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.