Bt作物的昆蟲(chóng)抗藥性管理

Bt作物的昆蟲(chóng)抗藥性管理2024/3/13Bt作物的昆蟲(chóng)抗藥性管理IRM:whatisit?

昆蟲(chóng)抗藥性管理定義 Insectresistancemanagement(IRM)isastrategytomitigatethedevelopmentofinsectsresistanttoapesticide(e.g.,resistancetoBacillusthuringiensisorBt)昆蟲(chóng)抗藥性管理(IRM)是為了減輕害蟲(chóng)對(duì)殺蟲(chóng)劑(例如對(duì)BT)產(chǎn)生抗性而采取的一種策略.2Bt作物的昆蟲(chóng)抗藥性管理IRM:whyisitimportant?

IRM的重要性MaintainingtheefficacyofBt,alow-riskpesticide,isbeneficialforthefollowingreasons:維持低風(fēng)險(xiǎn)殺蟲(chóng)劑Bt的功效有如下的優(yōu)點(diǎn):BtreplaceshigherriskpesticidesBt殺蟲(chóng)劑可以代替其他高風(fēng)險(xiǎn)性的殺蟲(chóng)劑Lessexposureofnontargetorganismstosuperficiallyappliedpesticides降低非目標(biāo)生物暴露于殺蟲(chóng)劑的可能性UseofBtcropsmayprovidegreaterprofitstofarmers,duetoreduceduseofinsecticides由于減少了殺蟲(chóng)劑的使用,Bt作物可以給農(nóng)民帶來(lái)更大的收益3Bt作物的昆蟲(chóng)抗藥性管理CriticalcomponentsofIRMplan

IRM計(jì)劃的重要組成成分Pestbiology害蟲(chóng)生物學(xué)Dose劑量Cross-resistance抗性轉(zhuǎn)移Refuge避難所Modeling建立模型Resistancemonitoring抗性監(jiān)測(cè)Remedialaction矯正措施Complianceassurance確保規(guī)范性Growereducation種植者教育4Bt作物的昆蟲(chóng)抗藥性管理Pestbiology

害蟲(chóng)生物學(xué)Importantfactorsinclude:NumberofinsectgenerationsperyearHostrangeInsectmovementanddispersalpatternsMatingandovipositionalbehaviorPopulationdynamics要點(diǎn)包括:每年害蟲(chóng)繁殖的代數(shù)宿主的范圍害蟲(chóng)移動(dòng)和分布的模式交配和產(chǎn)卵行為種群動(dòng)態(tài)5Bt作物的昆蟲(chóng)抗藥性管理Pestbiology:anexample

害蟲(chóng)生物學(xué)舉例Europeancornborer(ECB),Ostrinianubilalis1-4generationsperyearPolyphagous(preferscorn)Movement:Larvae-canmovefromplant-to-plantwithinafieldAdults-mostlylocalmovement,butsomelongdistancemigratorymovementcanoccur歐洲玉米螟(ECB)每年繁殖1-4代雜食性(偏好玉米)移動(dòng)幼蟲(chóng)可以在同一田地內(nèi)不同植株上移動(dòng)成蟲(chóng)大部分在本地活動(dòng),但也有可能進(jìn)行長(zhǎng)距離遷移Female雌性Male雄性lateinstars晚期幼蟲(chóng)ECB6Bt作物的昆蟲(chóng)抗藥性管理Dose劑量Dose=theamountoftoxinexpressedovertimebyatransgeniccrop,relativetothesusceptibilityofatargetpest;canbedeterminedthroughfieldefficacytrialsorlaboratorybioassays劑量=轉(zhuǎn)基因作物在一定時(shí)間內(nèi)表達(dá)的毒素的量,和目標(biāo)害蟲(chóng)的敏感性相關(guān);通常由田間功效實(shí)驗(yàn)或?qū)嶒?yàn)室生物測(cè)試所決定.Highdose=atleast25xtheamountoftoxinneededtokillallsusceptibletargetinsects;preferredoverlowdoseeventsforrefuge-basedIRMstrategies高劑量=至少為殺死所有敏感目標(biāo)害蟲(chóng)劑量的25倍;在以避難所為基礎(chǔ)的昆蟲(chóng)抗性管理策略中，使用高劑量遺傳事件體要比低劑量遺傳事件體好7Bt作物的昆蟲(chóng)抗藥性管理Doseassumptions

