Biocontrol of eyespot disease on two winter wheat cultivars by an anecic earthworm (Lumbricus terrestris)

Michel Bertrand (1) , Manuel Blouin (2) , Sébastien Barot (2) , Aude Charlier (1) , Damien Marchand (1) , Jean Roger-Estrade (1)

1 Agronomie
2 iEES - Institut d'écologie et des sciences de l'environnement de Paris

Eyespot is a major fungal disease of winter wheat, mostly affecting the base of the stem. The development of biological control approaches, using organisms such as earthworms, represents a potential alternative strategy for eyespot control. In a greenhouse experiment, we analyzed the response of two wheat cultivars (Soissons and Aubusson) to the presence of the pathogenic fungus Oculimacula yallundae and the anecic earthworm Lumbricus terrestris, alone and in combination. We assessed necrosis frequency, necrosis severity, wheat biomass, resource allocation and soil mineral concentrations. Disease incidence was lower in the presence of earthworms: the frequency of necrosis was 44% lower for Soissons and 70% lower for Aubusson. Necrosis severity was also lower for both cultivars (50% lower for Soissons and 80% lower for Aubusson) in the presence of earthworms. Earthworms had no detectable effect on the shoot and root biomasses of plants exposed to the fungus, but they modified resource allocation between plant organs and nutrient translocation within the plant. Our results suggest that earthworms are a potentially effective biocontrol agent for eyespot, and we discuss the possible underlying mechanisms. (C) 2015 Elsevier B.V. All rights reserved.

Mots clés: Belowground-aboveground interactions; plant-growth; field conditions; soil; Anecic earthworm Lumbricus terrestris; Biological control; Eyespot disease; Pathogenic fungus Oculimacula yallundae; Winter wheat Triticum aestivum; aporrectodea-trapezoides; humic substances; biomass; genes; expression; management; tolerance

Domaines: Sciences du Vivant [q-bio]

Michel Bertrand, Manuel Blouin, Sébastien Barot, Aude Charlier, Damien Marchand, et al.. Biocontrol of eyespot disease on two winter wheat cultivars by an anecic earthworm (Lumbricus terrestris). Applied Soil Ecology, 2015, 96, pp.33 - 41. ⟨10.1016/j.apsoil.2015.07.006⟩. ⟨hal-01241050⟩