Shandong Science ›› 2025, Vol. 38 ›› Issue (4): 67-77.doi: 10.3976/j.issn.1002-4026.20240080

• Microbiology of Agriculture • Previous Articles     Next Articles

Identification of pathogens causing root rot of American ginseng in Weihai and screening of biocontrol Trichoderma strains

ZHANG Jiahui1(), LI Hongmei1, CHEN Dongmei2, YANG Han1, HU Jindong1, LI Jishun1, WEI Yanli1,*()   

  1. 1. Ecology Institute of Shandong Academy of Sciences, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250103, China
    2. Zhangqiu Bureau of Agriculture and Rural Affairs, Jinan 250200, China
  • Received:2024-06-21 Online:2025-08-20 Published:2025-08-05
  • Contact: WEI Yanli E-mail:z17864730072@163.com;weiyl@sdas.org

Abstract:

In order to explore effective biological control resources for the cultivation of American ginseng, identification of pathogen species and screening of highly effective biocontrol Trichoderma were carried out for the root rot of American ginseng in Weihai. Through tissue isolation, morphological analysis, and dual-gene (ITS/TEF1-α) phylogenetic analysis, the pathogens responsible for root rot were isolated and identified. The pathogenicity was confirmed using Koch's postulates, and the abundance of key pathogens in the rhizosphere soils of diseased and healthy plants was analyzed through quantitative polymerase chain reaction (qPCR). Finally, biocontrol Trichoderma strains were screened through plate antagonism assays and pot experiments. The results showed that 125 fungal strains were isolated from the rotten roots of American ginseng, with Fusarium being the dominant genus, accounting for 70.91%. Four pathogenic strains were identified: F. solani (XYS-1), F. oxysporum (XYS-2), F. proliferatum (XYS-33), and Alternaria alternata (XYS-44). qPCR analysis revealed that the abundance of F. solani, F. oxysporum, and A. alternata in the rhizosphere soils of diseased plants was 42.35%, 13.80%, and 33.44% higher, respectively, than healthy plants. Three Trichoderma strains showed significant inhibitory effects against these pathogens. Specifically, strain HB20111 inhibited F. solani by 66.94%, strain KZ23651 inhibited F. oxysporum by 76.00%, and strain QT20747 inhibited A. alternata by 65.20%. Greenhouse pot experiments showed that Trichoderma inoculation increased plant height, root fresh weight, chlorophyll content in the leaf, and root activity of American ginseng while reducing the incidence of root rot. In this study, we identified the pathogens causing the root rot of American ginseng in Weihai and screened biocontrol Trichoderma strains, which provided a foundation for sustainable control of the root rot of American ginseng in this region.

Key words: American ginseng, root rot, pathogen identification, pathogen abundance, Trichoderma, biocontrol

CLC Number: 

  • P41