Determination Of Host Range And Resistance Analysis Of Pathogenic Bacteria Of Flammulina Filiformis Soft Rot

At present,Flammulina filiformis is the largest mushroom in the factory production in China,and some diseases will occur.Soft rot was a relatively common disease in F.filiformis production,which had been found in many areas.For the factory production,once it occured,the economic loss was still large.In this paper,the biological characteristics,host range,pathogenicity and resistance mechanism of F.filiformis were studied,in order to diagnose the disease and pathogenicity.In this paper,the pathogen was isolated,purified and identified by morphology combined with r DNA-ITS molecule.The results showed that the pathogen of F.filiformis was C.varium.The pathogenicity of C.varium pathogen was verified,and the result was consistent with that of F.filiformis.In order to study the growth characteristics of the C.varium,which is the pathogen of F.filiformis soft rot,PDA medium under different conditions was used to analyze the factors affecting the germination of mycelia and conidia.The results showed that different conditions had significant differences on the growth of mycelium.Fructose was the most suitable carbon source and yeast powder was the best nitrogen source.When the nitrogen source was urea,the hypha did not germinate.At the same time,the C.varium absorption of monosaccharide was higher than that of disaccharide and polysaccharide,and the utilization rate of organic nitrogen source was higher than that of inorganic nitrogen source.When the optimum temperature is20 ℃ and p H 7.0,the mycelium grows best;when the spore germinates,the optimum temperature is 20℃ and p H 6.0.The host range of F.filiformis soft rot was determined.The results showed that C.varium was easy to infect F.filiformis,Pleurotus ostreatus,Pleurotus eryngii and Hypsizygus marmoreus,but its pathogenicity to Pholiota nameko was not obvious,and it was not pathogenic to Lentinus edodes.We studied interactions between C.varium from mushroom(F.filiformis)and some edible fungi.Using hyphal interference,fermentation filtrate,and fruiting body dipping sauce culture.The results showed that the fruiting body extracts of F.filiformis,P.ostreatus,P.eryngii and H.marmoreus mushrooms can promote the growth of C.varium.The extract of L.edodes fruiting body can inhibit the growth of C.varium.The fermentation filtrate of C.varium can inhibit the growth of the mycelia of the tested edible fungus.Through the determination of defense enzyme,the activity of enzyme in the body of F.filiformis during normal growth has little change and the floating trend is the same.After inoculated pathogen,F.filiformis was damaged by the pathogen,which led to the activation of the enzyme defense system,thus promoting the activities of five enzymes,polyphenoloxidase,catalase,peroxidase,phenylalanine ammonia lyase and superoxide dismutase.After a certain time,the maximum value can be generated.There was a significant difference in enzyme activity between inoculated and uninoculated pathogens of F.filiformis(P<0.05).The change range of enzyme activity of F.filiformis L3005 was larger than L3002 and L3003,and the activity value was higher than the two.It is suggested that the resistance of F.filiformis to soft rot is closely related to the defense enzyme system.Moreover,the time before and after the peak can be used as an important physiological and biochemical index of F.filiformis resistance.