| A nominated entomopathogenic fungi1001, which was isolated from the the modern agri-culturalexperiment and demonstration base of Henan Academy of Agricultural Sciences,was investigated on itsmorphological and molecular identification, biological properties, mass-produced method, indoor and thefield control effect. The results were as follows:One highly virulent strains useful for Noctuidae larvae was acquired by means of sample collectionoutdoors, tissue isolation and screen on PDA medium..Cultured on the PDA and SMAY medium, the strain grew very slowly and the diameter of its colonyis only0.6~1.8cm with short villous hyphae in a month on PDA medium, but grown on SMAY mediumafter10days, its colonial diameter was dramaticlly2.6cm and begin to form spores after5to7days, about10to15days later, the spores will be covered with new germination hyphae, no stale and exudate, cololessor light yellow on the back.Seen from the microscope, the conidium was green, oval or cylindrical which one end was subacute,the other was slightly dull with the size about (4.5-5.2)×(2.8-3.5)μm. Sometimes, some spores linked tostring. Also, the nutrition hyphae of the strain was smooth, or a little color with transparent, no coremiumwith hyphae usually2-3μm in diameter. So, based on these messages, the strain was initially identified asNomuraea rileyi.Through the molecular biological method to identify its rDNA-ITS sequence and blasted in NCBIwebsite Genbank database, results showed that its ITS sequence is619bp. Comparing with the Nomuraearileyi MAFF830007and the other two Nomuraea rileyi strains, the homology was99%. So,1001strainwas finally identified as Nomuraea rileyi.Cultured on different carbon sourse, nitrogen sourse, C/N, vatamines and trace elements, itdemonstrated that for mycelium growth and sporulation, the the best carbon source was respectivelyglucose and melitose, the best nitrogen source was yeast, the optimal carbon-to-nitrogen ration wasrespectively15:1and30:1. Add Mn,Fe, VB3and VB12to the medium can stimulate the mycelium growthand sporulation. Cultured on different temperature, pH, illumination, humidity, inoculumconcentration and shakingrevolution and analyzed using DPS software, results were: under solid culture circumstance, the optimaltemperature, pH, illumination and humidity for growth and sporulation were30℃and25℃, pH7,8L/16Dand95%. And under liquid culture for growth and sporulation were30℃and25℃,pH7and8L/16D.Andunder liquid culture circumstance, pH6is the best for mycelium growth, when inoculumconcentration was1ml and shaking revolution was180rmp/min, reached a maximum of dry weight.Orthogonal designed experiment of four factors, five levels was adopted to screen the best solidculture combination for sporulation, the result was maltose20g/L,Yeast5g/L,Mn15mg/L, VB120.1mg/L.Using liquid-solid two-phase method to mass-produced sporulation of Nomuraea rileyi, the resultswere: with60g soybean as the matrix and add6%melitose was the best choise.Using1.14×109spore·mL-1,1.14×108spore·mL-1,1.14×107spore·mL-1,1.14×106spore·mL-1,1.14×105spore·mL-1conidial suspension to pathogencity tests on three3-instar larva Bollworm, the results wereanalyzed by SPSS software, the mortality rate was70.53%,46.4%,34.4%,22.19%and19.12%respectively,LC50was1.163×108spore·mL-1after13days and the regression equations was Y=0.383X-3.088.Nine agentia were used to do field test and the results were analyzed by DPS software, results showedthat Nomuraea rileyi1001had a better control efficiency, population decline rate and correction controleffect were76.65%and55.18%,95.15%and58.75%,99.43%and98.77%after3days,7days and14days,which was little lower than chemical pesticide-chlorantraniliprole(population decline rate and correctioncontrol effect were88.51%and63.40%after3days,99.39%and95.93%after7days,100%and100%after14days) and the control efficiency was higher than Beauveria bassiana high pollen bought on themarket. So, in conclusion, the strain had better development prosperity. |
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