Investigation of the spore production of Paecilomyces spp. isolated from several agricultural soils with the biocontrol activily against Spodoptera litura

Abstract

Paecilomyces is a fungus that parasites on various insect species. However, Paecilomyces has not been widely studied and applied in Vietnam. In this study, Paecilomyces spp. were isolated from several agricultural soils and identified based on the morphology and 28S rDNA gene sequencing. Biocontrol activities of Paecilomyces were measured in vitro against Spodoptera litura. The Paecilomyces strains with high biocontrol were studied for the spore acquisition on semi-solid culture. There were five isolated strains belonged to Paecilomyces (strain F01 belonged to P. javanicus, strain F02 belonged to Paecilomyces sp., strain F03 belonged to P. lilacinum and strains F04 and F05 belonged to P. lilacinus) from 33 different samples. In particular, both of F03 and F04 performed high biocontrol activity against S. litura after 10 days of inoculation. Optimization of spores production medium showed that F03 and F04 grew well on a defined semi-solid medium whose the main components were unpolished rice, wheat bran and husk of 55% humidity. The results indicated that the native strains of Paecilomyces were potential for applications to produce bioproducts for pest management strategies.