ISOLATION AND PARTIAL-PURIFICATION OF A PHYTOTOXIN RELATED TO PATHOGENIC VERTICILLIUM SPECIES

The low molecular weight metabolites are considered as phytotoxins of pathogenic Verticillium species. The resin, Amberlite XAD-4 was used for isolation of toxin from log-phase culture fluids of the fungus. The toxin was purified further using gel permeation. The isolated toxin induced chlorosis and necrosis in detached-leaflets of susceptible tomato and potato cultivars similar to natural symptoms. The metabolite is polar, multifunctional, heat stable, cold labile with molecular weight less than 1000. The activity was retained in dried samples of the crude filtrate and kept at room temperature for up to 8 months.