efficacy test showed that the field control effects of 1 000 times, 2 000 times and 3 000 times dilutions of 25% pyraclostrobin-tebuconazole suspension, 5 000 times dilution of 430 g/L tebuconazole suspension and 2 000 times dilution of 250 g/L pyraclostrobin EC were 91.54%, 90.80%, 82.88%, 76.43% and 74.10%, respectively. [Conclusions] Therefore, the mixed preparations of pyraclostrobin and tebuconazole showed remarkable synergism on control of Glomerella cingulata, and preparation with the mixing ratio of 1：1 exhibited the most significant synergism on Glomerella cingulata. For soaking treatment to fruit clusters with 1 000-2 000 times dilution of 25% pyraclostrobin .tebuconazole suspension, the field efficacy to Glomerella cingulata was over 90%.

Control of Maize Head Smut with 6% Tebuconazole FS

In order to test the control effect of 6% tebuconazole FS on maize head smut and to select its optimal dose for mixing seed, field tests were performed in 2012 and 2013. The results showed that 6% tebuconazole FS was effective to control maize head smut, and the control effect ranged from 73.4% to 91.1%. In addition, it also improved the maize yield by 36.7%-44.1%, compared with the blank control. The optimal dose of 6% tebuconazole FS for seed dressing was 166.5 g/100 kg to control head smut on maize.

Inhibitory Effects of Phenamacril, Tebuconazole and Their Mixtures on Fusarium graminearum in Wheat

Fusarium head blight caused by Fusarium graminearum is one of the most serious diseases in wheat production worldwide, which seriously affects the yield and quality of wheat. Wheat grains carrying the pathogen are poisonous to human and livestock health. With the long-term use of single chemical pesticide, the drug-resistance of F. graminearum is increasing day by day, and mixed agent is one of the effective strategies to improve the efficacy and delay the resistance. The mycelial growth rate method was used to determine the inhibition rates of phenamacril, tebuconazole and their mixtures(1∶1, 1∶3, 1∶5, 1∶7, 3∶1, 5∶1 and 7∶1). The synergistic coefficient(SR) was calculated by Wadley method, and the combined action types of the two agents were evaluated. The results showed that the ECof tebuconazole was 0.418 28 mg/L, and that of phenamacril was 0.489 8 mg/L; the optimum mixture ratio of phenamacril and tebuconazole was 1 ∶1, with the ECvalue of 0.053 74 and the synergistic coefficient of 4.2696, and the control effect of mixed agent was significantly better than that of single agent. It is feasible to control Fusarium head blight by mixing phenamacril and tebuconazole, providing a theoretical basis for development of new compound agents and effective control of Fusarium head blight.

Inhibition Effect and Synergistic Effect of Prochloraz and Tebuconazole and Their Mixture on Fusarium graminearum

Wheat scab caused by Fusarium graminearum is increasingly severe in the middle and lower reaches of the Yangtze River region. With long-term use of single chemical pesticide,the drug resistance of F. graminearum is growing day by day. In order to reveal the inhibition effect and synergistic effect of prochloraz and tebuconazole and their mixture on F. graminearum,new compound agents for controlling wheat scab were developed. The inhibition effect and synergistic effect of prochloraz and tebuconazole mixed at seven different ratios on F. graminearum were studied. The results showed that the efficiency of the mixture was the best when the proportion of prochloraz and tebuconazole was 1:7; the EC50 was 0.145 36 and the synergistic coefficient was 1.853 9. The results provide a theoretical basis for development of new compound agents and effective control of wheat scab.

Determination of Tebuconazole Residue in Apples and Vegetables by Matrix Solid Phase Dispersion-Gas Chromatography

[ Objective] The study aimed to determine tebuconazole residue in apples and vegetables using matrix solid phase dispersion-gas chro- matography （MSPD-GC）. [ Method] The effects of extraction and determination conditions on the detection of tebuconazole left in apples and veg- etables were analyzed, and the optimum extraction conditions were determined. [ Result] The recovery rate of tebucenazole was the highest when the ratio of a sample to florisil dispersant was 1 ： 4, and the mixture of hexane and acetone （ 1 ： 1 ） with total volume of 8 ml was as the eluant. Under the optimum conditions, the relative standard deviation （RSD） of the method was 4.9% -7.6%, and the detection limit was 0.1 tJg/g, while the re- covery rate of tebuconazole changed from 86.7% to 95. 2% . [ Conclusion] The method was simple, accurate, sensitive and applicable to the de- termination of tebuconazole in aaricultural Droducts.

