Isolation of endophytic fungi from medicinal plant Glycyrrhiza uralensis and its microbial inhibition activity

In order to explore the resource diversity and microbial inhibition activities of endophytic fungi from medicinal plant Glycyrrhiza uralensis，the endophytic fungi were isolated from root，stem and leaf of the host by tissue inoculation culture，the five kinds of pathogenic fungi，Gaeumannomyces graminis var. tritici，Colletotrichum gloeosporioides，Botrytis cinerea，Fusarium oxysporium f. sp. cucumeris，Rhizoctonia solani，and the four kinds of bacteria，Bacillus subtilis， Escherichia coli, Staphylococcus aureus，Pseudomonas aeruginosa，were used as indicators to test microbial inhibition activities of the isolates by agar plate antagonistic action and modified agar gel diffusion methods. The results indicated that twenty endophytic fungi strains were isolated from the root，stem and leaf as a whole, and the most isolates came from the root，making up 65.0% of the total, then from stem, and leaf as the least；Based on morphological characters，the isolated strains attribute to two genera，two families and five orders，and Fusidium sp.was the dominant genera, amounting to 85.0% of the total isolates；For the isolated strains fifteen strains had antifungal activities against one or more pathogenic fungi，accounting for 75.0% of the total isolates，nineteen strains showed antibacterial activities to one or more bacterial indicators，taking up 95.0% of the total isolates; There were seven strains showed inhibition activities to B. subtilis, and eight strains had inhibition activities to S. aureus and three strains expressed inhibition activities to E. coli and one strain to P. aeruginosa; Of which the strain RLEFR015 had significant differences statistically for microbial inhibition activity against B. cinerea, S. aureus（P＜0.05）, the strain RLEFR010 had significant differences statistically for microbial inhibition activity against E. coli and S. aureus（P＜0.05），the strain RLEFR002 had significant differences statistically for microbial inhibition activities against B.subtilis and S.aureus（P＜0.05），the strains, RLEFR015, RLEFR010, RLEFR002， belonging to Fusidium sp. were strong bioactive isolates. The endophytic fungi isolated from the host showed diversity and antimicrobial activities, and majorities of the strains isolated from the host had antimicrobial activities against pathogens, inclined towards being more antagonistic to S. aureus and B. subtilis, and all that indicated that endophytic fungi from G.uralensis have important resource value.