劑量假設(shè)Threegenotypesforresistance/susceptibility(SS,rS,rr)Resistance(rr)isrecessiveandrareRefugesuppliesSS(homozygoussusceptible)genotypeRandommating:rrxSS→rSrSxSS→rSorSSSSandrSsusceptibletohighdose三種抗性/敏感性基因型(SS,rS,rr)抗性基因(rr)是隱性的,少見(jiàn)的安全基因型SS(純合敏感)隨機(jī)交配:rrxSS→rSrSxSS→rSorSSSS和rS對(duì)高劑量敏感LC500100低高8Bt作物的昆蟲(chóng)抗藥性管理Doselevels:someexamples

關(guān)于劑量水平的一些例子Lepidopteran-activecorn(Cry1Ab&Cry1F):HighdoseEuropeancornborer(ECB),OstrinianubilalisSouthwesterncornborer(SWCB)DiatraeacrambidoidesNon-highdoseCornearworm(CEW),Helicoverpazea鱗翅目敏感玉米(Cry1Ab&Cry1F):高劑量歐洲玉米螟(ECB),Ostrinianubilalis西南玉米螟(SWCB)Diatraeacrambidoides非高劑量玉米棉鈴蟲(chóng)(CEW),HelicoverpazeaWCRfemalemalelateinstarsECB9Bt作物的昆蟲(chóng)抗藥性管理Doselevels:someexamples

關(guān)于劑量水平的一些例子Rootworm-activecorn(Cry3Bb1,Cry34/35,mCry3A)Non-highdoseWesterncornrootworm(WCR),DiabroticavirgiferavirgiferaNortherncornrootworm(NCR),D.barberiMexicancornrootworm(MCR),D.virgiferazeaSecondarypestsNon-highdoseforsomepests根蟲(chóng)敏感玉米(Cry3Bb1,Cry34/35,mCry3A)非高劑量西部玉米根蟲(chóng)(WCR),Diabroticavirgiferavirgifera北部玉米根蟲(chóng)(NCR),D.barberi墨西哥玉米根蟲(chóng)(MCR),D.virgiferazea次級(jí)害蟲(chóng)非高劑量WCRfemalemalelateinstarsECB10Bt作物的昆蟲(chóng)抗藥性管理Cross-resistance

