Isolation and Identification of Pathogenic Bacteria of Zanthoxylum nigrosis and Indoor Screening of Control Agents
Tian Fengming
Chen Qiang
Ma Miao
Wang Guobin
Ye Wenbin
Abstract：To identify the primary pathogenic fungus responsible for Zanthoxylum black mold disease,this study employed tissue isolation,Koch's postulates,morphological and molecular biological methods,and myce-lial growth rate assays to isolate and purify the pathogen,determine its pathogenicity,clarify its taxonomic sta-tus,and screen potential fungicides under laboratory conditions.As a result,a dominant pathogenic strain desig-nated as HJ-6 was isolated from infected leaves and identified as Aspergillus niger.The results of indoor toxicity tests revealed varying inhibitory effects of eight fungicides against A.niger,and the efficacy ranked in descend-ing order of flusilazole＞oxpoconazole＞fluoxastrobin＞prochloraz＞pyraclostrobin＞trifloxystrobin＞pyra-clostrobin＞Pseudomonas fluorescens.Flusilazole exhibited the strongest inhibition(EC50=0.082 7),followed by oxpoconazole(EC50=0.316 9),fluoxastrobin(EC50=0.371 5),and prochloraz(EC50=0.593 1).In contrast,pyraclostrobin,trifloxystrobin and pyraclostrobin showed notably weaker effects and did not recommend for field applications.The four selected fungicides demonstrated high efficacy and low toxicity,providing practical guid-ance for the control of Zanthoxylum black mold disease in actual production.
Keywords：Zanthoxylum nigrosisBlack mold diseaseKoch's ruleAspergillus nigerVirulence test
Publication Date：2025-10-30
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：6( 143-148 )