Identification and pathogenicity of Fusarium spp. associated with tuber dry rot and wilt of potato in Algeria

Fusarium is one of the most important genera of phytopathogenic fungi, causing potato wilt in the field and potato tuber dry rot during storage. The objectives of this study were to identify Fusarium species associated with both potato diseases in different growing regions in Algeria, and to assess their pathogenicity. Among the 152 isolates collected from symptomatic potato plants and tubers in different provinces in Algeria, 13 species of Fusarium and Neocosmospora were identified. Among these three species were isolated only from plants showing symptoms of Fusarium potato wilt (F. oxysporum, F. venenatum, Neocosmospora solani). Two species (F. culmorum, N. tonkinensis) and an isolate of Neocosmospora sp. were found exclusively in tubers with potato dry rot and the remaining ones (F. redolens, F. cf. tricinctum, F. sambucinum, F. cf. incarnatum-equiseti, F. nygamai, F. brachygibbosum and N. falciformis) were associated with both sample types. Fusarium sambucinum was the most frequent species (52.6% of isolates). Fusarium oxysporum and F. nygamai isolates were the most aggressive in the potato wilt pathogenicity test, and F. sambucinum isolates were the most aggressive in the potato tuber pathogenicity test. This is the first study identifying and characterizing potato dry rot and potato wilt pathogens in Algeria.