玫烟色棒束孢的生物学特性与其对小菜蛾致病力的相关性

雷妍圆1吕利华2何余容1*梁淑仪1(1.,510642;2.,510640):测定了玫烟色棒束孢原始亲本菌株PFCFO退化亲本菌株PFCFD和单孢分离子菌株PFCFD58PFCFD20PFCFD50的菌落生长速率产孢量孢子萌发率和胞外蛋白酶水平等生物学指标以及各菌株对小菜蛾2龄幼虫的校正死亡率结果表明,菌株PFCFO的生长速率呈先快后慢的趋势,产孢量为2.7107个/mL,孢子萌发率为62.59%,胞外蛋白酶水平为1.16,对小菜蛾2龄幼虫校正死亡率达97.74%而菌株PFCFDPFCFD20PFCFD50和PFCFD58间平均生长速率和孢子萌发率无显著差异,产孢量变化范围为1.05107~2.34107个/mL,胞外蛋白酶水平变化范围为1.02~1.07,各生物学指标及其对小菜蛾2龄幼虫的校正死亡率(19.86%~51.44%)都显著低于菌株PFCFO相关性分析结果显示,玫烟色棒束孢对小菜蛾的致病力与菌株生长初期的生长速率产孢量孢子萌发率和胞外蛋白酶水平呈极显著的正相关关系,与菌株生长后期的生长速率呈极显著负相关关系:玫烟色棒束孢;小菜蛾;生物学特性;致病力;相关性CorrelationbetweenbiologicalcharacteristicsofIsariafumosoroseaanditspathogenicityagainstPlutellaxylostellaLeiYanyuan1LLihua2HeYurong1*LiangShuyi1(1.CollegeofResourcesandEnvironment,SouthChinaAgriculturalUniversity,Guangzhou510642,GuangdongProvince,China;2.PlantProtectionResearchInstitute,GuangdongAcademyofAgriculturalSciences,Guangzhou510640,GuangdongProvince,China)Abstract:InordertoexplicitthecorrelationbetweenbiologicalcharacteristicandpathogenicityofIsariafumosorosea(=Paecilomycesfumosoroseus)toPlutellaxylostella,fiveI.fumosoroseastrains,includingoriginalfatherstrainPFCFO,degeneratedfatherstrainPFCFD,singlesporeisolatesPFCFD58,PFCFD20,andPFCFD50,whichisolatedfromPFCFD,wereassayedonsporulation,growthrate,sporegerminaterate,extracellularproteaseandtheirpathogenicitytothe2ndinstarlarvaofP.xylostella.TheresultsshowedthatthegrowthrateofstrainPFCFOwasfastatinitialstageafterinoculatedtomedialbutsloweddownwiththetimeelapsed.ThestrainPFCFOappearedanobviouslyhighersporulation(2.7107conidial/mL)after20daysculture,sporegerminaterate(62.59%),extracellularproteaselevel(1.16)andcorrectedmortality(97.74%)tothe2ndinstarlarvacomparedtootherstrains.However,amongthestrainsPFCFD,PFCFD20,PFCFD50andPFCFD58,therewerenosignificantdifferencesonthegrowthrateandsporulationgerminaterate.Sporulationofthesestrainswas1.05107-2.34107conidial/mLandextracellularproteaselevelwas1.02-1.07.Thecorrectedmortalityofthesefour:(200803001),(2006B20301037):,,1981,,,emai:[e-mail]*(Authorforcorrespondence),emai:[e-mail];:2009-08-2337320106植物保护学报ACTAPHYTOPHYLACICASINICAVo.l37No.3June2010strainstothe2ndinstarlarvawas19.86%-51.44%,significantlylowerthanthatofstrainPFCFO.ThepathogenicityofI.fumosoroseaagainstP.xylostellasignificantlycorrelatedtothesporulation,sporegerminaterate,extracellularproteaselevelandstrainsgrowthrateoftheinitialstageafterinoculatedtomedia,lbutnegativelytothegrowthrateofthelaterstageafterinoculatedtothemedia.lKeywords:Isariafumosorosea;Plutellaxylostella;biologicalcharacteristic;pathogenicity;correlationPlutellaxylostellaL.,,[1],,50[2-3],,,Isariafumosorosea,,20,,,PFR97[4-5],2080[6],[7-8][9]SCAUPFCF012LT501.66,LC501.17104/mL,,,SCAUPFCF01(=PFCFO)PFCFDPFCFD58PFCFD20PFCFD50,,2,11.1PFCFOCoptotermesformosanusShiraki,1SDAY20,1,-801.2SDAY(9cm,)20,0.05%80,1.0107/mL,99mLSDY(SDAY)1mL,25110r/min(250mL)48h1mm2,25mLSDAY,,255,2,5,461.3SDAY20,13mm1/210mL-(GP)10.05%8050mL,25110r/min(250mL)13h,3,1.4[10]-15mL,,5255,r1.51.2,2,,10s,,9cm,0.05%80,,5,25,218371Table1ListoftestingstrainsStrainOriginCulturegenerationObversecharacteristicsofthestrainRearcharacteristicsofthestrainTypePFCF-OInfectiveC.formosanus3,Grayishrosered,concavoconvexandfluffypowdercushion,15mmCreamyyellow,manyhummockyhumpina15mmradiusofcirclefromthecentertotheperipheryofthestrainMycelialsporeformingPFCFDPFCFOSubculurefromPFCFO25,Grayishrosered,centerconvexfluffypowdercushion,Creamyyellow,turnpaleevenlyfromthecentertotheperipheryofthestrainMycelialformingPFCFD58PFCFDIsolatedfromPFCFD28,Grayishrosered,evenlyandlowpowdercushion,Creamyyellow,turnpaleevenlyfromthecentertotheperipheryofthestrainSporeformingPFCFD20PFCFDIsolatedfromPFCFD28,Grayishrosered,centerconvexfluffypowdercushion,Creamyyellow,turnpaleevenlyfromthecentertotheperipheryofthestrainMycelialformingPFCFD50PFCFDIsolatedfromPFCFD28,Grayishrosered,centerconvexfluffypowdercushion,Creamyyellow,turnpaleevenlyfromthecentertotheperipheryofthestrainMycelialforming90%,L!D=14!1024h,,,25,,1.6DPS[11]Duncan22.1,PFCFO(4),(6),,PFCFO2.7107/mL,62.59%,PFCFD;1.16,(1.02~1.07),PFCFO2,97.74%,PFCFD,19.86%(2)2.22(y)(4)(x)y=31.9x-106.8(r=0.8477r0.01=0.4960,P=0.0251)y=42.8x-36.8(r=0.7735r0.01=0.5900,P=0.0097)y=3.8x-146.5(r=0.8885r0.01=0.5900,P=0.0084)y=477.7x-466.7(r=0.8420r0.01=0.6230,P=0.0056),(6)(x)y=-16.9x+360.9(r=-0.8157r0.01=0.4960,P=0.0256)(1),2,,2193:22Table2BiologicalcharacteristicsofIsariafumosoroseastrainsandthecorrectedmortalityofthe2ndinstarlarvaofPlutellaxylostellaStrain4Growthrateinformer4days(mm/d)6Growthrateinlater6days(mm/d)Sporulation(107conidia/mL)Sporegerminaterate(%)(r)ExtracellularproteaselevelCorrectedmortality(%)PFCFO6.22∀0.04a15.98∀0.12c2.70∀0.17a62.59∀0.04a1.16∀0.03a97.74∀0.01aPFCFD4.56∀0.04b18.87∀0.27b1.69∀0.02c46.07∀0.07b1.04∀0.01c19.86∀0.10dPFCFD584.94∀0.03b18.45∀0.07b2.34∀0.13b47.56∀0.05b1.07∀0.02b51.44∀0.05bPFCFD203.87∀0.11c20.13∀0.16a1.17∀0.11d48.45∀0.02b1.02∀0.01c30.94∀0.08cPFCFD504.26∀0.07b19.75∀0.18b1.05∀0.13d48.39∀0.03b1.03∀0.01c26.65∀0.03c:Means∀SE,(Duncan,P0.05)Note:DatainacolumnarepresentedasMeans∀SE,followed