Biotechnology Bulletin ›› 2023, Vol. 39 ›› Issue (10): 209-218.doi: 10.13560/j.cnki.biotech.bull.1985.2023-0234

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Isolation and Identification of Apple Brown Rot Pathogen in Parts of Gansu and Screening of Antagonistic Bacteria

JIANG Jing-jing1,3(), ZHOU Zhao-xu1,3, DU Hui1,3, LYU Zhao-long2, WANG Chun-ming1,3, GUO Jian-guo1,3, ZHANG Xin-rui1,3, LI Ji-ping1,2,3()   

  1. 1. Institute of Plant Protection, Gansu Academy of Agricultural Sciences, Lanzhou 730070
    2. College of Plant Protection, Gansu Agricultural University, Lanzhou 730070
    3. Scientific Observing and Experimental Station of Crop Pests in Tianshui, Ministry of Agriculture and Rural Affairs, Tianshui 741299
  • Received:2023-03-16 Online:2023-10-26 Published:2023-11-28
  • Contact: LI Ji-ping E-mail:jingjingziyu@163.com;lijiping@gsagr.ac.cn

Abstract:

This work aims to clarify the pathogenic species of apple brown rot in Jingning county and Yuzhong county of Gansu province and to screen high-quality pathogen antagonistic bacteria for providing resources for biological control of apple postharvest diseases. The pathogens were isolated and purified by conventional tissue isolation method, verified by Koch's postulates, and identified by molecular biology method combined with morphology. The antagonistic bacteria were screened by plate confrontation, identified by morphological, physiological, biochemical and molecular biological methods, and the disease control effects of the antagonistic bacteria were determined by in vitro fruits. The results showed that the pathogens causing apple brown rot in Jingning county and Yuzhong county of Gansu province were Monilia yunnanensis. The optimal antagonistic bacterium X2-2 was Bacillus amyloliquefaciens, which inhibited(81.29±0.57)% of the mycelium of M. yunnanensis and 98.8% of the control effect of the antagonistic bacteria on the isolated fruits. It significantly inhibited the expansion rate of M. yunnanensis lesion spots of apple fruits. M. yunnanensis was the main pathogen of apple brown rot in some areas of Gansu province. The endogenous antagonistic bacterium X2-2 screened in this study had significant antibacterial effect and had the potential of being a high-quality biocontrol strain.

Key words: apple brown rot, Monilia yunnanensis, Bacillus amyloliquefaciens