1、RESEARCHREPORTSdoi:10.16801/j.issn.1008-7303.2022.0117Bioactivities of five fungicides against Rhizoctonia solani,the causalagent of tobacco sore shinXIANGLigang1,WANGHancheng*,2,CAILiuti2,LUNing2,CHENXingjiang2,YUZhihe3(1.College of Agriculture,Yangtze University,Jingzhou 434025,Hubei Province,Chin
2、a;2.Guizhou Academy of Tobacco Science,Guiyang 550081,China;3.College of Life Science,Yangtze University,Jingzhou 434025,Hubei Province,China)Abstract:TobaccosoreshincausedbyRhizoctonia solaniisoneofthemostdestructivediseasesintheseedbedsufferedbytobaccoinChina.Thisstudyevaluatedtheactivitiesofthefu
3、ngicidesazoxystrobin,boscalid,fluazinam,propiconazole,andpyrimethanilagainstmycelialgrowth,sclerotiaformationandgerminationof R.solani,andalsotheirprotectiveandcurativeefficaciesagainsttobaccosoreshin.ThemycelialgrowthofR.solaniwasmoresensitivetofluazinamandazoxystrobinthantopropiconazoleandboscalid
4、,andleastsensitivetopyrimethanil.Azoxystrobinshowedstrongerinhibitionofsclerotiaproductionthanpropiconazole,fluazinam,pyrimethanil,andboscalid.NoneofthefivefungicidesinhibitedthesclerotiagerminationofR.solani.Intermsoftheprotectiveactivityofdetachedtobaccoleaves,azoxystrobinandboscalidat12.5and50mg/
5、Lweresuperiortofluazinam,propiconazole,andpyrimethanilinreducingsoreshin.Forcurativeactivity,azoxystrobinat50and200mg/Lwassuperiortotheotherfourfungicidesinreducingdisease.Therefore,amongthefivefungicides,azoxystrobinismostsuitableforthecontroloftobaccosoreshin.Keywords:Rhizoctonia solani;azoxystrob
6、in;sensitivity;sclerotiumproduction;controlefficacy五种杀菌剂对烟草立枯病菌的生物活性向立刚1,汪汉成*,2,蔡刘体2,陆宁2,陈兴江2,余知和3(1.长江大学农学院，湖北荆州434025；2.贵州省烟草科学研究院，贵阳550081；3.长江大学生命科学学院，湖北荆州434025)摘 要：由立枯病丝核菌引起的烟草立枯病是我国烟草苗床上危害最严重的病害之一。本研究评价了 5 种杀菌剂(嘧菌酯、啶酰菌胺、氟啶胺、丙环唑和嘧霉胺)对立枯丝核菌菌丝生长、菌核形成和萌发的影响，以及其对烟草立枯病的防治效果。结果表明：立枯丝核菌菌丝对氟啶胺和嘧菌酯的敏感性
7、高于丙环唑和啶酰菌胺，而对嘧霉胺的敏感性较低；嘧菌酯对菌核形成的抑制作用强于丙环唑、氟啶胺、啶酰菌胺和嘧霉胺；5 种杀菌剂对立枯丝核菌菌核萌发均无抑制作用。在离体烟叶的保护活性方面，12.5 和 50mg/L 的嘧菌酯和啶酰菌胺对立枯病的保护作用优于氟啶胺、丙环唑和嘧霉胺；在治疗活性方面，50 和 200mg/L 的嘧菌酯的治疗作用优于其他 4 种杀菌剂。因此，供试的 5 种杀菌剂中嘧菌酯最适合用于烟草立枯病的防治。关键词:立枯丝核菌；嘧菌酯；敏感性；菌核形成；防治效果中图分类号：S435.11文献标志码：A Received:May 15,2022;Accepted:September5,2
8、022;Published online:October10,2022.URL:https:/doi.org/10.16801/j.issn.1008-7303.2022.0117http:/ Journal of Pesticide ScienceE-mail:Tobacco(Nicotiana tabacumL.)isaleafy,annual,solanaceousplant.ItisanimportanteconomiccropintheworldandiscommerciallygrowninChinaforitsleaves1.Chinaisthelargestsingletoba
9、ccomarketintheworld,accountingfor40%ofglobaltobaccoproductionandconsumption2.TobaccosoreshincausedbyRhizoctonia solaniKhn,isadestructivediseaseintheseedbedandfrequentlyoccursduringseedlingdevelopment3.Allofthetobaccostembases,leaves,androotsaresusceptible.Thediseaseoccursfrequentlyeachyearintwomajor
10、tobaccocommercialregions:YunnanandGuizhouprovinces.Withoutchemicalcontrol,thelossreachesmorethan50%4.Asaubiquitoussoil-bornepathogen,R.solani,infectnotonlytobaccobutalsomanyotherhostsincludingsugarbeet5,rice6,soybean7,potato8,lettuce9,etc.ThroughoutthehistoryofRhizoctoniadiseasemanagement,manysynthe
11、ticfungicideshavebeenusedtocontrolR.solani,includingvalidamycin10,hymexazol11,azoxystrobin12,boscalid13,propicona-zole14andfluazinam15.Itisimportanttounderstandthein vitroactivityofafungicideagainstapathogenatvariouslifecyclestages,especiallyforthemycelialgrowthandsclerotiumformationandgerminationof
12、R.solani.Additionally,thein vivoactivityofachemicalagainstdiseaseisalsocriticalfordiseasemanage-ment.InChina,fourfungicideswithdifferentmodesofactionhavebeenutilizedforRhizoctoniadiseasemanagementonfieldcrops,includingazoxystrobin(mitochondrialcomplexIIIQositeinhibitor),boscalid(succinatedehydrogena
13、seinhibitor),fluazinam(uncouplerofoxidativephosphorylation),andpro-piconazole(sterolbiosynthesisinhibitor).However,onlyolderregisteredfungicidessuchashymexazol16,mancozeb16,isoprothiolane,andzinebareusedfortobaccosoreshinmanagementinChina.Theabovefungicides,boscalid,fluazinam,andpropiconazolearenoty
14、etregisteredontobaccoinChina,andazoxy-strobinwasonlyregisteredontobaccolastyearasacompoundwithdifenoconazole.Lastbutnotleast,thereisnorelevantresearchonthein vitroactivitiesofthesefungicidesagainstR.solaniisolatedfromtobaccoinChina.Basedonpreviousstudies,wefoundthatthesensitivityofthespeciesfromdiff
15、erenthoststoafungicidevaries.Forexample,theEC50valuesofdifenoconazoleagainstR.solaniisolatedfromtobaccoandwheatwere(0.550.53)g/mLand(0.1650.101)g/mL,respectively16-17.TheEC50valuesofcarbendazimagainstR.solaniisolatedfromtobacco,cotton,andsesamewere0.06,0.606,and1.064g/mL,respectively16,18-19.Therefo
16、re,theobjectivesofthisstudywereto(i)evaluatetheinvitroactivitiesofthefungicidesazoxystrobin,boscalid,fluazinam,andpropiconazoleduringdifferentlifestages(mycelialgrowth,sclerotiumformation,andsclerotiumgermination)ofR.solani;(ii)assessthein vivoactivitiesofthosechemicalsagainsttobaccosoreshin.Thefungicidepyrimethanil,whichisnormallysprayedontheseedbedtocontroltobaccograymold,wasselectedasacontrol.ThisstudywouldprovideusefulinformationforthemanagementoftobaccosoreshininChina.1 Materials and method
