Molecular Ecology 12(11); 3085 (Nov 2003)
Co-existing
grass species have distinctive arbuscular mycorrhizal communities
P. Vandenkoornhuyse, K.
P. Ridgway, I. J. Watson, A. H. Fitter and J. P. W. Young
Abstract
Arbuscular mycorrhizal
(AM) fungi are biotrophic symbionts colonizing the majority of land plants, and
are of major importance in plant nutrient supply. Their diversity is suggested
to be an important determinant of plant community structure, but the influence
of host-plant and environmental factors on AM fungal community in plant roots
is poorly documented. Using the terminal restriction fragment length
polymorphism (T-RFLP) strategy, the diversity of AM fungi was assessed in 89
roots of three grass species (Agrostis capillaris, Festuca rubra, Poa pratensis) that co-occurred in the same plots of a
field experiment. The impact of different soil amendments (nitrogen, lime,
nitrogen and lime) and insecticide application on AM fungal community was also
studied. The level of diversity found in AM fungal communities using the T-RFLP
strategy was consistent with previous studies based on clone libraries. Our
results clearly confirm that an AM fungal host-plant preference exists, even
between different grass species. AM communities colonizing A. capillaris were statistically different from the
others (P < 0.05).
Although grass species evenness changed in amended soils, AM fungal community
composition in roots of a given grass species remained stable. Conversely, in
plots where insecticide was applied, we found higher AM fungal diversity and,
in F. rubra roots, a
statistically different AM fungal community.