The Studies On Isolation,Identification And Metabolites Bioactivity Of Endophytic Fungi Form Juglans Regia L.

Endophytie fungi were isolated from root, stem and leaf from Juglans regia L. Afterinvestigating the distribution and bioactivity, we studied the biological and chemicalcharacteristics of the representative endophytic fungi. The results and some points ofrenovation are discussed as follows:1. Systemically studied the distribution and biodiversity of endophytie fungi isolatedfrom Juglans regia L. for the first time. A total of72fungi were isolated from roots, stemsand leaves of Juglans regia L. and47fungal strains were identified according to the phologyobservation.47strains were classified into2subdivisions,3classes,4orders,6families,24genera: Monilia, Chaetomella, Hormodendrum, Corethropsis, Geotrichum, Coniothyrium,Nigrospora, Melanconium, Chromosporium, Alternaria, Phoma, Ectostroma, Coniothyrium,Fusarium, Oospora, Acinula, Sphaeropsis, Aspergillus, Rhizoctonia, Ceratobasidium,Cephalosporium, Sclerotium, Ovularia, and Myxosporium. At the level of classes,Hyphomycetes were dominant among the47strains. At the level of order, Sphaeropsidalescame in at the top, right behind the Moniliales. Alternaria, Chaetomella, Aspergillus weredominant at the level of genera. Apart from one strain belonged to basidiomycetes, the rest ofstrains were deuteromycetes. Endophytie fungi isolated from Juglans regia L. mainly existedin the leaves and stems. It was found that the amount, species and distribution of endophyticfungi varied in different parts of Juglans regia L.2. The bioassay activities of metabolic products from47strains were tested. Antagonistictests showed that14strains had better antagonistic action against eight pathogens (Botrytiscinerea, Gibberella zeae, Colletotrichum gloeosporioides, Alternaria solani, Phacidiopycniswashingtonensis, Physalospora piricola, Valsa mali, Cucumis dahliae) at the concentration10times of fermentation. Fermentation of strains G3show inhibition rates higher than75%towards eight pathogens. Strains J2, G3and Y4showed antifungal activities more than60%.The results indicated that the strains of G7, G3, J2and Y4were broad-spectrum and strongerantifungal activitives.3. The complete5.8S rDNA sequences of G3strain were cloned and sequencedrespectively, and phylogenetic tree based on5.8S rDNA sequences were constructed. Thecharacteristics of morphology showed that strain G3was identified as Ceratobasidium, the analysis of DNA sequences showed that the sequence homology of G3strain was99%withCeratobasidium. According to the above evidences, the strain G3was identified asCeratobasidium sp.. Biological characteristics research showed that the proper growthtemperature of the strain was15~30℃, the optimum temperature was25℃. The propergrowth pH of the strain was5~8, the optimum pH was6~7. The optimum carbon and nitrogensource were soluble starch and peptone, respectively. G3strains could utilize many kinds ofcarbon source and nitrogen source, but preferred organic nitrogen source and acid condition.4. GC-MS analysis showed that13compounds were identified from fermentation productof G3strain, representing97.33%of the total composition, mainly including the esterscompounds;14compounds were identified from fermentation product of Y4strain,representing89.58%of the total composition. The highest relative content of substances isdimepiperate (50.46%), which had wedding activities. Other substances are organic acidcompounds. The fermentation product of G3strain is expected to develop plant elicitors. Thefermentation product of Y4strain is expected to develop new microbial herbicide.