Acta Agriculturae Boreali-Sinica ›› 2025, Vol. 40 ›› Issue (6): 168-176. doi: 10.7668/hbnxb.20195721

Special Issue: Cucumber Plant protection Vegetables

• Resources & Environment·Plant Protection • Previous Articles     Next Articles

Screening of Strong Rhizosphere-colonizing Biocontrol Bacteria Based on Root Exudates and Their Application in Cucumber Fusarium Wilt Disease Management

QU Yuanhang1,2, SU Zhenhe2, DONG Lihong2, ZHANG Xiaoyun2, LI Shezeng2, GUO Qinggang2, MA Ping2   

  1. 1 College of Plant Protection,Hebei Agricultural University,Baoding 071000,China
    2 Plant Protection Institute,Hebei Academy of Agriculture and Forestry Sciences,Key Laboratory of Integrated Pest Management on Crops in Northern Region of North China,Ministry of Agriculture and Rural Affairs,P.R.China,IPM Innovation Center of Hebei Province,International Science and Technology Joint Research Center on IPM of Hebei Province,Baoding 071000,China
  • Received:2024-12-27 Published:2025-12-31

Abstract:

This study aims to establish a biocontrol bacteria screening system based on root exudates to screen biocontrol strains with strong rhizosphere colonization ability.Using this system,bacterial strains capable of synergistic control of cucumber Fusarium wilt in combination with spent mushroom substrate(SMS)were screened.The chemical composition of cucumber root exudates was modulated by pathogen stress and SMS induction.Chemotaxis,metabolic proliferation,and biofilm formation,which were colonization-related factors,were used as quantitative indicators for the tested strains.Efficient screening of rhizosphere-colonizing bacteria was achieved using capillary assays,96-well plate cultures,and biofilm formation tests.Among 200 bacterial strains isolated from the cucumber rhizosphere,significant differences were observed in chemotaxis,metabolic proliferation,and biofilm formation in response to root exudates.Using this screening system,Bacillus velezensis MTC-5 was screened as an outstanding strain across all screening indicators.Greenhouse experiments demonstrated that MTC-5 strain combined with SMS exhibited enhanced rhizosphere colonization ability and showed significant synergistic effects in disease suppression and plant growth promotion.Field trials revealed that the combined application of MTC-5 strain and SMS achieved a disease control efficacy of 74.5% against cucumber Fusarium wilt,which was 10.7,24.6 percent points higher than the efficacy of SMS or MTC-5 strain alone,respectively.It established a high-throughput biocontrol bacteria screening system based on root exudates,highlighting the critical role of root exudates in bacterial recruitment.The MTC-5 and SMS combination developed through this system demonstrated significant synergistic effects in controlling cucumber Fusarium wilt,providing new insights and technical support for biocontrol bacteria screening and application.

Key words: Biocontrol bacteria, Screening, Root exudates, Spent mushroom substrate, Cucumber Fusarium wilt, Bacillus

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Cite this article

QU Yuanhang, SU Zhenhe, DONG Lihong, ZHANG Xiaoyun, LI Shezeng, GUO Qinggang, MA Ping. Screening of Strong Rhizosphere-colonizing Biocontrol Bacteria Based on Root Exudates and Their Application in Cucumber Fusarium Wilt Disease Management[J]. Acta Agriculturae Boreali-Sinica, 2025, 40(6): 168-176. doi: 10.7668/hbnxb.20195721.

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