Entomopathogenic fungi from paddy soils suppress a major insect pest and enhance rice growth under greenhouse conditions

Abstract

Intensive agrochemical use in rice cultivation poses environmental and health risks, emphasizing the need for sustainable alternatives. The development of biocontrol agents that can simultaneously suppress pests and enhance rice growth and production is particularly needed. In this study, we investigated the functionality of Hypocrealean entomopathogenic fungi (EPF) isolated from paddy soils across Thailand to suppress a major insect pest, the brown planthopper (Nilaparvata lugens) and to promote rice growth. Seventy-five EPF strains were isolated from paddy soils, primarily identified as belonging to Metarhizium and Purpureocillium genera. Two Metarhizium strains (MY13317.02 and MY13317.32), belonging to M. pingshaense sensu lato complex, exhibited strong virulence against N. lugens in vitro and demonstrated high phosphate-solubilizing activity, significantly enhancing rice growth, yield and photosynthetic performance under greenhouse conditions. The findings highlight the promising potential of these Metarhizium strains as multifunctional bioinoculants for sustainable rice agriculture, combining plant growth promotion with biocontrol efficacy. © 2025 The Authors