Isolation, Identification and Antifungal Activity Determination of Antagonistic Bacteria Against Pyricularia oryzae Causing Foxtail Millet Blast

Foxtail millet blast, caused by Pyricularia oryzae, is a widespread airborne disease that severely threatens the sustainable production and industrial development of foxtail millet. Developing eco-friendly and non-toxic management strategies has been widely acknowledged as a core prerequisite for establishing sustainable disease control systems. In this study, a bacterial strain NR2065B9 with prominent in vitro antagonistic activity against P. oryzae was isolated from healthy foxtail millet rhizosphere soil. Taxonomic identification via morphological characterization and 16S rRNA gene sequence homology analysis confirmed that this strain belonged to the species Pseudomonas silesiensis. Dual culture assays revealed that strain NR2065B9 exerted a significant inhibitory effect on the mycelial growth of P. oryzae. Detached-leaf inoculation assays demonstrated that strain NR2065B9 could remarkably restrict the expansion of blast lesions on foxtail millet leaf tissues. Field trials confirmed that NR2065B9 application could reduce foxtail millet blast severity compared with the controls. Collectively, these findings indicated that the antagonistic strain NR2065B9 possessed great application potential in the biocontrol of foxtail millet blast, and could be further exploited as a promising microbial resource for the development of biocontrol agents against this disease.