Application Technology of Tebuconazole WG against Sheath Blight 75% Trifloxystrobin · Rice Blast and Rice

[ Objective] The paper was to confirm the best application period and frequency of 75% trifloxystrobin ·tebuconazole WG against rice blast and rice sheath blight. [ Method] Influences of different dosages and different application periods of 75% trifloxystrobin · tebuconazole WG on control effects against rice blast and rice sheath blight, as well as their effects on rice yields were studied in the paper. [Result] The control effects of three different fungicides application treatments against rice sheath blight were 80.24%, 83.0% and 67.99%, and the control effects against rice blast were 56.4%, 49.11% and 61.1%, respective- ly. Advanced application of fungicide for two times had good prevention effect against rice sheath blight ; properly delayed application of fungicides for two times was conducive to improving the control effect against rice blast, and one time application of sufficient fungicide during middle booting stage had higher control effect than application for two times. Effective panicle number per unit area, total grain number, 1 000-grain weight and moisture content of various fungicide application treat- ments did not have significant difference with those of the treatments without fungicide application, but grain number per panicle in treatments applied with fungicide was higher than the treatment without application. [ Conclusion] 75% Trifloxystrobin ·tebuconazole WG has better control effect on rice blast and sheath blight, which helps to promote the formation of rice grain and increases yield significantly. The fungicide application against rice sheath blight should be appropriately ad- vanced, and application for one time against panicle blast after middle booting stage is helpful to improve the control effect.

海南省稻瘟病菌对戊唑醇的敏感性及抗性菌株适合度

通过检测海南省稻瘟病菌对戊唑醇的敏感性及抗性菌株的适合度,了解海南省稻瘟病菌对戊唑醇的抗药性风险,为该杀菌剂的科学使用及抗性治理提供理论依据和策略。采用菌丝生长速率法测定2022年采集分离自海南省的144株稻瘟病菌株对戊唑醇的敏感性,根据菌株的敏感性频率分布,建立海南省稻瘟病菌对戊唑醇的敏感基线。选取敏感基线建立过程中测得的有效抑制中浓度(EC_(50))较低的敏感菌株15个,在连续选择压下进行抗药性驯化,对驯化出的菌株进行抗性水平划分,并测定抗性菌株的遗传稳定性及其对戊唑醇与杀菌剂吡唑醚菌酯、氟环唑、咪鲜胺、苯醚甲环唑、烯唑醇之间的交互抗性以及适合度。结果表明,供试144株菌株的EC_(50)值在0.176 9~0.998 0μg/mL,其中最不敏感菌株的EC_(50)值是最敏感菌株的5.64倍,EC_(50)平均值为(0.476 3±0.174 5)μg/mL。菌株的敏感性频率呈连续性单峰曲线分布,海南省稻瘟病菌对戊唑醇的敏感基线为0.476 3μg/mL。通过对15株敏感菌株进行药剂驯化共获得2株抗性菌株,其EC_(50)值分别为1.289 5μg/mL和1.868 4μg/mL,抗性倍数分别为5.38倍和6.65倍,均属低抗性水平。将上述2株抗性菌连续转接8代后,其始终保持低水平抗性。通过测定吡唑醚菌酯、氟环唑、咪鲜胺、苯醚甲环唑、烯唑醇对戊唑醇抗性菌株及亲本菌株的EC_(50)值并进行对比,结果显示,戊唑醇在对海南省稻瘟病菌的防治上与上述药剂均不存在交互抗性。对戊唑醇抗性菌株的离体适合度进行测定发现,相比于亲本菌株,2株抗性菌株的菌丝生长速率显著降低,且孢子产量均出现不同程度下降。此外,其对强酸和强碱环境更加敏感,致病力也大大减弱。因此,海南省稻瘟菌株对戊唑醇产生抗药性突变的频率较低,其抗性菌株的环境适合度显著下降,抗药性风险较低。此外,海南省稻瘟病菌对戊唑醇与常用杀菌剂无交互抗药性,可在生产上通过交互轮换使用或与多作用位点保护剂混合使用等策略来延缓抗药性的产生。

