Efficacy of bacteriophages for controlling Pectobacterium carotovorum causing soft rot disease in Cruciferous vegetables

Abstract

Soft rot disease, caused by the bacterium Pectobacterium carotovorum, is considered one of the most serious pathogens affecting Cruciferous vegetables, inflicting significant damage during both the cultivation phase and post-harvest. The study on the isolation and selection of bacteriophage capable of controlling soft rot disease in Cruciferous vegetables caused by P. carotovorum was conducted under in vitro and greenhouse conditions. A total of twenty bacteriophages were isolated from soil and leaf samples collected from three provinces (Can Tho, Vinh Long and Tra Vinh) that were capable of infecting P.  carotovorum. Among them, eight phages (Φ1, Φ2, Φ3, Φ5, Φ6, Φ15, Φ17, and Φ20) demonstrated a 100% infection rate against the eight tested bacterial strains. Under in vitro conditions, four phages (Φ1, Φ3, Φ5, and Φ20) showed high ability to multiply and lyse P. carotovorum among the eight phages evaluated. In greenhouse trial, assessing their ability to control soft rot in Bok Choy, phage Φ20 exhibited disease suppression efficacy nearly equivalent to the bactericide Starner 20WP. These findings confirm the potential of bacteriophages as a promising biocontrol agent against soft rot caused by P. carotovorum in Cruciferous vegetables.