Isolation and identification of actinomyce strain MY-4 and its antagonistic activity against pathogenic fungi of fruits and vegetables

【Objective】 The purpose of the study is to identify the antagonistic actinomyce strain MY-4 isolated from the surface of Shatang mandarin,and to evaluate the application potential of the strain for the biocontrol of fruit and vegetable diseases.【Method】 The taxonomic identification of the strain was carried out based on the morphology,physio-biochemical characteristics and the 16S rDNA sequence analysis,and the antagonistic activity of strain MY-4 was determined by confronting incubation on the PDA plates and the mycelium growth rate method.【Result】 Strain MY-4 was identified as Streptomyces albulus.The results showed that strain MY-4 and its cell-free fermentation filtrate exhibited extensive antagonistic effect on 16 fruit and vegetable pathogenic fungi.The strain exhibited the strongest antibiosis capacity with an inhibitory zone up to 17.08 mm against mycelia growth of Colletotrichum musae.Meanwhile,its culture filtrate showed the strongest antibiosis capacity against Penicillium digitatum and reduced mycelium growth by up to 98.82%.【Conclusion】 These findings show that Streptomyces albulus strain MY-4 has high activity,broad antifungal spectrum,and is expected to develop into a new biocontrol agent.