Plant-soil feedback of an endophytic grass on a legume-Rhizobium symbiosis

GARCÍA PARISI PA, GRIMOLDI AA, DRUILLE M, LATTANZI FA, OMACINI M

Arnstadt

Workshop; 58 Jahrestagung der Arbeitsgemeinschaft Grünland und Futterbau; 2014

Arbeitsgemeinschaft Grünland und Futterbau

Plants have been shown to condition soils in a way such that the growth of the next generation can be either promoted or inhibited. These so-called plant-soil feedbacks ?referred to as ?direct? or ?indirect? depending on whether the same or a different species is affected? are thought to be mediated by plant-induced changes in belowground biotic and abiotic conditions. Fungal endophytes living in the leaves of C3 grasses (Neotyphodium, Clavicipitaceae) are symbionts that can alter chemical and biological soil properties, either by changing the quantity or quality of the biomass that enters the soil, or by allelopathic effects of root exudates. For instance, several studies have shown changes in species composition due to the presence of endophytes, mediated through changes in soil characteristics, or in the activity of soil pathogens. The aim of this study was to assess the existence of an indirect plant-soil feedback of endophyte-grass and arbuscular mycorrhizal fungi (AMF)-grass symbioses on the next generation of a legume-Rhizobia symbiosis. Specifically, we hypothesize that (i) the presence of the endophyte in a grass reduces the availability of AMF spores, that (ii) this negatively affects the establishment and growth of the, and that (iii) the response differs for legume plants with different levels of nitrogen (N) fixing bacteria. Therefore, we expect that (iv) the interaction of these three symbionts between generations has consequences for the primary productivityand source of N acquisition of the ecosystem.