空心菜对戊唑醇的吸收与富集特征

为了研究空心菜对戊唑醇吸收与富集作用,通过水培试验分析空心菜对水中三唑类杀菌剂戊唑醇去除效率以及戊唑醇在空心菜体内的富集与转运特征,评价其对戊唑醇污染环境的植物修复能力。结果表明:戊唑醇在空心菜种植的培养液中的消解速率明显快于无空心菜种植的培养液。在3个不同初始处理浓度(1、10、100μg·L^(–1))戊唑醇培养液中,处理10 d后空白对照组去除率几乎为0%,而空心菜处理组的去除率均大于85%,3个浓度处理组戊唑醇的消解半衰期分别为3.47、2.46和2.49 d。空心菜根和茎叶部位的富集行为具有较大差异,其生物富集量和生物富集系数均为根部>茎叶部,且茎叶部分的转运系数均小于1,表明戊唑醇很难在空心菜植株中向上迁移,易被根部富集,可见空心菜具有较好的修复戊唑醇污染水体的潜力。研究结果可为戊唑醇环境污染植物修复以及农业生产中合理用药提供数据支撑。

防治橡胶树褐根病0.5%戊唑醇膏剂的研制

由木层孔菌属有害层孔菌Phellinus noxius Corner引起的褐根病是我国橡胶树的主要根部病害之一。生产上常用挖隔离沟和灌根施药方式进行防治,但其耗费人力物力,防治成本高。为了寻求经济高效且环保的新技术,本研究通过对不同杀菌剂、填料、增稠剂、渗透剂和保湿剂进行筛选,制备了一种防治橡胶树褐根病的膏剂。随后,通过对外观、附着性、黏度、pH值、稳定性、成膜性及固含量流失率等性能指标的综合评价,确定了膏剂的最佳配方为:0.5%(质量分数,余同)戊唑醇、20%纳米硅藻土、2%羧甲基纤维素钠、6%乌迪尔树皮穿透剂、5%凡士林、5%棕榈油、5%乙二醇,余量为水。制备的膏剂为乳白色黏稠状,呈弱碱性,附着性强,黏度高,冷热储合格,成膜薄且有韧性,膜的固含量流失率为13.95%,耐雨水冲刷能力强。0.5%戊唑醇膏剂经过橡胶植株茎基部施药,通过气相色谱-串联质谱(GC-MS/MS)结合QuEChERs法检测橡胶根中戊唑醇的含量。结果表明,施药后24 h即可在植株根部检测到戊唑醇,96 h含量达到5.49 mg/kg,说明戊唑醇能穿透茎部树皮向下传导至根部。综上所述,膏剂剂型的研制为橡胶树褐根病的化学防治提供了一种新途径。

40%吡唑萘菌胺·戊唑醇悬浮剂对柑橘沙皮病的防治效果

为筛选出安全高效的柑橘沙皮病防治药剂,对新型复配剂40%吡唑萘菌胺·戊唑醇悬浮剂在柑橘沙皮病防治中的效果及其适宜使用剂量进行探讨。通过2021—2022年的田间药效试验发现40%吡唑萘菌胺·戊唑醇悬浮剂对柑橘沙皮病具有较好的防治效果。2021年施药处理3次后,40%吡唑萘菌胺·戊唑醇悬浮剂200 mg/kg对柑橘叶片和果实沙皮病的防治效果分别为79.60%和77.97%,2022年施药处理3次后,40%吡唑萘菌胺·戊唑醇悬浮剂200 mg/kg对柑橘叶片和果实沙皮病的防治效果分别为81.65%和76.37%,防治效果显著优于对照药剂20%吡唑萘菌胺可湿性粉剂和430 g/L戊唑醇悬浮剂。40%吡唑萘菌胺·戊唑醇悬浮剂对柑橘安全、高效,值得应用于柑橘沙皮病防治的示范与推广。

