Biotechnology Bulletin ›› 2026, Vol. 42 ›› Issue (4): 310-320.doi: 10.13560/j.cnki.biotech.bull.1985.2025-0678

Previous Articles     Next Articles

Identification and Control Characteristics of Antagonistic Bacteria against Tobacco Target Spot Disease

ZHU Zhi-yan1,2(), SONG Zhi-wei2, HE Shan2, ZHANG De-qing1, HE Yong2(), TIAN Zhi-hong2()   

  1. 1.College of Elementary Education, Nantong Normal College, Nantong 226010
    2.College of Life Science, Yangtze University, Jingzhou 434025
  • Received:2025-06-27 Online:2026-04-26 Published:2026-04-30
  • Contact: HE Yong, TIAN Zhi-hong E-mail:201673036@yangtzeu.edu.cn;warers@yangtzeu.edu.cn;zhtian@yangtzeu.edu.cn

Abstract:

Objective To isolate and screen biocontrol bacteria against tobacco target spot disease. Method The antagonists were isolated and screened by plate coating method and plate confrontation method from Rhododendron simsii Planch. rhizosphere. After identification by physiological and biochemical analysis and 16S rDNA gene sequence analysis, the phylogenetic tree was constructed, and the antibacterial activities of the fermented broth and the crude extract of ethyl acetate were determined concurrently. Pot culture method was used to determine the control effect of antagonists on tobacco target spot disease, as well as the effects on the activities of malondialdehyde (MDA), antioxidant enzymes and the regulation and expression of pathogenesis related protein genes. Result A strain of Burkholderia gladioli QLDJ-1 with antagonistic effect against Rhizoctonia solani was obtained. The relative inhibition rate of QLDJ-1 against R. solani was (72.107 ± 2.788) %. Compared with the control group, the disease index of target spot of tobacco plants treated with QLDJ-1 decreased by 32.02%. The activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) increased by 33.72%, 51.45% and 17.49% respectively. The content of malondialdehyde (MDA) decreased by 62.44%. The expressions of pathogenesis-related genes such as PR1b, NmIMSP, P450-1, GST and hrs203J in the tobacco plants treated with QLDJ-1 were different from those of the control. Conclusion QLDJ-1 can effectively control tobacco target spot disease and has the potential to be developed as a biocontrol agent.

Key words: rhizosphere bacteria, Burkholderia, Rhizoctonia solani, tobacco target spot disease, biological control