Isolation， identification and antimicrobial activity of endophytic fungi from Polygala fallax Hemsl

【Objective】Endophytic fungi with antagonistic effects were isolated，purified and identified from the wild Polygala fallax Hemsl，which provided theoretical basis for further exploring the potential utilization value of endophytic fungi of P. fallax.【Method】The endophytic fungi were isolated and purified from wild and healthy P. fallax by tissue block separation method，and were classified and identified by morphology and molecular biology. Plate confrontation method was used to screen and determine the activity of endophytic fungi against Fusarium solani， Phyllosticta zingiberi， Scrophularia ningpocnsis， F. moniliforme Sheld.， Botrytis cinerea Pevs. and Aspergillus niger.【Result】In this study，99， 183 and 109 strains of endophytic fungi were isolated and purified from the roots，stems and leaves of 17 wild P. fallax. After identification，it was divided into 62 taxa，among which 57 taxa belonged to 33 genera，22 families，12 orders，4 classes and 2 phyla，and the rest 5 were undetermined taxonomic status. The total colonization rate and isolation rate were 77.17% and 40.94% respectively. The colonization rate and isolation rate of endophytic fungi in stem（36.44% and 19.16%）were significantly higher than those in root（31.94% and 10.37%）and leaf（8.80% and 11.41%）. The results showed that 8 strains of endophytic fungi had more than 50.00% inhibition rate to more than 4 kinds of plant pathogens. Among them，LCRPH-27 had the strongest inhibitory effect on F. solani，with the inhibition rate of 40.47%. LCSMBA-1 had the strongest inhibitory effect on P. zingiberi and A. niger with the inhibition rates of 68.07% and 65.37% respectively. LCSMBA-153 had the strongest inhibitory effect on S. ningpocnsis with the inhibition rate of 75.60%. LCRPH-9 had the strongest inhibitory effect on B. cinerea with the inhibition rate of 88.50%. LCLF-88 had the strongest inhibitory effect on F. moniliforme with the inhibition rate of 81.23%.【Conclusion】The endophytic fungi of P. fallax are rich in resources and diversity，and have good antibacterial activity. And its metabolites have great potential development and application value in the production of natural drugs or biological control.