Screening of indigenous entomopathogenic fungal isolates on plant parasitic nematodes in China

Root-knot nematodes (RKNs), including Meloidogyne spp., are renowned as one of the most destructive plant-parasites worldwide. The culture filtrates of entomopathogenic fungi (EPF), obtained through fermentation processes and containing significant enzyme and toxins, exhibit nematicidal activity. Moreover, the host specificity of EPF is notable, with significant variations in host spectrum and virulence among different strains. Thus, screening indigenous EPF against RKNs will broaden the resource base for developing biological control pesticides. In this study, we isolated 25 EPF strains through the Galleria bait method and investigated the pathogenicity against RKNs. Amongst the 25 EPF strains, which were molecularly identified as Beauveria spp., Metarhizium spp., Purpureocillium spp., and Cordyceps spp., several exhibited promising control effects on RKNs. Three EPF culture filters (B. bassiana 25, P. lilacinum 26, and M. pinghaeuse 39) exhibited nematicidal activity that was not affected by illumination methods or temperature. This research indicates the potential of B. bassiana 25, P. lilacinum 26, and M. pinghaeuse 39 as biological agents against RKNs.