Skip to Main content Skip to Navigation
Theses

Contribution à l'étude de l'allocation des photoassimilats récents dans la plante et la rhizosphère chez une graminée pérenne
(Lolium perenne L.)

Abstract : The aim of our work was to study C fluxes in plant and to rhizosphere of Lolium perenne in order to explain the relation between plant functioning and rhizodeposition.
In a first part, we have determined the contribution of recently assimilated carbon to rhizodeposition. We have developed a double long-term labelling of plants shoots (14CO2 and 13CO2) in order to estimate partitioning of recent C and older assimilated C in plant and rhizosphere compartment. In contrast to previous results, older C, probably coming from remobilisation of reserve compounds, contribute significantly to rhizodeposition.
In a second part, we have evaluated, with field trials, the influence of constraint affecting plants shoots on recently assimilated C fluxes to rhizosphere (elevated CO2, defoliation). Soil nitrogen availability is the driving force of plants responses to elevated CO2 or defoliation. In autumn, a decrease of C rhizodeposition is observed for plants submitted to elevated CO2. Organics compounds released by roots are mineralised faster under elevated CO2 than under ambient CO2. Defoliation involved any change in C availability in the rhizosphere, suggesting any significant influence of this factor on rhizodeposition.
Interactions between environmental and management factors determined plant functioning and modulated C fluxes from roots which give rhizodeposition difficult to predict and to model. Net effect of elevated CO2 or defoliation on rhizodeposition are less significant under field conditions than under controlled conditions. More than quantitative contribution of rhizodeposition to soil C pool, interactions between biochemical composition of rhizodeposits and soil biological activity need to be complete.
Document type :
Theses
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-00137743
Contributor : Stéphane Bazot <>
Submitted on : Wednesday, March 21, 2007 - 4:57:13 PM
Last modification on : Wednesday, October 14, 2020 - 4:10:54 AM
Long-term archiving on: : Wednesday, April 7, 2010 - 1:40:42 AM

Identifiers

  • HAL Id : tel-00137743, version 1
  • PRODINRA : 9662

Collections

Citation

Stéphane Bazot. Contribution à l'étude de l'allocation des photoassimilats récents dans la plante et la rhizosphère chez une graminée pérenne
(Lolium perenne L.). Ecologie, Environnement. INPL - Institut National Polytechnique de Lorraine, 2005. Français. ⟨NNT : 2005INPL043N⟩. ⟨tel-00137743⟩

Share

Metrics

Record views

511

Files downloads

4543