Media optimization for nematode-trapping fungus Orbilia jesu-laurae and its effect in managing Meloidogyne incognita

Abstract

Meloidogyne incognita is a plant-parasitic nematode that disrupts water and nutrient uptake. While the nematode-trapping fungus Orbilia jesu-laurae shows potential as a biocontrol agent, its optimal growth conditions remain unclear. Existing research has not sufficiently explored how different growth media affect the fungus’s development and efficacy. This study evaluates various media for O. jesu-laurae growth and their effectiveness against M. incognita. O. jesu-laurae was cultured on PDA, Dextrose Agar, Maltose Agar, Sucrose Agar, Tapioca Agar and Xylose Agar, with growth rates observed over 240 h. The biocontrol efficacy was tested in vitro by measuring nematode trapping and mortality over seven days. Additionally, GC-MS analysis identified secondary metabolites produced by O. jesu-laurae. O. jesu-laurae exhibited the fastest growth in PDA (8.87 cm) and Sucrose Agar (8.47 cm). It was most effective in trapping M. incognita on Sucrose Agar, followed by PDA, with up to 40 nematodes trapped and 60.2% mortality on day seven. GC-MS identified Hexadecanoic acid methyl ester, 9-octadecenoic acid methyl ester and furfural. These findings underscore the importance of media optimization in enhancing O. jesu-laurae’s biocontrol efficacy. In conclusion, PDA and Sucrose Agar are recommended for culturing this fungus to achieve optimal biocontrol outcomes. Future research should explore field applications and synergistic strategies with other biocontrol agents to further improve nematode management.