Received: 10-12-2017 / Accepted: 16-01-2018
Antagonistic fungi, Trichoderma spp., have been reported as potential bio-control agents to control soil borne plant pathogens more effectively than chemicals.Trichodermaspp.were widelyspread in soil and rhizospehre of plants. In this study, Trichoderma spp. were isolated from nine samples of soils cultivated with annual and perennial crops in five different provinces in the North of Vietnam. Trichoderma spp. were identified based on morphology and molecular characterizations. Based on the sequence analysis of ITS region, the results showed that eight isolates were identified as T. asperellum and one isolate was T. harzianum. The results indicated that T. asperellum exhibited a high growth rate and high sporulation on three different substrates and strong inhibitory effect against pathogens that cause root rot disease by Rhizoctinia solani and Sclerotinia stem rot by Sclerotinia sclerotiorum in vitro. Moreover, biosecurity assessment showed that T. asperellum was safe in rats at 20 g/kg. Our results revealed that T. asperellum is widely distributed in Northern provinces of Vietnam.