Occurrence of Fusarium wilt caused by Fusarium oxysporum f. sp. spinaciae on spinach (Spinacia oleracea) in Southern Italy.

Fusarium oxysporum f. sp. spinaciae (Sherb.) W.C. Snyder & H.N. Hansen is the causal agent of Fusarium wilt of spinach (Spinacia oleracea L.), a serious disease of spinach worldwide (1). In September 2011, several plants of an unknown spinach variety grown for the production of packaged ready-to-eat salads (4th range) in a greenhouse in southern Italy (Pontecagnano, Salerno) showed yellowing of older leaves, reduced root development, blackening of the vascular tissues, and wilting of 60-day-old plants; necrotic lesions at the taproot base were occasionally present. Yield losses up to 70% were observed. Small portions of symptomatic tissues from the basal vascular stem were disinfected with sodium hypochlorite (1% active Cl2), rinsed with sterile water, and then placed on potato dextrose agar (PDA) amended with neomycin (50 ppm), chloramphenicol (50 ppm), and streptomycin (100 ppm). Pink to white colonies with a fluffy aerial mycelium rapidly developed; pale orange sporodochia containing thin walled macroc...