One of the most promising novelties for control of crop pests are natural compounds with antifeedant activity, which act by interfering with insect host-selection behavior. In previous behavioral and electrophysiological tests, cultures of the soil fungus Trichoderma citrinoviride strain ITEM 4484 showed a significant antifeedant activity towards different species of aphids, including Schizaphis graminum (Rondani) and Myzus persicae (Sulzer) (Hemiptera: Aphididae). Several antifeedant metabolites were purified from rice cultures of ITEM 4484. All of them were lipophilic and low molecular weight compounds and were characterized by means of spectroscopic techniques (essentially NMR), ES MS and chemical methods. They belong to different chemical families. Of special interest are some long-chain alcohols, either saturated or unsaturated, which in behavioral assays showed a significant dose-dependent antifeedant activity against the aphid Rhopalosiphum padi, a widespread parasite of cereals.The behavioral tests were carried out with both the winged and the wingless forms: the winged forms were sensitive at lower concentrations than the wingless forms. In a subsequent study, antifeedant effect against R. padi was found also in other long-chain alcohols, chemically related to those isolated from the fungus: for all of the active compounds an international patent was filed. These results widen the range of aphid species known to be susceptible to the antifeedant action of T. citrinoviride metabolites and prompt further studies on the use of these compounds in farming practice.
From the soil fungus Trichoderma citrinoviride, bioactive metabolites with antifeedant activity with potential use in the control of aphid pests (PTC patent pending IB2012/052383)
Ganassi S;
2012-01-01
Abstract
One of the most promising novelties for control of crop pests are natural compounds with antifeedant activity, which act by interfering with insect host-selection behavior. In previous behavioral and electrophysiological tests, cultures of the soil fungus Trichoderma citrinoviride strain ITEM 4484 showed a significant antifeedant activity towards different species of aphids, including Schizaphis graminum (Rondani) and Myzus persicae (Sulzer) (Hemiptera: Aphididae). Several antifeedant metabolites were purified from rice cultures of ITEM 4484. All of them were lipophilic and low molecular weight compounds and were characterized by means of spectroscopic techniques (essentially NMR), ES MS and chemical methods. They belong to different chemical families. Of special interest are some long-chain alcohols, either saturated or unsaturated, which in behavioral assays showed a significant dose-dependent antifeedant activity against the aphid Rhopalosiphum padi, a widespread parasite of cereals.The behavioral tests were carried out with both the winged and the wingless forms: the winged forms were sensitive at lower concentrations than the wingless forms. In a subsequent study, antifeedant effect against R. padi was found also in other long-chain alcohols, chemically related to those isolated from the fungus: for all of the active compounds an international patent was filed. These results widen the range of aphid species known to be susceptible to the antifeedant action of T. citrinoviride metabolites and prompt further studies on the use of these compounds in farming practice.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