气相色谱-串联质谱法测定小麦中氟嘧菌酯和戊唑醇的残留量

建立了气相色谱-串联质谱(GC-MS/MS)测定小麦中氟嘧菌酯、氟嘧菌酯Z体和戊唑醇残留量的分析方法。样品中氟嘧菌酯、氟嘧菌酯Z体和戊唑醇用乙腈提取,提取液经分散固相萃取净化,以HP-5ms色谱柱分离,GC-MS/MS多反应监测(MRM)模式测定,外标法-溶剂标准曲线法定量。结果表明:5~500 ng/mL质量浓度范围内,氟嘧菌酯、氟嘧菌酯Z体和戊唑醇的峰面积与质量浓度之间呈现出良好线性关系;氟嘧菌酯、氟嘧菌酯Z体和戊唑醇在小麦籽粒、小麦秸秆中的最低检测浓度均为0.02 mg/kg。在添加浓度为0.02~10 mg/kg,氟嘧菌酯、氟嘧菌酯Z体和戊唑醇在小麦籽粒中的平均回收率为92%~104%,相对标准偏差为1.1%~15.3%;氟嘧菌酯、氟嘧菌酯Z体和戊唑醇在小麦秸秆中的平均回收率为88%~106%,相对标准偏差为1.4%~10.9%。该方法具有精密度好、灵敏度和准确度高、杂质干扰少等特点,符合农药残留检测分析的基本要求。

中空介孔二氧化硅负载戊唑醇纳米缓释颗粒的制备及生物活性

本研究以中空介孔纳米二氧化硅(hollow mesoporous nano silica, HMS)为载体负载戊唑醇(tebuconazole, Teb),制备了戊唑醇@中空介孔纳米二氧化硅(Teb@HMS)缓释颗粒。通过扫描电镜(SEM)、透射电镜(TEM)、傅立叶变换红外光谱仪(FTIR)、比表面积分析仪(BET)及热重分析仪(TGA)等仪器对其形貌、结构与性能进行了表征。通过高效液相色谱(HPLC)分析研究了戊唑醇在缓释颗粒中的释放行为。通过菌丝生长速率法、盆栽试验和田间防效试验测定了Teb@HMS缓释颗粒对立枯丝核菌的抑制活性及对水稻纹枯病的防治效果。通过水稻种子发芽试验和斑马鱼试验对Teb@HMS的安全性进行了评价。结果表明:所制备的纳米二氧化硅载药粒子呈规整的中空介孔结构,对戊唑醇的载药率为52.02%,缓释时间长达400 h;Teb@HMS缓释颗粒降低了戊唑醇对非靶标生物水稻种子及斑马鱼的毒性,抑菌活性明显优于戊唑醇原药;盆栽和田间试验结果显示,施药后第18天Teb@HMS针对水稻纹枯病的保护作用防效分别达61.79%和70.42%。该研究可为中空介孔纳米二氧化硅缓释颗粒在农药减量化和植物病害绿色可持续防控方面提供技术支撑和理论指导。

Cardiac energy metabolism disorder mediated by energy substrate imbalance and mitochondrial damage upon tebuconazole exposure

Tebuconazole exposure has been described as an increasing hazard to human health.An increasing number of recent studies have shown a positive association between tebuconazole exposure and cardiovascular disease risk,which is characterized by the reduction of adenosine triphosphate(ATP)synthesis.However,researches on the damage of tebuconazole exposure to energy metabolism and the related molecular mechanisms are limited.In the present study,male C57BL/6 mice were treated with tebuconazole at different low concentrations for 4 weeks.The results indicated that tebuconazole could accumulate in the heart and further induce the decrease of ATP content in the mouse heart.Importantly,tebuconazole induced an obvious shift in substrate utilization of fatty acid and glucose by disrupting their corresponding transporters(GLUT1,GLUT4,CD36,FABP3 and FATP1)expression,and significantly repressed the expression of mitochondrial biogenesis(Gabpa and Tfam)and oxidative phosphorylation(CS,Ndufa4,Sdhb,Cox5a and Atp5b)related genes in a dosedependent manner.Further investigation revealed that these alterations were related to the IRS1/AKT and PPARγ/RXRαpathways.These findings contribute to a better understanding of triazole fungicide-induced cardiovascular disease by revealing the key indicators associated with this phenomenon.

