| Streptomyces roseoflavus Men-myco-93-63is a biological agent isolated from potatoscab disease declined soil,many researchs show that Men-myco-93-63and its metabolitehave evident antagonistic against many pathogens,such as Verticilliumdahliae,Sphaerotheca fuliginea, Botrytis cinerea et al.It also has antagonistic activityagainst root-knot nematode and sweet potato stem nematode. In this experiment,thefunction of Men-myco-93-63,including the lethal efficiency of Men-myco-93-63againstroot-knot nematode J2s,the control efficiency against cucumber root-knot nematode in thegreenhouse,the enzyme produced by Men-myco-93-63,the change of the content ofMDA,the activity of the defense enzyme in the tomato,and the dynamic changes of themicroorganism in the soil，et al.The main results were listed as following:1. According to the perineal pattern of female nematode,the root-knot nematodecollecting from Xinanhe of Dingzhou in Hebei was identified as Meloidogyne incognita.2. Relative mortality S.roseoflavus Men-myco-93-63whose spore suspension,fermentation,fermentation filtrate and crude enzyme against M.incognita were all above70%.The5×fermentation is100%,and the10×fermentation is99.61%. Relative mortalityof the crude enzyme is94.87%,it suggested the enzyme played a important role in thenematodes’ control. S.roseoflavus Men-myco-93-63has strong ability of secreting proteaseand collagenase,and it could produce serine protease.The proteinase activity is473.3637U/mL.3. In the pot experiment,both Men-myco-93-63fermentation and solid statefermentation had prevention effect on cucumber root-knot nematode disease,the controlefficacy of each treatment was higher than that of1.8%abamectin and Bacillus subtilisWP,and the5×fermentation was highest,which was33.99%.When the volume ratio ofsolid state fermentation and soil was1∶200,the control effect is23.99%.In the fieldexperiment, Both Men-myco-93-63fermentation and solid state fermentation also hadprevention effect on tomato root-knot nematode disease,and the higher fermentationconcentration,the more control effect. The control effect of the5×fermentation was61.54%,the10×fermentation and the solid state fermentation were more than50%.4. S.roseoflavus Men-myco-93-63could affect the content of MDA and activity of thedefense enzyme in the tomato,but the rule was different among each treatment.In the pot experiment,the content of MDA was lower than tomato grown in the sick soil.The activityof PPO and CAT were highest in the tomato treated by5×fermentation,and the activity ofPOD and SOD were higher than CK.The activity of POD was raised and the activity ofPPO was catabatic when the fermentation concentration was reduced.In the fieldexperiment,the change rule of the content of MDA was similar to the tomato grown in thegreenhouse.The SOD activity was raised when the fermentation concentration wasreduced,and the activity of other enzymes were higher at20×fermentationconcentration.The activity of SOD and POD in the tomato treated by fermentation werehigher than those by solid state fermentation,but lower than CK.When the volume ratio ofsolid state fermentation and soil was1∶200,the PPO and CAT activity was higher thanother treatments.5. S.roseoflavus Men-myco-93-63could improve the soil microbial communitystructure,the number of bacteria and actinomyces were raised in the short time,while thenumber of fungi was reduced.In two weeks after applying Men-myco-93-63,the quantity ofbacteria rised from2.5×10~6cfu/g to3.75×10~6cfu/g,and the number of fungi reduced from2.0×10~6cfu/g to1.0×10~6cfu/g,but the number of actinomyces increased only from1.0×10~7cfu/g to1.225×10~7cfu/g,a lower increasing range. |
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