| 摘要: |
| 【目的】分离纯化上海应用技术大学萱草种质资源圃中疑似萱草叶枯病的病原菌，并对其进行鉴定；筛选对分离病原菌生长具有明显抑制作用的杀菌剂，为萱草叶枯病的田间防治提供科学依据。【方法】采集上海应用技术大学萱草种质资源圃中疑似萱草叶枯病病叶，采用组织分离法分离、纯化病原菌，并进行回接试验验证。对分离病原菌进行菌落形态和显微形态观察，并进行rDNA-ITS序列分析，采用MEGA 7.0软件中Neighbor-joining法构建其系统进化树，鉴定其分类地位。利用带毒平板法测定50%腐霉利可湿性粉剂、75%百菌清可湿性粉剂、77%硫酸铜钙可湿性粉剂对病原菌的室内毒力。【结果】从疑似萱草叶枯病病叶中分离得到病原菌YK1，其菌落呈雪白色放射状，分子孢子为卵圆形或近椭圆形，呈麦穗状，孢子壁为黑色，内容物透明，孢子大小为(3.63～7.27) μm×（3.63～7.27） μm，孢子壁约为1.82 μm。PCR扩增获得YK1内转录间隔区（ITS）序列，系统进化分析显示，在Limonomyces属菌种大类中YK1与秆褐霉菌（Limonomyces culmigenus）聚在同一分支上。3种低毒杀菌剂对YK1均有一定抑制作用，其中75%百菌清可湿性粉剂对YK1的抑制作用最强，其有效中浓度（EC50）为0.114 7 mg/L。【结论】本次萱草叶枯病病原菌为秆褐霉菌（Limonomyces culmigenus），75%百菌清可湿性粉剂对其有较好的抑制作用。 |
| 关键词: 萱草叶枯病 病原鉴定 致病性 杀菌剂 防治效果 |
| DOI： |
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| 基金项目:上海应用技术大学 生态技术与工程学院 |
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| Identification of pathogen causing Hemerocallis leaf blight and screening of fungicides |
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CHEN Ying,HUANG Dongmei,NI Di’an,et al
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| Abstract: |
| 【Objective】The suspected pathogenic bacteria causing Hemerocallis leaf blight in the Hemerocallis germplasm resource garden of Shanghai Institute of Technology were isolated, purified,characterized and effective fungicides were screened to provide basis for field control of the disease.【Method】The suspected leaves with Hemerocallis leaf blight were collected from the germplasm nursery of Hemerocallis in Shanghai Institute of Technology.The pathogen was isolated and purified by tissue separation method.Colony morphology and microscopic morphology of isolated pathogens were observed,rDNAITS sequence was analyzed,and the phylogenetic tree was constructed by the neighbor-joining method in MEGA 7.0 software to identify their taxonomic status.The indoor toxicity of 50% pythicarb wettable powder,75% Chlorothalonil wettable powder and 77% Copper Calcium sulfate wettable powder to pathogenic bacteria was determined by the method of toxic plate.【Result】The pathogen YK1 was isolated from the suspected Hemerocallis fulva leat blight.Its colony was snow-white radion.The molecular spores on the conidiophores were in the shape of wheat ears.The spore wall was black with transparent content.The spore was (3.63-7.27) μm×(3.63-7.27) μm in size,and the thickness of spore wall was about 1.82 μm.The sequence of YK1 internal transcribed spacer (ITS) was obtained by PCR amplification.The phylogenetic analysis showed that YK1 and Limonomyces culmigenus clustered on the same branch in the Limonomyces genus.The three low-toxicity fungicides had inhibitory effect on YK1. The 75% chlorothalonil wettable powder had the best inhibitory effect on YK1 with effective median concentration (EC50) of 0.114 7 mg/L.【Conclusion】The pathogen of Hemerocallis leaf blight isolated was Limonomyces culmigenus and 75% chlorothalonil wettable powder had good control effect against it. |
| Key words: Hemerocallis leaf blight pathogen identification pathogenicity fungicides control effect |
