Investigation of Culture Filtrate of Endophytic Fungi Nigrospora Sp. Isolate Rs 10 in Different Concentrations towards Root-knot Nematode Meloidogyne Spp.

Abstract

One of the modes of action of endophytic fungi against plant pathogens e.g. plant parasitic nematode, is the production of toxic culture filtrate. Experiments were conducted to investigate the antagonistic effects of different concentrations of the culture filtrate produced by the endophytic fungi Nigrospora sp. isolate RS 10 against the root knot nematode Meloidogyne spp. Nigrospora sp. isolate RS 10 was isolated from the healthy root of a sengon plant ( Paraserianthes falcataria ). Three different concentrations of the culture filtrate were investigated using in vitro bioassays against the motile juvenile stage 2 of the root knot nematode Meloidogyne spp. Inactivation and mortality were recorded after 1, 3 and 24 hrs of exposure to culture filtrates. The mortality of the root-knot nematode Meloidogyne -J2 after 24 hrs exposure to the culture filtrate was confirmed by rinsing with sterile distilled water that demonstrated the effects of the culture filtrate treatment were irreversible, as nematodes did not recover. Nematode mortality rates after 1 to 24 hr exposure periods ranged from 80 % to 100 %. The effects of the culture filtrates on root-knot nematode Meloidogyne -J2 increased with increasing culture filtrate concentration.