【作者】 王丽；

【导师】 向文胜；

【作者基本信息】 东北农业大学 ， 农药学， 2008， 硕士

【摘要】 唑菌酯是我国具有自主知识产权的新型甲氧基丙烯酸酯类化合物,此类杀菌剂杀菌活性高、抗病谱广且与环境相容性好,作用机制独特,抑制线粒体复合物Ⅲ中电子的传递,是目前研究最热的一类杀菌剂之一。本文对唑菌酯进行了比较系统的研究,通过离体、盆栽、田间等试验,测定了该化合物对不同植物病原真菌的活性;通过形态观察、能量代谢系统、呼吸耗氧、线粒体呼吸链复合物活性测定等方法初步研究了唑菌酯的作用机制。主要研究结果如下:1.采用生长速率法和孢子萌发法测定唑菌酯的离体杀菌活性,证实了唑菌酯既能抑制菌丝生长又能抑制孢子萌发。唑菌酯对黄瓜灰霉病菌(Botrytis cinerea)、菜豆菌核病菌(Sclerotinia sclerotiorum)、水稻纹枯病菌(Rhizoctonia solani)、黄瓜炭疽病菌(Colletotrichum orbiculare)、黄瓜褐斑病菌(Corynespora cassiicola)菌丝生长有明显的抑制作用,EC50为29.57、38.92、10.89、8.667、6.986 mg/L。对黄瓜灰霉病菌(B.cinerea)、黄瓜褐斑病菌(C.cassiicola)、黄瓜炭疽病菌(C.orbiculare)和黄瓜黑星病菌(Cladosporium cucumerinum)孢子萌发抑制作用的EC50值分别为15.99、38.21、6.607和4.811 mg/L。2.采用盆栽试验法测定了唑菌酯对12种植物病原真菌的活体杀菌活性,证实了唑菌酯对半知菌亚门、鞭毛菌亚门、子囊菌亚门的9种供试病原菌的抑制率大于60%。250 mg/L下对供试黄瓜灰霉病菌(B.cinerea)、黄瓜黑星病菌(C.cucumerinum)、黄瓜霜霉病菌(Pseudoperonospora cubensis)、黄瓜炭疽病菌( C.orbiculare )、黄瓜褐斑病菌(C.cassiicola)、水稻纹枯病菌(R.solani)和黄瓜白粉病菌(Sphaerotheca fuliginea)的抑制率大于75%,与对照药剂嘧菌酯的抑制率相当。其中对黄瓜褐斑病菌(C.cassiicola)和黄瓜黑星病菌(C.cucumerinum)的抑制活性较高,其EC50值分别为6.453和4.106 mg/L。对菜豆菌核病菌(Sclerotinia sclerotiorum)和黄瓜立枯病菌(R. solani)的抑制率分别为63.48%和75.00%,低于对照药剂嘧菌酯的抑制率。对黄瓜枯萎病菌(Fusarium oxysporum)、辣椒疫霉病菌(Phytophthora capsici)、番茄晚疫病菌(Phytophthora infestans)基本没有抑菌活性。3.本研究明确了唑菌酯对黄瓜白粉病具有明显的保护作用和治疗作用,保护作用EC50为13.20 mg/L,治疗作用EC50为26.60 mg/L。田间试验结果表明,在黄瓜发病后施用20%唑菌酯悬浮剂,浓度为250 mg/L时防效较好,第三次施药后7天防效达74.07%,与对照药嘧菌酯的防效相当。4.本研究明确了唑菌酯对黄瓜霜霉病具有良好的保护作用和治疗作用,保护作用EC50为12.69 mg/L,治疗作用EC50为15.17 mg/L。田间试验结果表明,在黄瓜发病后施用20%唑菌酯悬浮剂,浓度为80 mg/L时防效较好,第三次施药后7天防效达82.78%,显著优于对照药嘧菌酯的防效。5.旁路氧化抑制剂水杨肟酸(SHAM)处理对唑菌酯抑制菌丝生长和孢子萌发的活性表现出协同增效作用,表明黄瓜灰霉病菌中旁路氧化途径影响唑菌酯的作用。存在旁路氧化抑制剂时,唑菌酯抑制菌丝生长和孢子萌发的EC50值范围分别为2.949～17.02 mg/L和0.4760～4.248 mg/L;不存在旁路氧化抑制剂时,唑菌酯抑制菌丝生长和孢子萌发的EC50值范围分别为25.96～69.92 mg/L和8.640～34.07 mg/L。6.对黄瓜灰霉病菌的菌丝耗氧率的测定,证明了唑菌酯对菌丝的耗氧率有明显的抑制作用,间接证明唑菌酯是呼吸抑制剂。唑菌酯对菌丝的耗氧率的抑制作用随浓度的增加而增强,各处理天数间差异不显著,最高抑制率为65.33%。7.通过测定牛心线粒体各复合物活性的变化,证实了唑菌酯是线粒体呼吸抑制剂,主要抑制复合物Ⅲ的活性。唑菌酯能抑制呼吸链活性的EC50值为0.9845 mg/L,因此唑菌酯作用于呼吸链,是线粒体呼吸抑制剂。对复合物Ⅲ的活性抑制作用最强烈,50 mg/L时抑制率接近80%,EC50值为4.109 mg/L。对复合物Ⅰ的活性有一定的抑制,50 mg/L时抑制率接近50%,EC50值为50.92 mg/L。对复合物Ⅱ和复合物Ⅳ的活性抑制作用不明显,50 mg/L时抑制率抑制率不到5%。根据上述结果可以看出唑菌酯具有良好的杀菌活性和独特的作用机制,对试验所得数据进行科学的分析和讨论,为唑菌酯的进一步推广应用提供科学依据,为该类化合物结构优化及其在绿色杀菌剂的研制过程中的应用提供参考。更多还原

