Efficacy of bacteriophages in controlling bacterial vascular wilt caused by Ralstonia solanacearum Smith on eggplants

Abstract

The objective of the study was selection promising bacteriophages for lysis Ralstonia solanacearum in vitro and evaluation their ability to prevent bacterial vascular wilt on eggplants under greenhouse conditions. Primary selection of promising bacteriophages from four bacteriophages as Φ54, Φ60, Φ67, and ΦBT on Ralstonia solanacearum isolated from eggplant based on plaque diameter and phage multiplication in in vitro, the result found that three bacteriophages (Φ54, Φ67, and ΦBT) expressed plaque diameter over 7.00 mm at 48 hours, and phage titer with log (pfu/ml) reach over 7.00. Continuing the survey, the efficacy of these phages in controlling bacterial wilt on eggplants in greenhouse conditions through applying each bacteriophage or cocktail of three phages suspension two times (10¹⁰ pfu/ pot/ each time) before pathogen inoculation and 7 days after pathogen inoculation through soil drenching.  As a result, all bacteriophages either single or mixture of three phages were effective in the prevention of bacterial wilt disease. Especially, phage Φ BT showed the highest disease reduction and was better than bacteriocide treatment applied with Starner 20 WP.