抗性轉(zhuǎn)移WhenresistancetoasingleBttoxinconferspestresistancetoaclusterofrelatedtoxinsFactorsaffectingcross-resistanceinclude:Similarity/dissimilarityofcommercializedtoxinsUseofsingletoxinversusmultipletoxinsLevelofresistanceinaninsectpopulation害蟲(chóng)對(duì)單一Bt蛋白的抗性使得害蟲(chóng)對(duì)其他一系列相關(guān)毒素都產(chǎn)生抗性影響抗性轉(zhuǎn)移的因素包括:商品用毒素的異同點(diǎn)單一毒素和復(fù)合毒素的使用昆蟲(chóng)種群的抗性水平11Bt作物的昆蟲(chóng)抗藥性管理Cross-resistance:anexample(抗性轉(zhuǎn)移:舉例說(shuō)明)BindingsitediagramforEuropeancornborer(歐洲玉米螟結(jié)合位點(diǎn)簡(jiǎn)圖)Cry1AbCry1FCry1Ac220KDaCadherin154KDaAPN145/167KDaAPNOtherEuropeancornborer(basedonHua,G.,Masson,L.,Jurat-Fuentes,J.L.,Schwab,G.,Adang,M.J.2001.BindinganalysesofBacillusthuringiensisCryd-endotoxinsusingbrushbordermembranevesiclesofOstrinianubilalis.Appl.Env.Microbiol.67:872-879)(其他)12Bt作物的昆蟲(chóng)抗藥性管理Refuge避難所AnyhostplantthatdoesnotproduceBttoxinandhasnotbeentreatedwithconventionalBtformulations(maybetreatedwithnon-Btinsecticide)任何不產(chǎn)生Bt毒素并且也未經(jīng)常規(guī)Bt殺蟲(chóng)劑處理過(guò)的宿主植物(可能經(jīng)非Bt殺蟲(chóng)劑處理過(guò))Enablesmatingbetweenresistantandsusceptibleadults,resultinginproductionofsusceptibleoffspring抗性和敏感性成熟植株雜交可以產(chǎn)生敏感性的后代13Bt作物的昆蟲(chóng)抗藥性管理Refugeoptions 避難所的選擇Structuredrefuge=specifiedsize,locationinrelationtoBtfield,andcrop/plantcompositionCommunity-basedrefuge=neighboringgrowersestablishsharedstructuredrefugeUnstructuredornaturalrefuge=useofalternativehostplants/cropsinplaceofdefinedrefuge結(jié)構(gòu)避難所=特定大小,并且位置和Bt植物種植區(qū)有一定關(guān)系的區(qū)域,此區(qū)域既有農(nóng)作物,又有植被以社區(qū)為基礎(chǔ)的避難所=相鄰的種植者建立的一種共享的結(jié)構(gòu)避難所非結(jié)構(gòu)或稱(chēng)天然避難所=用一種寄主植物和作物互相交替種植的模式來(lái)代替人為限定的避難所模式14Bt作物的昆蟲(chóng)抗藥性管理Refugeoptions 避難所的選擇Seedbagmix=BtseedbagscontainBtseedandnon-Btseed(e.g.,80%Bt,20%non-Bt);seedmaybebaggedseparatelyormixedtogetherRegionallimit=national/regionalgovernmentenforcedlimitonBtseedsales(e.g.,80%indefinedregion)混裝種袋=在這種含Bt種子的袋子中既含有Bt種子,也含有非Bt種子(例如:80%Bt種子,20%非Bt種子),種子可以先按小袋分裝好再混和,也可以直接混在一起.區(qū)域限制=國(guó)家或地方政府對(duì)Bt種子的買(mǎi)賣(mài)進(jìn)行嚴(yán)格限制(例如:在一定區(qū)域內(nèi)，只允許80%的Bt種子的買(mǎi)賣(mài))15Bt作物的昆蟲(chóng)抗藥性管理SeedmixBlockIn-fieldstrips田地內(nèi)的條帶模式Internalblock(s)內(nèi)部種植模式Border(block)周邊種植模式Structuredrefugeoptions

結(jié)構(gòu)避難所的選擇Externalblock外部種植模式種子混和16Bt作物的昆蟲(chóng)抗藥性管理Otherrefugeoptions

其他避難所選擇Communityrefuge社區(qū)避難所模式80%Bt

seedcorn玉米種子20%non-Bt

seedcorn玉米種子Naturalrefuge天然避難所BtcottonBt棉花w/TBWSoybean大豆Tobacco煙草Tobaccobudworm,煙草蚜蟲(chóng)Heliothisvirescens

17Bt作物的昆蟲(chóng)抗藥性管理Btcornrefugespecifications:anexample

Bt玉米避難所規(guī)范示例20%refugerequiredincornbelt;50%refugerequiredincorn/cottonregionStructuredrefugeisrequired.Refugesmaybeplantedinoneofthefollowingdesigns:In-fieldstrips(4-6rows)Blocks(internalorexternal)Refugerequirementsarethesameforlepidopteranandcoleopteranactiveproducts在Bt玉米田中20%為避難所,在玉米/棉花田中則為50%結(jié)構(gòu)性避難所是必須的.避難所可以按如下的設(shè)計(jì)來(lái)耕作:田地內(nèi)條帶(4-6行)內(nèi)部或外部田塊18Bt作物的昆蟲(chóng)抗藥性管理Modeling模擬Usefultoolforpredictingthelikelihoodofresistance,forevaluatingthedurabilityofIRMstrategies,andforhelpingtofocusdataneeds.Modelcomponentsinclude:Biologicalinformation(pestbiology,populationdynamics)Genetics(R-alleledominance/frequency,crossresistance)Operationalaspects(dose,single/stackedtoxin(s),refuge)建立模型是預(yù)測(cè)抗藥可能性,評(píng)價(jià)IRM策略持久性和幫助調(diào)整數(shù)據(jù)需求的一種有效方法.模型包括以下組成成分:生物信息(害蟲(chóng)生物學(xué),種群動(dòng)態(tài))遺傳學(xué)(R-等位基因顯性/頻率,抗性轉(zhuǎn)移)運(yùn)行情況(劑量,單一的/疊加的毒劑,避難所)19Bt作物的昆蟲(chóng)抗藥性管理Resistancemonitoring

