COOMBER, SCOTT, BRIAN LEWIS & ANDREW WATKINSON.
School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK.
The effect of mycorrhizal status on the population dynamics of Vulpia
ciliata ssp. ambigua has been studied for a number of years. Field
based experiments indicate that the main benefit of an arbuscular mycorrhizal
association is in protection from pathogenic fungi rather than improved
phosphate uptake.
Here we show that the number of propagules of the pathogenic fungus
Fusarium oxysporum increase significantly in the rhizosphere of V.
ciliata ssp. ambigua when compared to the bulk soil but that this
increase does not occur if the plant is part of a mycorrhizal association.
This corresponds to the observation that internal levels of the pathogen
decrease in the presence of mycorrhiza. The mechanism of this interaction is
discussed.