【Abstract】 Pyraoxystrobin was a product of the strobilurin compounds synthetized in China,the Strobilurin fungicides was a new fungicide with unique action mechanism,high germicidal activity,and safety in the enviroment.The fungicidal activity stems from the fact that they inhibit mitochondrial respiration in fungi by at a specific site on complexIlI.The control effects of pyraoxystrobin on plant pathogenic fungus were tested in lab,greenhouse and field.we studied the primary antifungal action mechanism of pyraoxystrobin with the techniques of morphology,oxygen consumption,activities of respiratory chain and so on.And the main study results were as follows:1.The activity in vitro studies disclosed that pyraoxystrobin inhibited mycelia growth and conidia germination.Mycelia growth of Botrytis cinerea,Sclerotinia sclerotiorum,Rhizoctonia solani,Corynespora cassiicola,Colletotrichum orbiculare was sensitive to pyraoxystrobin,and EC50 values were 29.57,38.92,10.89,8.667,6.986 mg/L.Conidia germination of B.cinerea, C. cassiicola, C.orbiculare and Cladosporium cucumerinum was sensitive to pyraoxystrobin,and EC50 values were 15.99,38.21,6.607 and 4.811 mg/L.2.The activity in vivo studies disclosed that the control effect of pyraoxystrobin to 9 species of phytopathogenic fungi of Deuteromycotina,Ascomycotina,Mastigomycotina was more then 60%. The control effects of 250 mg/L was more then 75% and similar to azoxystrobin on most plant pathogenic fungi such as B.cinerea,C.cucumerinum,C.cassiicola,Sphaerotheca fuliginea, Pseudoperonospora cubensis,C.orbiculare and R.solani.The control activity of pyraoxystrobin to C.cucumerinum and C.cassiicola was higher and EC50 values were 4.106 and 6.453mg/L.But almost no activity to Phytophthora capsici,Fusarium oxysporum and Phytophthora infestans.3.This research was found out that the pyraoxystrobin expressed an excellent protection and control activity to cucumber powdery mildew.The EC50 values of protection and control activity were 13.20 mg/L and 26.60 mg/L,and the control effects of 250 mg/L were 79.65% and 77.54%. The field trial showed that application of pyraoxystrobin 20% SC after infection could effective control powdery mildew,7 days after the 3rd round of application,the control efficacy of 250 mg/L was 74.07%,and similar to azoxystrobin.4.The result disclosed that the pyraoxystrobin expressed an excellent protection and control activity to cucumber downy mildew.The EC50 values of protection and control activity were 12.69 mg/L and 15.17 mg/L,and the control effects of 250 mg/L were 85.31% and 83.79%. The field trials showed that application of pyraoxystrobin 20% SC after infection could effective control downy mildew,7 days after the 3rd round of application,the control efficacy of 80mg/L was 82.78%, and outstrip the effect of azoxystrobin. 5.Salicylhydroxamic acid (SHAM) is a specific inhibitor of alternative oxidase can increase the effect of pyraoxystrobin,testified alternative respiration affects the activity of pyraoxystrobin to B.cinerea.The results showed that in the presence of 50 mg/L SHAM,the EC50 value inhibited mycelia growth ranged from 2.949 to 17.02 mg/L,in the absence of SHAM,the EC50 value ranged from 25.96 to 69.92 mg/L; in the presence of 50 mg/L SHAM, the EC50 walue inhibited conidia germination ranged from 0.4760 to 4.248 mg/L,in the absence of SHAM,the EC50 ranged from 8.640 to 34.07 mg/L.Meanwhile,SHAM expressed a notable synergistic interaction with pyraoxystrobin against B. cinerea.6.Oxygen consumption test of mycelia showed that pyraoxystrobin strongly inhibited mycelial respiration,testified pyraoxystrobin was a respiration inhibitor.A streatment time went on,the respiration inhibition on the mycelia had no evident change,but the effect became stronger when the concentration was increased.The highest inhibition ratio was 65.33%.7.By determining the compound activity variation of beef heart mitochondria,confirmed pyraoxystrobin was a potent inhibitor of mitochondrial electron transport,mainly inhibited the activity of complex III.Inhibitted mitochondrial electron transport the EC50 value was 0.9845 mg/L.The inhibitor mainly inhibited the activity of complex III,the EC50 value was 4.109 mg/L, the control effect of 50 mg/L was nearly 80%.It was a weak inhibitor of complex I,and EC50 value was 50.92 mg/L,the control effect of 50 mg/L was nearly 50%. Pyraoxystrobin can not inhibit the activity of complex II and complex IV in beef heart mitochondria, the control effects of 50 mg/L was lower than 5%.According to result described above pyraoxystrobin has good germicidal activity and unique action mechanism.Carry on scientific analysis and discuss in testing the result data can supply reference for the structural optimization of strobilurin derivatives and application during the development of the green fungicide.更多还原