抗性監(jiān)測(cè)CanhelptoprolongtheefficacyofaninsectresistantcropDesignedtodetectresistance2-3yearsbeforefieldfailureTargetpestsamplingconsistsof:Growerreportsofunexpectedpestdamageininsect-protectedcropfieldsRandompopulationsampling:SamplingbasedonpestprevalenceinregionSamplingtarget:numberofinsectsneededtodetermineresistanceatp<0.01

可以延長(zhǎng)抗蟲(chóng)作物的功效可以在失效前監(jiān)測(cè)抗性2-3年目標(biāo)害蟲(chóng)取樣包括:種植者在抗蟲(chóng)作物區(qū)域內(nèi)由害蟲(chóng)造成的意外損失報(bào)告隨機(jī)種群取樣:害蟲(chóng)流行區(qū)域取樣取樣目標(biāo):用來(lái)確定抗性所需的害蟲(chóng)數(shù)量(p<0.01)20Bt作物的昆蟲(chóng)抗藥性管理Resistancemonitoring(cont.)

抗性監(jiān)測(cè)(續(xù))Bioassaysareusedtodetectpotentialresistanceinsampledpopulations.Assaysinclude:Pestsusceptibility(LC50)DiscriminatingDose(LC99)F2screenConfirmationstudiesareusedtoverifyresistance.Questionsinclude:Istherefieldfailure?Istheinsectresistancetraitexpressed?Isinsectresistancetraitinherited?用生物鑒定來(lái)檢測(cè)樣品種群中的潛在抗性.生物鑒定包括:害蟲(chóng)敏感性鑒定(LC50)差異劑量(LC99)F2篩選確認(rèn)研究用來(lái)核實(shí)抗性.包括:區(qū)域失效了么?抗性特征表達(dá)了么?抗性性可遺傳么?21Bt作物的昆蟲(chóng)抗藥性管理Resistancemonitoring:positivehitsforBtcornintheUS?抗性監(jiān)測(cè):美國(guó)Bt玉米正采樣數(shù)In2001,mortalityforoneEuropeancornborer(ECB)population(Kandiyohi,MN)was<99%inCry1AbdiscriminatingdoseassayFollow-uptestswithBtplantmaterialrevealedthatpopulationwasnotfieldresistantNofieldresistanceconfirmedforanymonitoredBtcornpest2001年在Cry1Ab不同劑量分析中,歐洲玉米螟種群的死亡率小于99%Bt作物的后續(xù)測(cè)試表明種群并沒(méi)有田間抗藥性被監(jiān)測(cè)的Bt玉米害蟲(chóng)沒(méi)有被證實(shí)產(chǎn)生田間抗藥性22Bt作物的昆蟲(chóng)抗藥性管理Remedialactionplan

矯正措施 Ifresistanceisconfirmedthroughresistancemonitoring,aremedialactionplanisimplementedtocontainorslowthespreadofresistantpestpopulations

如果抗性監(jiān)測(cè)確認(rèn)了抗藥性,矯正措施可以減緩害蟲(chóng)種群抗藥性的傳播23Bt作物的昆蟲(chóng)抗藥性管理Remedialactionplan:anexample

矯正措施舉例EPA’splanincludes:MandatoryreportingofsuspectedresistanceUseofalternatecontrolmeasuresinaffectedareasIncreasedresistancemonitoringSuspensionofBtcropsalesinaffectedareasInvestigationofcauseofresistance美國(guó)環(huán)保局措施包括:強(qiáng)制要求對(duì)有懷疑的抗藥性表現(xiàn)上報(bào)在有影響區(qū)域使用其他管理措施增強(qiáng)抗性監(jiān)測(cè)在被影響區(qū)域終止Bt玉米銷(xiāo)售對(duì)抗藥性原因進(jìn)行調(diào)查24Bt作物的昆蟲(chóng)抗藥性管理Complianceassurance

確保規(guī)范性

CompliancemeasuresimplementedtoensurethatgrowerscomplywithapprovedIRMprogram規(guī)范操作可以確保種植者按照害蟲(chóng)抗藥性管理規(guī)則執(zhí)行耕種操作.25Bt作物的昆蟲(chóng)抗藥性管理Complianceassurance:anexample

