The Inhibitory Effect And Active Component Analysis Of Acremonium Sclerotigenum On Pathogenic Fungi Of Garden Plant Diseases

Acremonium has preventive effect on harmful biologies,such as bacteria,nematodes,mites.Acremonium sclerotigenum is the dominant species of Acremonium fungi,and there is a lack of research on the control of pathogenic fungi of garden plant diseases at home and abroad.In this study,A.sclerotigenum was taken as the object,and on the basis of its classification status and biological characteristics,counterculture,growth method and spore germination method,liquid chromatography-mass spectrometry,colorimetric analysis were used to study the prevention effects and mechanism of A.sclerotigenum on pathogenic fungi of garden plant diseases,the effective components of it were analyzed similaily.It provided a theoretical basis for the biological control of garden plant diseases.The results as following:1.Morphological identification,pathogenicity identification and molecular biological identification specified the status of the fungi.It was non-pathogenic to seeding of Chinese scholar tree,and was an endophytic fungus,belonging to sclerotium A.sclerotigenum of Deuteromycotina Acremonium.2.The study of biological characteristics identified that the suitable ecological conditions for growth and development of A.sclerotigenum.Under the condition of full-light and 25-30℃,the mycelial growth and spore production of A.sclerotigenum were favorable;and the appropriate p H value was 4-12,and the optimal p H value was 4-7.PDA medium was the optimum medium for mycelial growth and spore production,and arabinose and organic nitrogen were the optimum carbon and nitrogen sources.3.The study of counterculture confirmed that A.sclerotigenum had a certain inhibitory effect on pathogenic fungi of common garden plant diseases and its inhibition spectrum was wide.The inhibition rate range of 21 kinds of pathogenic fungus of garden plant diseases was 10.34%-54.04%,and the inhibition rate of Fusarium chlamydosporum and Botrytis cinerea was the best,respectly 54.0395%and 46.7741%.4.Metabolite fungistasis activity study showned that,fungistasis activities varied with different cultures,and at the same culture it varied with different days in culture.PD was the best medium in 6 kinds of medium:PD,Fries,Czapek,basic liquid,improved sabouraud medium,yeast wort glucose（YMG）.At 25±1℃,150 r/min of culture 5 days was the optimal incubation condition.5.The study on the extraction and activity determination of the fungistasis components of A.sclerotigenum showed that,different organic solvent extracts of the fungi had certain inhibition on mycelial growth and spore germination of B.cinerea.And the methanol supernatant extract had the highest activity,second was toluene organic phase extract,with an EC₅₀ value of 307.5094 mg/L,476.5286 mg/L for mycelial growth and an EC₅₀ value of 624.0709 mg/L,529.8221 mg/L for spore germination.The results showed that most of the effective components of A.sclerotigenum were fat-soluble substances.Methanol or toluene,as well as solvents between the two polarities,can be used to extract the effective components of A.sclerotigenum as a single solvent.6.The effective components of different organic solvent extracts were studied by liquid chromatography-mass spectrometry.It showed that,stearic acid and palmitic acid was the common ingredients of nine extracts,and the other 18 components（prespatane,naproxen impurity N,p-xylene,elaidic acid,pentadecanoic acid,phenolic acids,ergocalciferol,α-Linolenic acid,senkyunolide A,cinnamic acid,menaquinone-4,styrene,2.4 dimethyl benzaldehyde,1,3,5-Heptatriene,6-methyltetralin,stearamide,cumene and alicylic acid）also accounted for a large proportion in the different extracts.This indicated that the active components of the fungistasis action of A.sclerotigenum were complex,which might be composed of many components and play a combined role.7.The study on the fungistasis mechanism of A.sclerotigenum showed that the methanol extract could not only inhibit the mycelial protective enzyme activity of B.cinerea,but also improve the stress resistance of host plants.The inhibition of extracellular esterase activity on mycelial of B.cinerea was the most significant,and the stress resistance was improved by increasing the activities of esterase,phenylalanine ammonia-lyase,polyphenol oxidase and superoxide dismutase of host plant.