陕西省苜蓿茎点霉叶斑病病原菌的鉴定  

Identification of Pathogen Causing Phoma Leaf Spot on Medicago sativain Shaanxi Province

作　　者：李洪建[1] 李芳红[1] 史健 呼天明[1] 程积民[1] 钱永华[1] 焦锋[1] 

机构地区：[1]西北农林科技大学动物科技学院,陕西杨凌712100 [2]彬县西坡乡动物卫生监督所,陕西彬县713500

出　　处：《草地学报》2015年第6期1310-1316,共7页Acta Agrestia Sinica

基　　金：国家公益性行业(农业)科研专项经费项目(201303157);国家现代农业牧草产业技术体系(CRAS-35)资助

摘　　要：近期发现了陕西省紫花苜蓿(Medicago sativa)一种苜蓿茎点霉叶斑病,为了准确鉴定该病害,开展了一系列病原鉴定试验。病叶片典型症状为叶尖上的深褐色斑点融合扩大呈"轮纹状"病斑;病原物的分生孢子无色透明,圆柱形,无隔单胞,大小为7×1.25μm;以病原菌rDNA-ITS(核糖体DNA内转录间隔区)序列的系统发育树的分析表明,病原菌与Phoma medicaginis var.Medicaginis(DQ109960)亲缘关系最近,NJ法中的相似性达到99%,UPGMA法中的相似性为98%;离体叶片接种验证病原菌具有致病性,结果表明:苜蓿茎点霉叶斑病的病原菌为苜蓿茎点霉(Phoma medicaginis var.Medicaginis)。Phoma Leaf spot is a serious leaf disease in alfalfa,which has happened in Shaanxi Province in recently.In order to find out the pathogen of this disease exactly,the diseased leaf typical symptom was that some sepia spots together expand like a ＂annulation＂ scab,and the conidia were hyaline,cylindrical,amerospore and unicellular,and the size was 7×1.25μm.The phylogenetic tree of the pathogen nucleotide sequence of internal transcribed spacer（ITS）shared 99% similarity with that of Phoma medicaginis var.Medicaginis（DQ109960）in Neighbour-Joining（NJ）tree,or 98% similarity using unweighted pairgroup method in arithmetic means（UPGMA）tree.The inoculation of excised leaf tissue verified that the pathogen had pathogenicity.The results indicated that it was caused by Phoma medicaginis var.Medicaginis.

关 键 词：苜蓿 病原菌 RDNA-ITS 苜蓿茎点霉 离体叶片接种 

分 类 号：S41-30[农业科学—植物保护]