FIGURE 4.

Time course of Fusarium wilt on tomato seedlings treated with different fractions isolated by exclusion chromatography from high-molecular weight metabolites of a biocontrol F. oxysporum CS-20. Prior to inoculation by pathogenic FOL strains (F37 + Fot3), roots of tomato seedlings were exposed to fractions I–V (see Figure 3) for 2 days. Control seedlings were exposed to sterile ddH₂0. The fractions were sterilized by passing through a microporous filter. After 2 days of incubation under aseptic conditions, seedlings were planted, and disease symptoms were visually monitored. Mean values of the disease index from four independent experiments, five replications a treatment in each ones, are presented. Bars represent SD.