Fungal filtrate of Trichoderma with nematicidal activity against Meloidogyne incognita (Kofoid & White) Chitwood

Abstract

The objective of this study was to evaluate the in vitro properties of 41 Trichoderma native strains in egg hatching and mortality of the second stage (J₂) of root knot nematode M. incognita. Trichoderma strains were grown on PDA at 30°C for eight days, and then 5 mm discs were placed in the liquid culture medium containing 200 g potato and 20 g dextrose L^-1 distilled water. A series of filtrations were performed with sterile gauze, immediately centrifuged for 5 min at 3000 rpm, Whatman paper no. 1 and through a 0.45 μm milipore filter. The in vitro assay was conducted in two stages; the first was to add 1 ml of each fungal filtrate in siraccus with 50 eggs of the phytonematode and evaluated at 72. 96 and 120 h of exposure; the second consisted in adding these same filtrates with 25 second stage juvenils (J₂) of M. incognita and its antagonistic effect was evaluated at 24 and 48 h, and the reversibility effect. The treatments consisted of 41 fungal filtrates and one control with sterile distilled water, four replicates distributed in a completely random design. The results indicated that the filtrates achieved up to 91.10 % inhibition of egg hatching of the phytonematode and up to 92.24 % mortality of J₂ of M. incognita at different exposure times to the fungal filtrates.