Preparation Of Soluble Concentrate Of Pleurotus Ferulae Polysaccharides And Its Control Effect On Plant Diseases

At present,plant diseases control mainly rely on chemical pesticides,but the extensive use of chemical pesticides has brought serious environmental pollution problems and drug resistance problems.Therefore,create new environmentally friendly pesticides is a important way to solve this problems.Our previous study found that the extract of Pleurotus ferulae had good inhibitory activity against plant pathogens.Based on this,this study explored the types of main active ingredients by analyzing the multi-faceted characteristics of the aqueous extract of P.ferulae.Then through screening adjuvant,physical property determination.preparation a 10.9%P.ferulae polysaccharides SL.Finally,the practical application effect was verified by field efficacy test.Detailed results are as follows:1.P.ferulae water extracts have strong inhibition on Erwinia amylovory,Rhizoctonia solani,Erwinia carotovora,Botrytis cinerea.The inhibition rates were 100%,90.28%,73.63%and 61.07%,respectively.The water extracts of P.ferulae have strong toxicity to E.amylovora and R.solani,and the EC₅₀ values were82.36 mg/L and 83.25 mg/L.The EC₅₀ values for B.cinerea and E.carotovora were 118.81 mg/L and 516.34mg/L.After treatment with different temperatures and p H,the bioactivity of the water extracts of P.ferulae did not change significantly;the active components were mainly concentrated above 3000 Da,and the polysaccharide content was 54.61%.The bioactivity of the components after alcohol precipitation and protein removal was not significantly different from that of the water extract.Therefore,the bioactive ingredient was preliminarily determined to be polysaccharides.2.Through the screening of surfactant,defoamer,antifreeze and thickener,the final formula of 10.9%P.ferulae polysaccharide SL was determined as follows:the effective component was P.ferulae polysaccharide（10.9%）;the surfactant was Tween 80（13%）,the thickener was glycerol（10%）,the defoamer was DF-604（3%）,the preservative was Methyl 4-hydroxybenzoate（0.4%）,and the sterile water was added to 100%.Through the analysis of various physical properties,it was determined that the preparation met the national quality requirements.3.Through the toxicity test in vivo,it was analyzed that the toxicity of P.ferulae polysaccharides remained at a high level after preparation and processing.The EC₅₀ of 10.9%P.ferulae polysaccharides SL against R.solani,E.amylovora,B.cinerea and E.carotovora were 89.19,98.22,162.42 and 161.62 mg/L,respectively.The field efficacy test showed that 10.9%P.ferulae polysaccharides SL had good control effects on Pear fire blight,Wheat rust and Chinese cabbage soft rot.When the dosage of the preparation was 80g/mu,the control effects on the three diseases were 71.85%,70.54%and 80.59%,respectively,which were significantly higher than those of the corresponding control group.In summary,P.ferulae polysaccharides has a good inhibitory effect on pathogenic fungi and bacteria,and has great research and development value;the 10.9%P.ferulae polysaccharides SL also showed good application effect in the prevention and control of agricultural and forestry crop diseases.Therefore,the further research and development of P.ferulae polysaccharides will lay a solid foundation for the creation of new biological pesticides in China.