《植物病蟲害綠色防控技術》課件-二、小麥白粉病綠色防控（雙語版）

二小麥白粉病綠色防控

GreenPreventionandControlofWheatPowderyMildew

二

小麥白粉病綠色防控II.GreenPreventionandControlofWheatPowderyMildew

小麥白粉病是一種世界性病害，在各主要麥區(qū)均有發(fā)生，我國山東沿海、四川、重慶、貴州、云南發(fā)生普遍且嚴重。近年來該病在東北、華北、西北麥區(qū)亦有日趨嚴重之勢。該病發(fā)生嚴重時減產(chǎn)達20%～30%，亦然成為影響小麥豐產(chǎn)的一個重要病害。

Wheatpowderymildewisaworldwidedisease,whichoccursinallmajorwheatregions.ItiscommonandseriousinShandongcoastalareas,Sichuan,Chongqing,GuizhouandYunnan.Inrecentyears,ithasbecomemoreandmoreseriousinnortheast,NorthChinaandnorthwestwheatregions.Inseverecases,itmayreduceyieldsby20%-30%,andhasbecomeanimportantdiseaseaffectingthehighyieldofwheat.（一）癥狀識別

SymptomIdentification

此病可侵害小麥植株地上部各器官，但以葉片和葉鞘為主，發(fā)病重時穎殼和芒也可受害。初發(fā)病時，葉面上出現(xiàn)1～2mm的白色霉點，后逐漸擴大為近圓形或橢圓形白色霉斑，霉斑表面有一層白粉即為該菌的菌絲體和分生孢子；后期病部霉層變?yōu)榛野咨翜\褐色，上面散生有針頭大小的小黑粒點（閉囊殼）。通常植株下部葉片較上部葉片多，葉片背面較正面多，且病斑多時常愈合成片，病葉變褐枯死，嚴重影響小麥產(chǎn)量。

Thediseasemayaffecttheabove-groundorgansofwheatplants,butmainlyleavesandleafsheaths.Glumesandawnsmayalsobeaffectedwhenitissevere.Attheinitialonset,1-2mmwhitemildewspotsappearontheleaves,andthengraduallyexpandedintoroundorovalwhitemildewspots,onthesurfaceofwhichthereisalayerofwhitepowderthatisthemyceliaandconidiaofthisfungus;andatthefinalonset,thislayeratthediseasedpartsbecomesgrayishwhitetolightbrown,withsmallblackparticles(cleistothecia)aboutthesizeofapinheadscatteredonit.Generally,therearemoreleavesinthelowerpartofaplantthanintheupperpart,moreonthebackoftheleavesthanonthefront.Manyspotsoftengatherintoalargeone,andtheaffectedleavesturnbrownandwither,whichseriouslyaffectsthewheatyield.二

小麥白粉病綠色防控II.GreenPreventionandControlofWheatPowderyMildew小麥白粉病葉片受害癥狀SymptomsofWheatPowderyMildewonLeaves小麥白粉病莖稈受害情況DamageofWheatPowderyMildewtoStems二

小麥白粉病綠色防控II.GreenPreventionandControlofWheatPowderyMildew穗部受害癥狀SymptomsofDamagetoEars后期受害癥狀SymptomsofDamageatFinalOnset二

小麥白粉病綠色防控II.GreenPreventionandControlofWheatPowderyMildew（二）病原Etiology

病菌有性態(tài)為禾布氏白粉菌，屬子囊菌亞門布氏白粉菌屬；無性態(tài)為串珠狀粉孢菌，屬半知菌亞門粉孢屬。

TheteleomorphpathogenicbacteriaareBlumeriagraminis,fallingintoBlumeriaspp.Ascomycotina,andthoseanamorphonesareOidiummonilioides,fallingintoOidiumspp.Deuteromycotina.

該病菌為表面寄生菌，在寄主植物體上表生，無色，僅以吸器伸入寄主的細胞內吸收營養(yǎng)。菌絲向上垂直生成分生孢子梗，基部膨大成球形，梗上生有成串的分生孢子，一般有6～7個至10多個。分生孢子單胞、無色、卵圓形，分生孢子壽命較短，其侵染力只能保持3～4d。病斑霉層內的黑色小顆粒為病菌的閉囊殼。閉囊殼為黑色、球形，外有發(fā)育不全的絲狀附屬絲，內含有9～30個子囊。子囊為長橢圓形，內含8個或4個子囊孢子。子囊孢子橢圓形、無色、單胞。