油菜核盘菌(Sclerotinia sclerotiorum)对戊唑醇的抗药性风险评估

为明确油菜核盘菌(Sclerotinia sclerotiorum)对杀菌剂戊唑醇的抗药性风险,通过生长速率法测定了119株核盘菌对戊唑醇的敏感性基线,通过紫外诱导结合药剂筛选获得2株抗药性菌株,开展了抗药性遗传稳定性、菌丝生长速率、产菌核能力、致病力、靶基因序列分析及表达量测定等研究。结果显示:119株油菜核盘菌对戊唑醇的EC50值范围为0.0121~0.8907μg/mL,平均值为0.2403±0.1365μg/mL,呈单峰曲线分布,未发现田间抗药性菌株;经室内诱导获得2株抗药性菌株19AH-5A、19AH-5C,对戊唑醇的EC50值分别是野生型敏感菌株的5.857和12.903倍;此外,抗药性菌株19AH-5C的生物学特性与敏感菌株无显著差异,而19AH-5A的致病力下降严重;2株抗药性菌株中戊唑醇靶标蛋白的编码基因CYP51的碱基序列与敏感菌株完全一致,未发现可引起氨基酸改变的碱基突变,但在戊唑醇培养条件下,抗药性菌株19AH-5C中靶基因CYP51的表达量显著上调3.72倍。油菜核盘菌在戊唑醇选择压力下可产生抗药性菌株,根据119株核盘菌的敏感性基线以及抗性菌株的环境适合度研究结果判断,油菜核盘菌对戊唑醇存在中等抗药性风险,因此使用戊唑醇防治油菜菌核病时应持续开展病原菌抗药性水平监测,同时可将不同作用类型杀菌剂交替使用以延缓田间抗药性的发生。

2种杀菌剂对茉莉根际土壤酶活性和微生物碳源代谢多样性的影响

本研究在人工温室大棚条件下,以白绢病染病茉莉植株根际土壤为材料,分析比较2种杀菌剂(氟啶胺和戊唑醇)处理对土壤理化性质、土壤酶活性及土壤微生物群落碳源代谢多样性的影响。结果表明:在2种不同浓度杀菌剂处理前后,茉莉根际土壤理化性质各项指标具有显著差异。50%氟啶胺处理后,土壤pH和有机质含量分别降低14.8%和18.8%,而50%戊唑醇处理后,有机质含量则显著增加,增幅高达76.8%;50%戊唑醇对土壤全氮、有效磷、速效钾的影响最为显著,其中,全氮最高增幅为77.8%;有效磷最高增加了1.3倍;速效钾最高增幅达2.1倍。杀菌剂对茉莉根际土壤蔗糖酶、脲酶、酸性磷酸酶活性具有显著影响。50%氟啶胺处理后,蔗糖酶活性显著降低92.8%;50%戊唑醇处理后,脲酶活性显著降低,较喷施前减少41.9%;杀菌剂处理后酸性磷酸酶活性均呈递增的变化趋势。比较2种杀菌剂处理后土壤微生物群落的碳源代谢多样性发现,CK的平均每孔颜色变化率(AWCD)最低,2种杀菌剂处理后,AWCD均降低,且戊唑醇对AWCD的抑制作用最显著。总体上,杀菌剂处理后,土壤微生物Shannon-Wiener多样性指数(H)与McIntosh均匀度指数(U)均呈下降趋势,各处理间的Simpson优势度指数(D)无显著差异;土壤微生物群落对6类碳源的代谢能力具有一定的抑制作用。土壤微生物群落碳源利用能力的主成分分析表明,氨基酸类和碳水化合物2类碳源的利用率相似,多聚物类和羧酸类相似。本研究结果可为评估杀菌剂处理后茉莉根际土壤微生物的生态功能提供科学依据。

45%戊唑醇·咪鲜胺水乳剂对苹果炭疽病的田间防治效果

为了丰富苹果炭疽病用药种类,加强药剂轮换,降低抗药性风险,2020~2021年采用田间试验方法,以430 g/L戊唑醇悬浮剂3000倍液(有效成分用量143.3 mg/kg)、45%咪鲜胺水乳剂1000倍液(有效成分用量450 mg/kg)和80%福·福锌可湿性粉剂500倍液(有效成分用量1600 mg/kg)为药剂对照,以清水处理为空白对照(CK),对45%戊唑醇·咪鲜胺水乳剂2000倍液、1500倍液和1000倍液(对应的有效成分用量分别为225、300和450 mg/kg)处理的苹果炭疽病防治效果进行了评价。结果表明:试验用量条件下,45%戊唑醇·咪鲜胺水乳剂对苹果炭疽病的防效较好,其中1000倍液和1500倍液处理的防效均超过90%,二者差异不显著;2000倍液处理的防效接近90%。45%戊唑醇·咪鲜胺水乳剂3种用量处理的防效均高于430 g/L戊唑醇悬浮剂和45%咪鲜胺水乳剂2种单剂处理。45%戊唑醇·咪鲜胺水乳剂2000倍液的防效与防治苹果炭疽病常用药剂80%福·福锌可湿性粉剂500倍液的防效相当;而1000倍液和1500倍液的防效高于80%福·福锌可湿性粉剂500倍液。45%戊唑醇·咪鲜胺水乳剂各用量处理均未观察到药害发生,对有益生物无不良影响。推荐使用45%戊唑醇·咪鲜胺水乳剂防治苹果炭疽病,有效成分用量225~300 mg/kg为宜,可大面积推广应用。

