Attempts to biologically control Fusarium Head Blight of wheat and the associated trichothecenes
- Publikations-Art
- Kongressbeitrag
- Autoren
- A. El-Hasan, B. Höglinger, F. Walker, R. T. Voegele
- Erscheinungsjahr
- 2015
- Tagungsname
- XVIII. International Plant Protection Congress (IPPC)
- Tagungsort
- Berlin
- Tagungsdatum
- 24–27 August 2015
Fusarium graminearum is regarded as the primary causal agent of Fusarium Head blight (FHB) of wheat. In addition to the extensive yield losses, kernels can also be qualitatively affected by contamination with trichothecenes which exhibit acute toxicity for humans and livestock. In the present study, the antagonistic potential of seven strains of Trichoderma (2 x T. harzianum, 3 x T. hamatum, T. virens and Trichoderma sp.) against the mycotoxigenic strain FG260 of F. graminearum were investigated both in vitro and under greenhouse conditions. All antagonistic strains were able to substantially inhibit mycelial growth of F. graminearum in dual culture, volatile and cellophane membrane assays. Two strains (T16 of T. harzianum and T23 of Trichoderma sp.) proved to be highly effective in the different assays used. For instance, in the presence of volatile metabolites emitted by T23 or T16, mycelial growth of the pathogen was retarded by 89.3% or 76.4%, respectively. Similar suppression of mycelial growth were detected when F. graminearum was inoculated on agar containing metabolites secreted by both Trichoderma strains. Formulations of all Trichoderma strains were prepared and investigated for their potency to minimize incidence of FHB and trichothecenes accumulation in wheat kernels under greenhouse conditions. The results revealed that FHB incidence was reduced when T23 or T16 were applied during anthesis by 78.6 or 66.4%, respectively. Moreover, thousand kernel weight (TKW) was negatively correlated with FHB incidence. An increase in TKW was observed in kernels treated with T16 or T23. However, all other strains showed no distinct increase in TKW compared to the infected control where Trichoderma strains were absent. Furthermore, trichothecenes analysis in the harvested kernels confirmed that some Trichoderma strains were able to degrade or inhibit the synthesis of trichothecenes. In the presence of the strain T23, deoxynivalenol (DON), 15-A-DON and 3-A-DON accumulation in the kernels were reduced by 48.2%, 45.9%, and 88.2%, respectively. All other antagonistic strains however, distributed between either moderate or slight trichothecenes inhibitors.