BIOLOGICAL PROPERTIES OF BACTERIOPHAGES SPECIFIC TO BLACKROT PATHOGEN OF BRASSICAS XANTHOMONAS CAMPESTRISPV. CAMPESTRIS

摘要

Nine isolates of bacteriophages X. campestris pv. campestris were obtainedfrom soil samples collected in the fields under head cabbage crop with outbreak of black rot of brassicas. The isolates had strong lytic effect against 46.2—68.8% of 64 the tested X. campestris pv. campestris strains. Microscopic characterization confirmed that all the bacteriophages were short-tailed phages with the head diameter of 46.6 ±2.2 nm, with the tail length 134.7 ± 8.3 nm, and were assigned to the family Siphoviridae. Pre-treatment of black-rot pathogen infected seeds with the bacteriophages resulted in significant decrease in the pathogen viable cell concentration in seed extracts, and 2.0—4.1 times reduction of disease rate of cabbage seedlings compared to thecontrol.