Nematicidal effects of some Fusarium toxins
AbstractInteraction among Fusarium diseases and plant parasitic nematodes on cultivated crops have mainly been studied with particular attention to their interrelationships in the rhizosphere of the host plants, to the enhancement of Fusarium wilt in the presence of nematodes or to the break-down of resistance produced by the nematode attack (Powell, 1971; Orion and Hoestra, 1974; Palmer and MacDonald, 1974; Pitcher, 1974; Nordmeyer and Sikora, 1983; Mai and Abawi, 1987). Factors affecting the behaviour of these pathogens in nature often give rise to a complex of results that cannot be completely evaluated without considering the occurrence of all the variables involved. Some nematological experiments consider the ability of Fusarium spp. to produce toxic compounds and their effect on the different life stages of many species of plant parasitic and saprophytic nematodes (Krizkova et aI., 1979; Mani and Sethi, 1984). All these findings mainly indicate that some unidentified toxins, sugars or aminoacids, probably present in the filtrates used, were responsible for the death of the nematodes. The ability shown by several species and strains of Fusarium spp. to produce mycotoxins (Maras as et al., 1984), could play an important role in affecting nematode behaviour or interfering with the life stages. The present investigation was undertaken to determine the effect of some Fusarium toxins on the hatching of eggs of the root-knot nematode Meloidogyne incognita (Kofoid et White) Chitw.