Study On Isolation Of Endophytic Fungi From Ginkgo Biloba And Its Biocontrol Activity Against Sclerotinia Sclerotiorum

Abstract: Sclerotinia sclerotiorum is one of the most destructive plant pathogens intheworld．It causes economically important plant disease，resulting in huge economic lossevery year. Breeding for disease resistance plant and the implementation of chemicalfungicide is one of he most efficient method. But a long time of breeding resistance corn,may lead to the emergence of new resistance genes of S. sclerotiorum. Chemicalfungicides are not conducive to safe and sustainable environment-friendly development.Biological control method should be taken to prevent and control S. sclerotiorum.1. In this reseach,307endophytic fungi were isolated from different organization ofGinkgo biloba L. The organizational separation tissue isolation rate of the old leaves,bark, new leaves, treethe root and fruit are33.2%,30.5%,18.4%,10.5%,14.5%respectively. These results indicate that the the ginkgo organization are rich in endophyticfungi, different organizations contain different amount of endophytic fungi.Confrontation culture preliminary screening againt S. sclerotiorum in plate found that93endophytic fungal strains have different inhibitory effects on S. sclerotiorum, There are2strong antagonistic effect strains against S. sclerotiorum, strain No.0011has the bestactivity on control S. sclerotiorum.2. A strain, No.0011, was isolated from the medicinal plant Ginkgo biloba, and identifiedas Chaetomium globosum by morphology and molecular biology methods. This providesthe foundation for the biocontrol reseach on S. sclerotiorum by C.globosum3. In this reseach, We extract the fermentation product of C. globosum strain No.0011which was abtained by liquid fermentation method with the addition of ethyl acetate andmethanol. In dual cultures on potato dextrose agar medium, the extraction of strainNo.0011has strong inhition on S. sclerotiorum. Bioassay chemical investigation by Gelfiltration chromatography(GFC), Silica gel column chromatography(SCC), Reversedphase column chromatography(RCC) and led to the isolation of different metabolites ofstrain No.0011, and identify their activity against S.sclerotiorum. Of the41isolatedchemical components of the metabolites,9components have strong the inhibitory effect.