Abstract:

Soft rot of Chinese cabbage is a serious bacterial disease caused by Pectobacterium brasiliense. Currently,,there are few effective products for the control of bacterial soft rot in vegetables. In order to screen biocontrol bacteria with good antagonistic effect against Chinese cabbage bacterial soft rot, this study isolated a strain of beneficial bacteria ZF510 from the rhizosphere soil of cabbage. Through morphological observation, physiological and biochemical characteristics, and multi-gene phylogenetic tree analysis, as well as pot experiments to verify the control effect of the antagonistic strain on Chinese cabbage bacterial soft rot. The results showed that the strain ZF510 was Pseudomonas donghuensis, which produced protease during the metabolic process, and had the ability to synthesize IAA, iron-loving and phosphorus-dissolving ability. Through the analysis of bacteriostatic spectrum, it was proved that strain ZF510 had significant antagonistic effects on seven pathogenic bacteria such as Pectobacterium brasiliensis and Xanthomonas campestris pv. campestris. The dichotomous dish method was used to determine that the volatile substances had inhibitory effects on the three pathogenic fungi of Rhizoctonia solani, Didymella bryoniae and Stemphylium solanacearum. The results of pot experiment showed that the symptoms of bacterial soft rot of Chinese cabbage inoculated with strain ZF510 were significantly reduced, and the control effect reached 44.56%. In summary, strain ZF510 has great potential for biological control and application prospects.

Key words:

 Pseudomonas donghuensis, cabbage soft rot, Pectobacterium brasiliense, biological control