Hydrophilic compounds in culture filtrates of <i>Fusarium oxysporum</i> f. sp. <i>cubense</i> GCV [01210] induce protection to banana leave toward a main pathogen phytotoxic component

Abstract

Panama disease caused by Fusarium oxysporum f. sp. cubense (Foc), is among the most important diseases in Musa spp. Foc is a necrotrophic fungus, their phytotoxins play a role in disease development. Previously culture filtrate (FCC) 15 days incubation with differential phytotoxic activity against two Musa cultivars was obtained. From this, the main fraction with nonspecific phytotoxic activity against both cultivars was purified. In this study, the biological activity of the aqueous phase and the main phytotoxic fraction purified from organic extract of Fusarium oxysporum f. sp. cubense VCG [01210] Race 1 FCC was determined on banana leaves of cv. `Gros Michel' (susceptible) and `FHIA-01' (resistant). Foc FCC phytotoxic effect was confirmed. The aqueous phase showed no phytotoxic activity on both cultivars, while the simultaneous application of the aqueous phase with the main phytotoxic fraction induced a differential response of tissues in susceptible and resistant cultivars evaluated. The results indicated that the compounds present in the aqueous phase are required to induce the protection of leaf tissue against phytotoxic main component of the pathogen. Key words: culture filtrate, Panama disease, resistant, susceptible