Uptake of Phosphorus-32 by Mycorrhizal Plants

Abstract

INVESTIGATIONS based on chemical analyses have indicated that the absorption of phosphorus by pine seedlings is increased by the presence of ectotrophic mycorrhizas¹. Harley et al. ² have shown, however, that when labelled phosphorus is supplied to excised roots of beech the presence of a mycorrhizal sheath presents a partial barrier to phosphorus uptake by the tissues of the root. This communication reports the result of an experiment in which phosphorus-32 was used to indicate how far the mycorrhizal habit influences the uptake of phosphorus by intact plants of Nothofagus menziesii (mycorrhizas ectotrophic, typical of the Fagaceae) and Pinus radiata. The presence of mycorrhizas had no apparent effect on the rate of growth of these two species under the conditions employed in the experiment.