Isolation and characterization of endophytic and rhizosphere bacterial antagonists of soft rot pathogen from Pinellia ternata

• Published in: FEMS microbiology letters Vol. 295; no. 1; pp. 10 - 16
• Main Authors: Hu, Xiufang, Fang, Qionglou, Li, Shixiao, Wu, Jinguang, Chen, Jishuang
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.06.2009; Wiley-Blackwell; Oxford University Press
• Subjects: Antagonists; Antibiosis; Bacteria; Bacteria - isolation & purification; Bacteria - metabolism; Bacterial Physiological Phenomena; Bacterial plant pathogens; Biological and medical sciences; Biological control; China; Endophytes; endophytic and rhizosphere antagonists; Fundamental and applied biological sciences. Psychology; Generalities. Techniques. Transmission, epidemiology, ecology. Antibacterial substances, control; Herbal medicine; Microbiology; Pathogens; Pectobacterium; Pectobacterium carotovorum; Pectobacterium carotovorum - growth & development; Phytopathology. Animal pests. Plant and forest protection; Pinellia - microbiology; Pinellia ternata; Plant Roots - microbiology; Plantlets; Rhizosphere; Seedlings; Soft rot; soft rot disease; Soil Microbiology; Tissue culture; Tissues; Transplants; China; endophytic and rhizosphere antagonists; biological control; soft rot disease; Rhizosphere; Pinellia ternata; Biological control; Bacteria; Endophyte; Antagonist; Pectobacterium; Pectobacterium carotovorum; Enterobacteriaceae
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.2009.01558.x

Abstract Pinellia ternata, a traditional Chinese herb that has been used in China for over 1000 years, is susceptible to a soft rot disease, which may cause major loss of yield. The use of bacteria as potential antagonists against Pectobacterium carotovorum SXR1, the causal agent of the disease on P. ternata, was evaluated. Altogether, 1107 candidate bacteria were isolated from the rhizosphere and surface-sterilized plants of P. ternata. In Petri dish tests, 55 isolates inhibited the growth of strain SXR1, and 21 of these reduced the disease development on P. ternata slices by over 50%. Four selected antagonists significantly reduced the disease incidence on tissue culture seedlings, and also prevented the disease on the transplants. Agonist P-Y2-2 yielded a good prevention level of 81.9%. The four antagonists rapidly colonized the tissue culture seedlings and transplants, whereas greater populations of the antagonists (107–109 CFU g−1 fresh tissues) were observed in the seedlings and in the preinoculated transplants than in those inoculated during transplanting. The use of pathogen-free tissue culture seedlings pre-inoculated with antagonist may provide a strategy for production of P. ternata plantlets resistant to soft rot disease. This is the first report on the efficacy of biocontrol agents against pathogens on P. ternata.