Apatite as a P source in mycorrhizal and non-mycorrhizal Pinus sylvestris seedlings

  • Wallander H
  • Wickman T
  • Jacks G
  • 28

    Readers

    Mendeley users who have this article in their library.
  • 77

    Citations

    Citations of this article.

Abstract

The objectives of the study are firstly to test the ability of ectomycorrhizal
pine seedlings to use apatite as a P source in comparison with non-mycorrhizal
pine seedlings and secondly, to determine if there is a relation
between exudation of organic acids and the ability to use apatite
as a P source. Non-mycorrhizal Pinus sylvestris (L.) seedlings and
seedlings ectomycorrhizal with 4 different isolates of ectomycorrhizal
fungi were grown for 220 days in sand/peat filled pots with apatite
(Ca-5(F,OH)(PO4)(3)) as the sole P source. In an additional experiment,
non-mycorrhizal Pinus sylvestris (L.) seedlings and seedlings ectomycorrhizal
with 2 different isolates of ectomycorrhizal fungi were grown without
any P source for 250 days. All other nutrients were supplied in a
balanced nutrient solution. Ectomycorrhizal seedlings grew less than
non-mycorrhizal seedlings but ectomycorrhizal seedlings produced
a large external mycelium not included in the biomass estimates.
All seedlings in the present study had low shoot:root ratios compared
to seedlings growing under optimal conditions. All seedlings grown
with apatite as P source had higher foliar P concentrations (0.71-2.11
mg/g) than seedlings growing without any P source (0.57-0.75 mg/g)
indicating a significant ability to use apatite as a P source. Seedlings
colonized by Suillus variegatus and Paxillus involutus had higher
concentrations and total contents of P in shoots compared with non-mycorrhizal
seedlings, indicating significant improvement of P uptake by these
fungi in comparison with non-mycorrhizal seedlings or seedlings colonized
Piloderma croceum. No clear relationship between exudation of organic
acids and uptake of P was found. Seedlings colonized by S. variegatus
reduced the pH of the soil more than seedlings colonized by P. involutus
or non-mycorrhizal seedlings. It is suggested that S. variegatus
colonization improves the P uptake by reducing the pH of the soil
while I? involutus improves P uptake by having a greater ability
to absorb dissolved phosphate than non-mycorrhizal roots or roots
colonized by the other fungi used in the study.

Author-supplied keywords

  • Ectomycorrhiza
  • Ergosterol
  • Paxillus
  • Phosphorus
  • Suillus
  • Weathering

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text

Authors

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free