Antifungal Potential of Endophytic Bacteria from Lavender (Lavandula angustifolia) Against Fusarium culmorum and Neoscytalidium dimidiatum Under Greenhouse Conditions

Abstract

This study investigated the antifungal potential of endophytic bacteria (EB) isolated from lavender (Lavandula angustifolia) against two phytopathogenic fungi Fusarium culmorum and Neoscytalidium dimidiatum under greenhouse conditions. Seventy EB isolates were obtained and subjected to phenotypic characterization and enzymatic activity profiling. Through 16S rRNA gene sequencing, five isolates were identified as Bacillus sp. (Lvt24, Lvt25, Lvt32, Lvt58 and Lvt62). Greenhouse experiments showed lavender plants treated with a mixture of Bacillus sp. isolates (Lvt24 + Lvt62) via root dipping and soil application grew better than other treatments and the control. Similarly, Bacillus sp. (Lvt25) application alone improved plant health and growth. Plants inoculated with N. dimidiatum had 81.07% disease incidence and 77.7% severity, while those inoculated with F. culmorum had 88.43% disease incidence and 81.6% severity, indicating a high level of infection. Inoculating with the pathogens and Lvt25 isolate reduced disease incidence and severity by 56.2 and 57.9% respectively, compared to control plants infected with N. dimidiatum, and by 57.7 and 57.8%, respectively, compared to control plants infected with F. culmorum. These findings indicate that Bacillus sp. Lvt25 isolate has a beneficial effect in reducing disease against these pathogens and has the potential to be a biological control agent.