Does the presence of arbuscular mycorrhizal fungi influence growth and nutrient uptake of a wild-type tomato cultivar and a mycorrhiza-defective mutant, cultivated with roots sharing the same soil volume?

Authors

  • Elke Neumann,

    Corresponding author
    1. Institute of Plant Nutrition (330), Hohenheim University, 70593 Stuttgart, Germany;
    Search for more papers by this author
  • Eckhard George

    1. Soil Science and Plant Nutrition, School of Earth and Geographical Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia;
    2. Permanent address: Physiology of Plant Nutrition, Institute of Crop Sciences, Humboldt University Berlin and Institute of Vegetable and Ornamental Crops (IGZ), 14979 Grossbeeren, Germany
    Search for more papers by this author

Author for correspondence: Elke Neumann Tel: +49 (0)711 459 3504 Fax: +49 (0)711 459 3295 Email: eneumann@uni-hohenheim.de

Summary

  • • We investigated the growth and nutrient uptake of the Lycopersicon esculentum symbiosis mycorrhiza-defective plant mutant rmc, challenged with arbuscular mycorrhiza (AM) fungal propagules, in the presence or absence of roots of the commercial wild-type tomato cv. Golden Queen (GQ).
  • • Two plants shared the middle (combi) compartment of a horizontal three-compartment split-root pot with one part of their root system; the other part was grown separately in an outer (solo) pot. Combinations of rmc and GQ plants were grown together in soil that was either mycorrhiza-free (–M) or prepared with AM fungal inoculum (+M).
  • • Surface colonization of rmc roots was strongly increased in the presence of (+M) GQ roots. AM fungal inoculation increased phosphorus uptake of GQ plants, but decreased growth and P uptake of rmc plants. Growth and P uptake of (+M) GQ plants were reduced when plants were grown in combination with rmc rather than another GQ plant.
  • • AM fungi in the (combi) compartment may have preferentially formed hyphae spreading infection rather than functioning in P uptake in (+M) GQ plants grown in combination with rmc. Surface colonization of (+M) rmc roots, in the presence of GQ roots, was probably established at the expense of carbohydrates from associated GQ plants. Possible reasons for a decreased P uptake of rmc plants in response to AM fungal inoculation are proposed.

Ancillary