张掖市山丹县马铃薯枯萎病菌的鉴定

Identification of Potato Fusarium Wilt Pathogen in Shandan County Zhangye City

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。

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-1αgene 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.