Morphological and molecular characterization of Fusarium sp. causing wilt disease of isabgol (Plantago ovata Forsk.) and its management strategies

Wilt disease of isabgol (Plantago ovata Forsk.), caused by Fusarium oxysporum species complex is one of the economically important disease in India. The pathogen survive in soil on plant debris and invaded crop plants at any stage from germination to maturity and drastically imposed the production. The disease incidence influenced by several agronomical and environmental factors and varied from 10 to 60 % prevalence. The present study was carried out to confirm the pathogenicity of associated Fusarium species of wilt disease, characterization using the morphological and molecular tools and devise the of management strategies. The Fusarium oxysporum species complex induced typical wilt symptoms on mature isabgol plants whereas, damping off like symptoms on the seedling stage. The fungal colony appeared white to purplish with cottony mycelium growth on PDA. Macroconidia were oval to slightly curved shape and septate in 2-4 cells with tapering pointed ends. The phylogenetic tree constructed based on partial ITS, translation elongation factor (EF-1 alpha) and RNA polymerase II (RPB2) and Fusarium MLTS database confirmed the association of Fusarium oxysporum species complex with the wilt disease of P. ovata. Seed dressing using carbendazim (50 W P) along with the soil application of Trichoderma viride enriched neem cake mixture before sowing significantly reduce the disease incidence. To the best of our knowledge, this is the first comprehensive report on molecular characterization of Fusarium oxysporum associated with wilt disease of P. ovata.