Nitrogen supply affects arbuscular mycorrhizal colonization of Artemisia vulgaris in a phosphate-polluted field site.
Root colonization by arbuscular mycorrhizal fungi (AMF) was investigated in industrially polluted grassland characterized by exceptionally high phosphorus levels (up to 120 g kg(-1) soil). Along a pollution-induced nitrogen gradient, soil and tissue element concentrations of Artemisia vulgaris plants and their mycorrhizal status were determined. Additionally, we compared mycorrhization rates and above-ground biomass of A. vulgaris at N-fertilized and control plots in the N-poor area. Despite high soil and tissue P concentrations, plants from N-deficient plots, which were characterized by low tissue N concentrations and N : P ratios, were strongly colonized by AMF, whereas at a plot with comparable P levels, but higher soil and plant N concentrations and N : P ratios, mycorrhization rates were significantly lower. Correlation analyses revealed a negative relationship between percentage root colonization of A. vulgaris by AMF and both tissue N concentration and N : P ratio. Accordingly, in the fertilization experiment, control plants had higher mycorrhization rates than N-fertilized plants, whereas the species attained higher biomass at N-fertilized plots. The results suggest that N deficiency stimulates root colonization by AMF in this extraordinarily P-rich field site.
Blanke
Verena
V
Friedrich-Schiller-University of Jena, Institute of Ecology, Jena, Germany. blanke@uni-leipzig.de
Renker
Carsten
C
Wagner
Markus
M
Füllner
Kerstin
K
Held
Matthias
M
Kuhn
Arnd J
AJ
Buscot
François
F
D019306:Artemisia / Q000378:metabolism* / Q000382:microbiology*; D005308:Fertilizers; D038821:Mycorrhizae / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D010710:Phosphates / Q000032:analysis*; D018517:Plant Roots / Q000382:microbiology; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants
D005308:Fertilizers; D010710:Phosphates; D012987:Soil; D012989:Soil Pollutants; D009584:Nitrogen