Nitrogen and phosphorus acquisition by the mycelium of the ectomycorrhizal fungus Paxillus involutus and its effect on host nutrition

Authors

  • BETTINA BRANDES,

    1. Forest Ecosystem Research Centre, Institute of Forest Botany, University of Göttingen, Büsgenweg 2, D-37077 Göttingen, Germany
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  • DOUGLAS L. GODBOLD,

    1. School of Agricultural and Forest Sciences, University of Wales Bangor, Bangor, Gwynedd LL57 2UW, UK
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  • ARND J. KUHN,

    1. Institute of Biological Information Processing, Research Centre Jülich, D-52425 Jülich, Germany
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  • GEORG JENTSCHKE

    1. Forest Ecosystem Research Centre, Institute of Forest Botany, University of Göttingen, Büsgenweg 2, D-37077 Göttingen, Germany
    2. Forest Research Institute of Lower Saxony, Grätzelstr. 2, 37079 Göttingen, Germany
    3. To whom correspondence should be addressed at: School of Agricultural and Forest Sciences, University of Wales Bangor, Bangor, Gwynedd LL57 2UW, UK. E-mail: g.jentschke@bangor.ac.uk
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Abstract

The contribution of the extramatrical mycelium to N and P nutrition of mycorrhizal Norway spruce (Picea abies (L.) Karst.) was investigated. Seedlings either inoculated with Paxillus involutus (Batsch) Fr. or non-mycorrhizal were grown in a two compartment sand culture system where hyphae were separated from roots by a 45 μm nylon net. Nutrient solution of the hyphal compartment contained either 1.8 mm NH4+ and 0.18 mm H2PO4 or no N and P. Aluminium added to the hyphal compartment as a tracer of mass flow was not detected in the plant compartment, indicating that measurements of N and P transfer by the mycelium were not biased by solute movement across the nylon net.

The addition of N and P to the hyphal compartment markedly increased dry weight, N and P concentration and N and P content of mycorrhizal plants. Calculating uptake from the difference in input and output of nutrient in solution confirmed a hyphal contribution of 73% and 76% to total N and P uptake, respectively. Hyphal growth was increased at the site of nutrient solution input.

Ancillary