Acta Agriculturae Zhejiangensis ›› 2025, Vol. 37 ›› Issue (7): 1469-1480.DOI: 10.3969/j.issn.1004-1524.20240565

• Plant Protection • Previous Articles     Next Articles

Screening and identification of an antagonistic fungus strain against root rot disease in tea plants and its biological characteristics

DENG Yulian1,2(), TAN Lin3, NIU Li1,2, LU Qiancheng1,2, ZHOU Linghong4, LI Guihua1,2, HU Qiulong1,2,*()   

  1. 1. Key Lab of Tea Science, Ministry of Education, Hunan Agricultural University, Changsha 410128, China
    2. College of Horticulture, Hunan Agricultural University, Changsha 410128, China
    3. College of Plant Protection, Hunan Agricultural University, Changsha 410128, China
    4. Chenzhou Institute of Agricultural Science, Chenzhou 423001, Hunan, China
  • Received:2024-06-27 Online:2025-07-25 Published:2025-08-20

Abstract:

In the present study, a fungal isolate with antagonistic effect on tea root rot pathogen was screened from the rhizosphere soil of tea plants infected by tea root rot pathogen through plate confrontation method. The isolated strain was identified by the morphological and molecular biology methods, and its biological characteristics were studied, as well as its antimicrobial spectrum, antimicrobial ability of metabolites and extracellular hydrolase activities. The results showed that the obtained strain FX2 was finally identified as Penicillium citrinum, which exhibited an inhibition rate of 72.98% against the pathogen Fusarium cugenangense of tea root rot. The strain FX2 was relatively insensitive to the carbon-nitrogen ratio. The suitable carbon source of this strain was lactose, the suitable nitrogen source was peptone or yeast extract, the optimal sulfate was MgSO4 or K2SO4. The tolerance range of this strain to NaCl was 0-140 g·L-1, the optimal pH value was 6, and the maximum withstand temperature was 60 ℃. The ultraviolet light irradiation exhibited certain inhibitory effect on the growth of this strain. The inhibition rate of this strain against other 8 plant pathogens (including Alternaria alternata, Fusarium graminearum, Exserohilum turcicum, Diaporthe citri, Fusarium oxysporum, Colletotrichum circinans, Colletotrichum camelliae, Pseudopestalotiopsis theae) were higher than 50%, indicating broad antibacterial spectrum. The inhibition rate of 5%, 10%, 15% and 20% sterile fermentation filtrate against root rot pathogen was 35.12%, 45.98%, 52.80% and 59.46%, respectively, and the inhibition rate of non-volatile metabolites and volatile metabolites against root rot pathogen was 71.73% and 22.14%, respectively. Besides, this strain also had the ability to secrete proteases, amylases, chitinases and cellulases. In conclusion, the isolated strain FX2 was a promising biocontrol resource for tea root rot.

Key words: tea tree, root rot, antagonistic fungi, inhibition rate, biological properties

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