Systemic infestation of Serratia entomophila AB2 through plant tissue inferred protection against insect pest and fungal pathogens

Abstract

Serratia entomophila, a Gram negative non spore forming bacteria, is commercially exploited as biocontrol agent of pasture pest, grass grub (Costelytra zealandica, Coleoptera) in New Zealand as soil inoculants. As an exception, the strain S. entomophila AB2 used in this study is having insecticidal property against pod borer (Heliothis armigera, Lepidoptera), a phyllospheric pest. Expermental results showed high rate of mortality when the pests were fed with shoot portion of ground nut developed from bacteria treated seeds. Antifungal property of S. entomophila AB2 was recorded when tested in vivo using different parts of plant developed from bacteria treated and untreated seeds. In the present study, the systemic infestation was understood by isolation and enumeration of the inoculant from different plant tissues in specific medium and an increment in number within the tissues was also observed. This is the first report of systemic spreading of S. entomophila in plant parts to provide protection against insect and fungal pests. Key