关键词: 马铃薯, 枯萎病, 鉴定, 致病性

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