荔枝褐斑病病原鉴定及生防菌筛选  

Pathogen identification of lychee brown spot and screening of its biocontrol agents

作　　者：丁晓 宋雨 习平根[1] 李敏慧[1] 姜子德[1] 孔广辉 DING Xiao;SONG Yu;XI Pinggen;LI Minhui;JIANG Zide;KONG Guanghui(College of Plant Protection,South China Agricultural University/National Key Laboratory of Green Pesticides/Guangdong Province Key Laboratory of Microbial Signals and Disease Control,Guangzhou 510642,China)

机构地区：[1]华南农业大学植物保护学院/绿色农药全国重点实验室/广东省微生物信号与作物病害防控重点实验室,广东广州510642

出　　处：《华南农业大学学报》2025年第2期186-193,共8页Journal of South China Agricultural University

基　　金：广东省自然科学基金(2023A1515030267);广州市科技计划(202201010410);国家荔枝龙眼产业技术体系建设项目(CARS-32)。

摘　　要：【目的】鉴定新发生的荔枝褐斑病病原种类,并进行病原菌生物学特性测定和生防菌的筛选,为该病发生规律研究及绿色防控提供依据。【方法】2021年10月采集荔枝幼树褐斑病叶片,采用病组织分离获得菌株GZ1并依据柯赫氏法则确定其致病性。通过形态学比较及内转录间隔序列(ITS)、β−微管蛋白基因(Tub2)、RNA聚合酶II第二大亚基基因(rpb2)的多序列联合构建系统发育树,明确病原菌的种类。在不同碳源、温度、pH等培养条件下,测定GZ1的生物学特性。采用平板对峙法和菌丝生长速率法测定2种生防菌枯草芽孢杆菌Bacillus subtilis XX和贝莱斯芽孢杆菌B.velezensis BS对GZ1的抑制效果。【结果】菌株GZ1是荔枝褐斑病的致病菌,其种名为嘴突凸脐蠕孢Exserohilum rostratum(Drechsler)K.J.Leonard&Sugg。该菌最适生长温度为28℃,最适生长pH为7,能利用多种碳源且蔗糖为碳源时菌丝生长最快;B.subtilis XX和B.velezensis BS均对该病原菌的生长有明显的抑制效果。【结论】本研究报道了嘴突凸脐蠕孢引起荔枝褐斑病,为荔枝新病害,研究为嘴突凸脐蠕孢引起的荔枝病害防治提供了依据。【Objective】To identify the pathogen species of newly occurring lychee brown spot,determine the biological characteristics of the pathogen,and screen biocontrol agents,so as to provide a basis for understanding the occurrence patterns of lychee brown spot and green disease control.【Method】In October,2021,leaves with severe brown spot on young litchi trees were collected.A strain of GZ1 was obtained from diseased leaves and its pathogenicity was determined based on Koch’s postulates.Morphological analysis and a phylogenetic tree based on sequences of internal transcribed spacer(ITS),β-tubulin gene(Tub2),and RNA polymerase II second largest subunit gene(rpb2)were performed to clarify the taxonomic status of this pathogen.The biological characteristics of pathogen GZ1 were determined under various culture conditions including multiple carbon sources,temperatures,and pH.Antagonistic effects of two biocontrol agents,Bacillus subtilis XX and B.velezensis BS against GZ1 were evaluated using the dual culture method and hyphal growth rate method.【Result】The strain GZ1 was confirmed as the causal agent of lychee brown spot,and it was identified as Exserohilum rostratum(Drechsler)K.J.Leonard&Suggs.The optimal temperature and pH for its growth were 28℃and 7.It could utilize various carbon sources,with the fastest hyphal growth observed in the presence of sucrose.The biocontrol agents B.subtilis XX and B.velezensis BS exhibited significant inhibitory effects on the growth of pathogen GZ1.【Conclusion】This study reports that E.rostratum is the causal agent of lychee brown spot,thereby identifies a new lychee disease.The study can provide a basis for scientific control of lychee disease caused by E.rostratum.

关 键 词：荔枝褐斑病 嘴突凸脐蠕孢 病原鉴定 生防菌 

分 类 号：S436.67[农业科学—农业昆虫与害虫防治] S476[农业科学—植物保护]