苯醚菌酯与戊唑醇混剂对小麦赤霉病菌的联合毒力及田间防效

为探明苯醚菌酯与戊唑醇混剂对小麦赤霉病菌的联合毒力及对赤霉病、小麦籽粒DON毒素和白粉病的田间防效,开发防治赤霉病的新药剂,采用菌丝生长速率法分别检测了苯醚菌酯、戊唑醇及其11种配比混剂对赤霉病菌的毒力,并进行了最佳配比制剂的田间药效试验。结果表明,苯醚菌酯与戊唑醇配比为1:9时增效系数为2.0804,增效作用最显著。田间药效试验中,37%苯醚菌酯∙戊唑醇SC 450 g/hm^(2)对赤霉病病指防效和DON防效分别为92.86%和89.49%,2次药后21 d对白粉病病指防效为85.84%,均高于常规药剂多菌灵和戊唑醇,并且对小麦生长安全。37%苯醚菌酯∙戊唑醇SC对赤霉病和籽粒DON毒素防效优良,同时对白粉病兼治效果良好,可开发为赤霉病防治药剂。

6%戊唑醇悬浮种衣剂包衣对小麦条锈病的防治效果

旨在明确6%戊唑醇悬浮种衣剂包衣处理对小麦条锈病的防治效果,为小麦条锈病的防控提供参考.以小麦品种'铭贤169'为试验材料,15%三唑酮可湿性粉剂作为对照药剂,采用播前种子包衣法,测定6%戊唑醇悬浮种衣剂对小麦条锈病的防治效果.结果表明,供试药剂6%戊唑醇悬浮种衣剂对小麦出苗安全,对苗期小麦条锈病有较好的防效,6%戊唑醇悬浮种衣剂处理的防效均显著高于15%三唑酮可湿性粉剂(P<0.05),达到88.35%以上.因此,6%戊唑醇悬浮种衣剂可在生产上作为小麦防治药剂进行推广应用.

吡唑醚菌酯和戊唑醇在桃中的残留与膳食风险评估

为评估桃中吡唑醚菌酯和戊唑醇残留的膳食风险,开展了8个典型地域的规范残留试验,研究了收获期2种农药残留物在桃中的最终残留。利用高效液相色谱-三重四极杆串联质谱仪(HPLC-MS/MS),通过改进,建立了吡唑醚菌酯和戊唑醇在桃中残留的分析方法。结果表明:在0.01~4.0 mg/L质量浓度范围内,吡唑醚菌酯和戊唑醇的进样浓度与峰面积之间具有良好线性关系(R^(2)≥0.9906)。添加水平为0.01~4.0 mg/kg时,桃中吡唑醚菌酯的回收率范围为88%~92%,相对标准偏差(RSD)为5.6%~18.7%,戊唑醇的回收率范围为96%~106%,RSD为0.8%~13.2%。吡唑醚菌酯和戊唑醇在桃全果中的半衰期分别为7.9~13.9 d和5.4~8.9 d;在桃全果中的残留中值(STMR)分别为0.037和0.053 mg/kg,最高残留值(HR)分别为0.16和0.24 mg/kg。距末次施药后28 d,桃中吡唑醚菌酯和戊唑醇残留量对风险商(RQ)的贡献率(RQc)分别为0.02%和0.03%,说明通过桃摄入的吡唑醚菌酯和戊唑醇对我国一般人群产生的长期膳食暴露风险较低。对于短期膳食暴露风险,吡唑醚菌酯和戊唑醇的国家估算短期摄入量(NESTI)分别占急性参考剂量(ARfD)的0.4%和2%,对于1~6岁儿童分别占2%和4%,短期膳食暴露风险亦处于可接受水平。基于本次规范残留试验结果,总体上可认为,严格按照良好农业操作规范和标签推荐的方式施用,吡唑醚菌酯和戊唑醇在桃树上使用的长期和短期膳食暴露风险均是可接受的。