Thispathogenissurfaceparasiticbacteria,whichgrowonthehostplantandarecolorless,andonlyusehaustoriatoabsorbnutrientsfromthehostcells.Thehyphaeverticallygenerateconidiophoresupward,andthebaseexpandsintoaball.Thereareconidiaontheconidiophores,generally6-7tomorethan10.Conidiaareunicellular,colorless,ovoid,withshortlifespan,andtheirinfectivitycanonlybemaintainedfor3-4d.Thesmallblackparticlesinthefungallayerarethecleistotheciaofthepathogen.Thecleistotheciaareblackandspherical,withhypoplasticfiliformaccessoryfilamentsoutsideand9-30asciinside.Eachascusisoblong,containing8or4ascospores.Theascosporesareoval,colorlessandunicellular.二

小麥白粉病綠色防控II.GreenPreventionandControlofWheatPowderyMildew小麥白粉病病菌(WheatPowderyMildewPathogen)1分生孢子梗

(Conidiophore)

2分生孢子(

Conidia)

3

閉囊殼和子囊(CleistotheciumandAsci)二

小麥白粉病綠色防控II.GreenPreventionandControlofWheatPowderyMildew（三）發(fā)病規(guī)律

病菌靠分生孢子或子囊孢子借氣流傳播到感病小麥葉片上，病菌萌發(fā)開始初侵染。病菌以分生孢子階段在夏季氣溫較低地區(qū)的自生麥苗或以混雜在小麥種子內或病殘體上的閉囊殼在低溫干燥的條件下越夏。Thepathogenspreadstotheleavesofsusceptiblewheatintheformofconidiaorascosporesbymeansofaircurrents,thengerminateandstarttoinfect.Attheconidialstage,theyoversummeronthevolunteerwheatseedlingsgrowingintheareaswithlowsummertemperature,orascleistotheciablendedinwheatseedsoronplantresiduesunderlowtemperatureanddryconditions.

病菌越夏后，先侵染越夏區(qū)秋苗，發(fā)病后產(chǎn)生分生孢子向附近麥田傳播，分生孢子還可借助高空氣流遠距離傳播到非越夏區(qū)。以菌絲體或分生孢子在植株下部葉片或葉鞘上越冬。翌年春季病菌恢復活動，產(chǎn)生大量分生孢子，隨氣流傳播進行多次再侵染。

Afteroversummering,theyfirstinfectautumnseedlingsintheoverwinteringarea,andthengenerateconidia,spreadingtothenearbywheatfields.Theconidiamayalsospreadtoanon-overwinteringareabymeansofupper-airwind.Theyoverwinterintheformofmyceliaorconidiaonleavesorleafsheathsatthelowerpartoftheplant.Inthenextspring,theyresumetheiractivity,generatealargenumberofconidia,andspreadwiththeaircurrentsformultiplereinfections.二

小麥白粉病綠色防控II.GreenPreventionandControlofWheatPowderyMildew

該病在15～20℃，相對濕度大于70%的條件下發(fā)病重，但濕度過大、降雨過多則不利于分生孢子的形成和傳播。早播、密植、氮肥施用過多或地勢低洼、排水不良等因素加重該病發(fā)生。缺水、過分干旱，小麥抗病性降低，發(fā)病也重。

Thediseaseissevereat15-20℃andrelativehumidityhigherthan70%.However,excessivehumidityandrainfallarenotconducivetotheformationandspreadingofconidia.Factors,suchasearlysowing,denseplanting,excessiveapplicationofnitrogenfertilizerorlow-lyingterrainandpoordrainage,aggravatetheoccurrenceofthisdisease.Watershortage,excessivedroughtandreduceddisease-resistanceofwheatalsomakethediseasemoreserious.小麥白粉病后期病斑WheatPowderyMildewSpotsatFinalOnset二

小麥白粉病綠色防控II.GreenPreventionandControlofWheatPowderyMildew（四）防治技術

ControlTechnique

1、種植抗、耐病品種，如川麥25、綿陽26；清除自生苗，減少越夏菌源；適量增施磷鉀肥，不偏施氮肥，提高植株抗病能力；雨季及時排水，降低田間濕度；北方麥區(qū)適時澆水，使植株增強抗病力。

1.Plantdisease-resistantanddisease-tolerantcultivars,suchasChuanmai25andMianyang26;removevolunteerseedlingstoreducethesourceofoversummeringbacteria;increasephosphorusandpotassiumfertilizerappropriately,andapplynitrogenfertilizerwithoutbias,inordertoimprovethedisease-resistanceofplants;timelydrainageinrainyseasontoreducefieldhumidity;andwaterthewheatregionsinthenorthattherighttimetoenhancethedisease-resistance