[Objective] This study was conducted to screen resources for biological control of soil-borne diseases of tomato. [Method] Antagonistic bacteria against Ral- stonia solanacearum and Fusarium oxysporum were isolated an...[Objective] This study was conducted to screen resources for biological control of soil-borne diseases of tomato. [Method] Antagonistic bacteria against Ral- stonia solanacearum and Fusarium oxysporum were isolated and purified from soil samples by dilution plating and confronting incubation on PDA plates, then the antibacterial spectrum and metabolic secretions of the bacterial isolates were measured, and their species were identified by establishing phylogenetic trees with Neighbor-Joining method. [Result] From the 60 soil samples, 10 of 59 antagonistic bacteria isolates against R. solanacearum showed inhibition zone diameter 〉 25 mm, and 4 of 30 strains against F. oxysporum exhibited inhibition rate 〉 30%. The bacteriostatic substances and antibacterial spectrum analysis on above 14 isolates revealed that four strains N23-2, N58-2, NF59-3 and NF61-1 had good antago- nism against pathogenic bacteria and fungi; 12 strains produced cellulose, 11 strains produced proteases, and 6 strains produced siderophores. The molecular identification experiments indicated that four strains were members of Paenibacillus, three strains of Streptomyces, three strains of Pseudomonas strains, and four strains of Bacillus strains.展开更多
文摘[Objective] This study was conducted to screen resources for biological control of soil-borne diseases of tomato. [Method] Antagonistic bacteria against Ral- stonia solanacearum and Fusarium oxysporum were isolated and purified from soil samples by dilution plating and confronting incubation on PDA plates, then the antibacterial spectrum and metabolic secretions of the bacterial isolates were measured, and their species were identified by establishing phylogenetic trees with Neighbor-Joining method. [Result] From the 60 soil samples, 10 of 59 antagonistic bacteria isolates against R. solanacearum showed inhibition zone diameter 〉 25 mm, and 4 of 30 strains against F. oxysporum exhibited inhibition rate 〉 30%. The bacteriostatic substances and antibacterial spectrum analysis on above 14 isolates revealed that four strains N23-2, N58-2, NF59-3 and NF61-1 had good antago- nism against pathogenic bacteria and fungi; 12 strains produced cellulose, 11 strains produced proteases, and 6 strains produced siderophores. The molecular identification experiments indicated that four strains were members of Paenibacillus, three strains of Streptomyces, three strains of Pseudomonas strains, and four strains of Bacillus strains.
