Screens Biocontrol Strains From Chaetomium Spp. And Studies On Biocontrol Mechanisms Of Chaetomium Spp.

Chaetomium spp.widely distribut in nature,and have a potential role in biocontrol to many plant pathogens.The author obtained 5 Chaetomium spp.in the soil matrix and litter,which can impactfully control plant pathogens,and then studied on biological control mechanisms of each.the main contents included:competitive inhibition,parasitism, extracellular bacteriolytic enzymes,secondary metabolites and inducing plants to defend to the plant pathogens.The classical morphology-based identification methods were mostly adopted andmolecular biology methods were also adopted when necessary.Eventually the 56 strains were classified into six kinds of fungi Chaetomium species,they were Chaetomium globosum,Chaetomium bostrychodes,Chaetomium funicola,Chaetomium indicum, Chaetomium hexagonosporum and Chaetomium subaffine.And Chaetomium subaffineC-44 was found the first timein the spruce needles,Chaetomium globosum C-46 and C-47 were found the first time in Pine needles,those were new records.5 strains of Chaetomium spp.were obtained which could impactfully control plant pathogens through two screening methods which were mensurating the growth of Chaetomium spp.and competitive inhibition effect on plant pathogens,those were Chaetomium globosumC-46,Chaetomium bostrychodesC-13,Chaetomium funicolaC-45, Chaetomium hexagonosporumC-37,Chaetomium subaffineC-44.Through a series of experimental biocontrol mechanisms,five strains Chaetomium spp.have a clear understanding of biological control mechanisms.There were many differences in the ways of each Chaetomium spp.controlling plant pathogens.But the adoption of nutrient competition and production of secondary metabolites were the common biological control mechanisms of each..In addition,the biological control mechanisms of Chaetomium globosumC-46 also included sparasitism and inducing plants to defend to the plant pathogens.Chaetomium hexagonosporumC-37 and Chaetomium subaffineC-44 play strong roles in inducing plant defense responses to achieve the purpose of prevention and control of pathogenic pathogens.By spraying the fungi on seedlings of Pinus yunnanensis,a series of defensive protective enzymes in conifer seedlings of Pinus yunnanensis such as polyphenol oxidase enzyme(PPO), phenylalanine ammonia-lyase(PAL),peroxidase(POD) were higher than the comparison significantly which was not sparayed the fungi.Therefore,the three Chaetomium spp.can control plant pathogens,strongly and broad-spectrumly,the biocontrol mechanisms of the three Chaetomium spp.were diversification.So in real applications of disease prevention and control,we should be preferred in these three Chaetomium sp..