广西师范大学学报（自然科学版）2025，Vol.43Issue(1)：39-47,9.DOI:10.16088/j.issn.1001-6600.2024040701
柑橘溃疡病菌的分离鉴定及其微生物源抑制剂筛选
Isolation and Identification of Xanthomonas citri subsp.citri and Screening of Microbial Derived Inhibitors
摘要
Abstract
In this paper,the citrus canker pathogen,was isolated and identified,and the inhibitory activity of endophytic fungi associated with Stephania dielsiana Y.C.Wu against the pathogen was studied,which will lay a foundation for the development of microbial control agents for citrus canker disease.The pathogenic strain KY(F)was isolated from the infected Orah citrus leaves with canker disease using tissue isolation and streak plate methods.The bacterial colonies on NA medium were yellow,round,viscous,full edge,glossy,and slightly raised on the surface.After staining and morphological observation,it was found that it is a gram-negative bacterium with polar single flagella and a capsule.The PCR results showed that strain KY(F)could amplify a target band of expected size(413 bp),with a unique conserved protein gene similar to that of citrus canker pathogen.According to the Koch's rule,the pathogen was inoculated to healthy detached leaves of Orah citrus,and typical symptoms of citrus canker disease was formed.The results indicated that strain KY(F)was a citrus canker pathogen.The inhibitory activity of ethyl acetate extracts from 18 endophytic fungi isolated from S.dielsiana against this pathogen was determined using the toxin plate method.When the test concentration was 5 g/L,all 18 extracts could completely inhibit strain KY(F),with a MIC value ranging from 0.312 5 g/L to 5 g/L.The extracts of six endophytic fungi(Stdif6,leaf-7,leaf-9,J-10,J-29,and Y-10)showed the highest inhibitory activity against strain KY(F),with MICs ranging from 0.312 5 g/L to 0.625 g/L,all less than 1 g/L.Next were extracts of 5 endophytic fungi(J-8,J-21,J-36,Y-64,and YB-5),with MICs all at 1.25 g/L,all less than 2 g/L.Extracts of Stdif9 and Y-66 also had high inhibitory activity against citrus canker pathogenic strain KY(F),with MICs both at 2.5 g/L.The inhibitory activity of the five extracts,leaf-11,Y-51,Y-59,YB-25,and YB-26,against strain KY(F)is lower than that of other extracts,with MICs all at 5 g/L.The research results laid a foundation for the application of secondary metabolites of endophytic fungi associated with S.dielsiana in the prevention and control of citrus canker disease.关键词
柑橘溃疡病菌/血散薯/内生真菌/抑菌活性/活性物质/生物防治剂Key words
Xanthomonas citri subsp.citri/Stephania dielsiana Y.C.Wu/endophytic fungi/inhibitory activity/active substances/biological control agents分类
农业科技引用本文复制引用
刘铭希,李奇聪,冉川,张丝,施慧露,邓志勇,骆海玉,邓业成..柑橘溃疡病菌的分离鉴定及其微生物源抑制剂筛选[J].广西师范大学学报（自然科学版）,2025,43(1):39-47,9.基金项目
广西自然科学基金(2021GXNSFAA196064) （2021GXNSFAA196064）
广西重点研发计划(桂科AB21196065,桂科AB22080071) （桂科AB21196065,桂科AB22080071）
