Biology and Fertility of Soils

, Volume 43, Issue 5, pp 541–548

Effects of a plant parasitic nematode (Heterodera trifolii) on clover roots and soil microbial communities

  • Amy M. Treonis
  • Roger Cook
  • Lorna Dawson
  • Susan J. Grayston
  • Tony Mizen
Original Paper

DOI: 10.1007/s00374-006-0133-2

Cite this article as:
Treonis, A.M., Cook, R., Dawson, L. et al. Biol Fertil Soils (2007) 43: 541. doi:10.1007/s00374-006-0133-2

Abstract

We studied the effects of the root endoparasitic nematode Heterodera trifolii on rhizodeposition and the root architecture of white clover (Trifolium repens). Rhizosphere solutions were collected from the root systems of plants growing with and without H. trifolii (200 juveniles per inoculated plant) in sand-based microlysimeters. The organic carbon (C) content of these solutions was analyzed, and they were applied to plant-free soils to investigate microbial responses. Although plant biomass was unaffected by nematodes, the architecture of the root systems was significantly altered, with a decrease in overall root length and an increase in the density of lateral branches from the primary root. The presence of nematodes reduced the concentration of organic compounds in the rhizosphere solutions but only on the final sampling date (75 days). Analysis of microbial signature phospholipid fatty acids revealed no change in the structure of the microbial communities in soils to which rhizosphere solutions were applied. However, these microorganisms did respond with changes in substrate utilization patterns (community-level physiological profiles). Microbes in soils that received rhizosphere solutions from the nematode-infected clover showed lower utilization of most substrates but higher utilization of oligosugars. These responses appear to be related to changes in roots and rhizodeposition associated with nematode infection of clover roots. The results of this study suggest that root herbivory can negatively impact carbon-limited soil microbial communities via changes in root architecture that moderate rhizodeposition.

Keywords

Belowground herbivoryCLPPsPLFARhizodepositionRoot architecture

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • Amy M. Treonis
    • 1
    • 3
  • Roger Cook
    • 2
  • Lorna Dawson
    • 1
  • Susan J. Grayston
    • 1
    • 4
  • Tony Mizen
    • 2
  1. 1.The Macaulay InstituteCraigiebucklerUK
  2. 2.Institute for Grassland and Environmental ResearchAberystwyth Research StationAberystwythUK
  3. 3.Department of BiologyUniversity of RichmondRichmondUSA
  4. 4.Department of Forest SciencesUniversity of British ColumbiaVancouverCanada