Distribution and characterisation of entomopathogenic fungi from Korean soils

Abstract

We investigated the occurrence of entomopathogenic fungi in 1080 soil samples representing multiple locations and conditions in Korea. Entomopathogenic fungi were isolated from soils using a selective medium containing dodine and antibiotics. Following an initial identification based on morphology, the fungal isolates were more precisely identified by the sequence of their nuclear ribosomal RNA (rRNA) internal transcribed spacer (ITS) regions. As a result, entomopathogenic fungi were found to occur in 32% (342 isolates) of the soil samples studied. The most abundant species were Beauveria spp. (125 isolates) and Metarhizium spp. (82 isolates). Entomopathogenic fungi were more often recovered from natural mountain and riparian soils than from agricultural habitats. The pathogenicity of isolated fungi was evaluated by using wax moth Galleria mellonella L. (Lepidoptera: Pyralidae) larvae. It was determined that 60% (207 isolates) of the isolates were pathogenic using this model. These entomopathogenic fungi may, therefore, have potential use against a variety of agricultural pests. This is the first study of the isolation and distribution of entomopathogenic fungi in representative sampling locations throughout Korea.