Submitted to: International Biofumigation Symposium
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2008
Publication Date: July 21, 2008
Citation: Zasada, I.A., Masler, E.P., Halbrendt, J.M. 2008. Behavioral Response of Meloidogyne incognita to Benzyl Isothiocyanate. International Biofumigation Symposium. Technical Abstract: One reported mechanism of plant-parasitic nematode suppression by brassicaceous cover crops is the production of isothiocyanates (ITC) in soil after biomass incorporation. While plant-parasitic nematode mortality is the objective when using these cover crops for biofumigation, very little is known about how ITCs influence nematode behavior (i.e. movement, infectivity, gene regulation). Experiments were conducted to determine the effects of sublethal doses of benzyl ITC (BITC) on Meloidogyne incognita juvenile (J2) behavior. Meloidogyne incognita J2 responded rapidly to in vitro exposure to µM doses of BITC, in DMSO/water preparations, by altering their movement behavior and movement frequency. The responses of the J2 suggested that such behaviors may affect locomotion. In subsequent experiments, M. incognita J2 were exposed to the BITC concentrations found to be effective from the in vitro studies and then inoculated onto tomato to evaluate infectivity. In related experiments, a subset of these treated nematodes was examined for the production of heat-shock proteins (HSPs). A survey of HSP70 among M. incognita, Heterodera glycines, and Xiphinema americanum revealed significant differences in constitutive levels of HSP70, suggesting responses to stress may vary among plant-parasitic nematodes. Understanding how BITC modifies nematode behavior may ultimately provide insight into better management of brassicaceous cover crops for plant-parasitic nematode management.