確保規(guī)范性舉例EPArequiresregistrantstoimplementthefollowingmeasures:ContractsaffirminggroweragreementtocomplywithapprovedIRMstrategy3rdpartygrowersurveysofIRMimplementationOn-farmfieldvisitstoverifyIRMimplementationTipsandcomplaintsonnon-compliersSuspensionofseedaccessfornon-compliers美國(guó)環(huán)保局規(guī)定登記者必須實(shí)施以下方法:合同規(guī)定種植者必須遵守IRM策略第三方對(duì)IRM執(zhí)行情況進(jìn)行調(diào)查田間觀(guān)察以確定IRM的執(zhí)行情況揭發(fā)和投訴不遵守規(guī)則的種植者對(duì)不遵守規(guī)則的種植者終止種子供應(yīng)26Bt作物的昆蟲(chóng)抗藥性管理Growereducation

種植者教育

EducationabouttheneedforIRM,howtoimplementrequirements,andgrowerresponsibilityincomplyingwithIRMrequirements對(duì)IRM策略的必要性,怎樣完成要求,和種植者對(duì)完成IRM要求所擔(dān)負(fù)的責(zé)任進(jìn)行教育27Bt作物的昆蟲(chóng)抗藥性管理SummaryofEPA’sIRMrequirementsforlepidopteran-activeBtcorn

美國(guó)環(huán)保局對(duì)鱗翅目昆蟲(chóng)敏感的Bt玉米IRM要求概述20%refugeincornbelt;50%refugeincottonbeltStructuredrefugerequired.Refugesplantedinoneofthefollowingdesigns:in-fieldstrips(4-6rows)blocks(internalorexternal)Industry-widecollaborationoncompliancesurveys在玉米種植帶中20%為避難所;在棉花種植帶中為50%結(jié)構(gòu)性避難所是必需的.避難所種植需為如下設(shè)計(jì)中的一種:田間條帶(4-6行)田塊(內(nèi)部或外部)廣泛合作開(kāi)展規(guī)范性調(diào)查28Bt作物的昆蟲(chóng)抗藥性管理SummaryofEPA’sIRMrequirementsforlepidopteran-activeBtcorn(cont.)

對(duì)鱗翅目昆蟲(chóng)敏感的Bt玉米IRM要求概述(續(xù))Industry-wideuniformityof:GroweragreementsGrowertrainingImplementationoftipsandcomplaints以下行為保持高度一致性:種植者協(xié)議種植者培訓(xùn)監(jiān)測(cè)和投訴的實(shí)施29Bt作物的昆蟲(chóng)抗藥性管理SummaryofEPA’sIRMrequirementsforlepidopteran-activeBtcorn(cont.)對(duì)鱗翅目昆蟲(chóng)敏感的Bt玉米IRM要求概述(續(xù))Annualreportingrequirements:－Complianceassurance(e.g.,surveys,growercontracts)－Changestogrowereducation－Resistancemonitoringdata－Salesdata年度報(bào)告需要:規(guī)范性確認(rèn)材料(例如調(diào)查,種植者合同)種植者教育的變化抗性監(jiān)測(cè)數(shù)據(jù)銷(xiāo)售數(shù)據(jù)30Bt作物的昆蟲(chóng)抗藥性管理DatasourcesforEPA’sIRMprogram

美國(guó)環(huán)保局IRM項(xiàng)目的數(shù)據(jù)來(lái)源PublishedscientificliteratureIndustrysubmissionsExperts(academia,government,industry)Meetings(advisorypanels,workshops,ESA,NC205,NC46)Fieldvisits已出版的科學(xué)文獻(xiàn)工業(yè)企業(yè)的報(bào)告專(zhuān)家(學(xué)術(shù)界,政府,工業(yè)界)會(huì)議(顧問(wèn)團(tuán),研討會(huì),ESA,NC205,NC46)田間觀(guān)察31Bt作物的昆蟲(chóng)抗藥性管理KeystosuccessatEPA

美國(guó)環(huán)保局(EPA)取得成功的關(guān)鍵EPAisresponsivetonewscientificinformationEPAseeksscientificinputfromstateandfederalagencies,academicexperts,andpublicinterestgroupsEPA對(duì)最