First report of dry rot of potato caused by Fusarium proliferatum in India

Potato stands first as a non-cereal food crop for global consumption purposes. During the year 2019–20, dry rot disease symptoms were observed on potato tubers of the cultivar ‘Kufri Pukhraj’ kept in a cold store in the Moga district of Punjab State of India. Initial symptoms were observed as wrinkled and shriveled tubers with necrotic lesions on the tuber skin. The cottony white mycelial growth was also evident on some cracked tubers. During the incubation of these tubers at 25 °C for 7 days, the symptoms were more prominent with intensive whitish mycelial growth throughout the tuber. The pure culture of isolated fungus showed sparsely white colonies, which turned violet after 2 weeks. The oval or club-shaped microconidia were abundantly present on monophialides and multiphialides. The slender or straight macroconidia having 3–5 septa were also observed. The long and short chains of microconidia were observed in the fresh colonies. The molecular identification based on translation elongation factor 1 α (TEF1 α) and internal transcribed spacer region primers revealed the fungus identity as Fusarium proliferatum. The pathogenicity test was also performed to prove the Koch postulates on the initially identified host cultivar. To the best of our knowledge, this is the first report of dry rot disease caused by Fusarium proliferatum in India.