Management of Meloidogyne incognita with the endophytic fungus Beauveria bassiana.

BACKGROUND

Meloidogyne incognita root-knot nematodes (RKNs) pose a significant threat to crops, ranking among the most dangerous plant pathogens globally. Entomopathogenic fungi (EPF) have been reported to reduce populations of plant-pathogenic nematodes, including M. incognita. Moreover, the fermentation broths of some EPF strains have displayed biocontrol activity against RKNs. However, the mechanism behind the nematicidal activity of EPF fermentation broths remains poorly understood.

RESULTS

First, using in vitro bioassays, we found that the fermentation broth of EPF Beauveria bassiana produced inhibitory effects on egg hatching and on the second-stage juveniles (J2s) survival of M. incognita RKNs. Second, using olfactometer-like bioassays, we found that the fermentation broth of B. bassiana exhibited strong repellent effects on M. incognita J2s. Third, in vivo bioassays using tomato plants inoculated with B. bassiana or added with the B. bassiana fermentation broths, confirmed the negative effect of B. bassiana on M. incognita root colonization, which was correlated with the induction of defense hormones in tomato plant.

CONCLUSION

This study demonstrates that the fermentation broths of B. bassiana not only effectively control M. incognita but also enhance plant resistance against plant-pathogenic nematodes. These findings provide a novel, eco-friendly approach for integrated nematode management, offering promising potential for sustainable agricultural practices and the development of environmentally responsible control strategies in agroecosystems. © 2025 Society of Chemical Industry.