Phenotypic and Nutritional Profiling of Fusarium oxysporum f. sp. cubense under in vitro: Optimal Culture Conditions and Metabolic Diversity

Abstract

Banana (Musa spp.) belongs to the family Musaceae is the important fruit crop of the world which serves as staple and cheap source of carbohydrates. Genus Musa consists of giant herbs, among these Banana CV. Ney Poovan (AB) is the major cultivating species through out south India. This crop is affected by various biotic and abiotic agents, Wilt disease caused by Fusarium Fusarium oxysporum f. sp. cubense is the destructive one. The present investigation was undertaken to know the preliminary media (Solid and Liquid) and nutritional requirement (Carbon, Nitrogen and Sulphur) of F. oxysporum f. sp. cubense under invitro conditions. Out of ten solid media evaluated, Richard’s agar (89.55 cm) and Czepek’s dox agar (80.23 cm) found as best media to support the growth of the fungus, least growth was observed in Host extract agar (21.83 cm). In liquid media evaluation, Richard’s broth (336.42 mg) and Potato Dextose broth (300.94 mg) found suitable and low growth was observed in Host extract broth (70.78 mg). In Richard’s agar, fungus produced abundant mycelial growth, smooth margins, white with pink margins, dense centre and flat edges with concentric rings. Among the seven carbon sources, Sucrose (404.28 mg) produced highest dry mycelial weight followed by Fructose (280.31 mg) compared to control (59.19 mg). Regarding nitrogen sources, potassium nitrate yields maximum dry mycelial weight (440.50 mg) followed by Ammonium chloride (421.65) compared to control (105.37 mg). In case of sulphur source as nutrient supplement, magnesium sulphate gives maximum dry mycelial weight (401.37 mg) followed by Ferrous sulphate (322.19 mg) compered to control (33.92 mg). Understanding these specific nutritional requirements help to explore novel management methods, like changing the nutrient content of the host or development of inhibitors which targets the Fusarium’s specific metabolic pathways.