Abstract

In this study, Trichoderma harzianum BI was evaluated for its capacity to reduce the incidence and pathogenicity of the root-knot nematode Meloidogyne javanica on tomato. Culture filtrates of T. harzianum BI at different concentrations, (standard, 1:1, 1:10, and 1:100) were studied.  In vitro studies revealed that hatching of M. javanica eggs were inhibited by the culture filtrates and this inhibition was positively correlated with increase in the concentration of culture filtrates. Parasitism of M. javanica eggs by T. harzianum BI ranged from 21% in control to 84% in antagonistic fungi. T. harzianum BI reduced nematode damage to tomato in vivo, too. Treatment of the soil with the antagonistic fungi and salicylic acid clearly improved nematode control when applied jointly or alone. The antagonistic fungi and salicylic acid were further tested for their ability to induce production of defense related enzymes in tomato. Earlier and increased activities of soluble peroxidase (SPOX) was observed in T. harzianum BI and salicylic acid treated tomato inoculated with M. javanica. Thus, the present study shows that in addition to direct antagonism, induction of defense-related enzymes involved in peroxidase pathway contributed to enhance resistance against invasion of M. javanica in tomato.

Key words: Biological control, Meloidogyne javanica, Trichoderma harzianum BI, peroxidase.