Abstract: To confirm the species of potato Fusarium spp. causing potato Fusarium wilt in Gansu Province，this paper conducted isolation and pathogenicity identification on pathogens of potato Fusarium wilt collected from Shandan County；and also classification and identification combined with its morphological characteristics and molecular biological analysis．The results indicated that the 3 fungi isolates obtained from isolation could cause typical Fusarium wilt symptoms on potato according to the pathogenicity identification．Among them，3-2 macro-conidia were in a shape of sickle．There were mostly 3-5 partitions，and the size was（50-75）μm ×（4-5）μm．While，the micro-conidia were ovalize．About pathogenic fungus 1-1，color of colony surface center was changed gradually from white to red，and its edge was white in color，presenting irregular shape．Conidium was not observed．The mycelia of pathogenic fungus 3-6 were red in color．At later growth stage，the colony center surface turned yellow．The hyphae has septa．The chlamydospores were round in shape，and conidium was not observed．Combining morphological features with ITS and EF-1α gene sequences homology，pathogenic fungus 3-2 was identified as Fusarium equiseti．Potato Fusarium wilt caused by this pathogenic fungus was first reported by domestic news．Pathogenic fungi 1-1 and 3-6 were identified as Fusarium tricinctum．Potato Fusarium wilt caused by this pathogenic fungus was first reported in Gansu Province．

Key words: potato, Fusarium wilt, identification, pathogenicity

摘要： 为明确甘肃省马铃薯枯萎病菌种类，对采集自山丹县的马铃薯枯萎病病原菌进行分离和致病性测定，结合其形态学特征和分子生物学分析对病原菌进行分类鉴定。结果表明，分离得到的3 株真菌分离物，经致病性测定均使马铃薯表现出枯萎病的典型症状，其中病原菌3-2的大型分生孢子呈镰刀状，多为3～5个分隔，大小为（50～75）μm ×（4～5）μm，小型分生孢子呈椭圆形；病原菌1-1菌落表面中心由白色逐渐变为红色，边缘白色，呈现不规则状，未观察到分生孢子；病原菌3-6菌丝红色，生长后期菌落中心表面呈黄色，菌丝有隔，厚垣孢子圆形，未观察到分生孢子。结合形态学特征、ITS与EF-1α基因序列同源性，将病原菌3-2鉴定为木贼镰刀菌（Fusarium equiseti），该病菌引起的马铃薯枯萎病为国内首次报道；将1-1和3-6鉴定为三线镰孢菌（F. tricinctum），该病菌引起的马铃薯枯萎病为甘肃省首次报道。

关键词: 马铃薯, 枯萎病, 鉴定, 致病性