• arbuscular mycorrhizal (AM) fungi;
  • carbon sink;
  • colonization levels;
  • barley (Hordeum vulgare);
  • sugar maple (Acer saccharum);
  • Glomus intraradices;
  • Glomus mosseae;
  • Gigaspora rosea


  • •  
    Root carbon (C) partitioning in two host plant species colonized by one of three arbuscular mycorrhizal (AM) fungal species was investigated.
  • •  
    Split-root systems of barley (Hordeum vulgare) and sugar maple (Acer saccharum) were inoculated on one side with one of three AM fungi. Leaves were labelled with 14CO2 3 wk after inoculation. Plants were harvested 24 h later and the root systems from the mycorrhizal (M) and nonmycorrhizal (NM) sides were analysed separately for 14C.
  • •  
    Partitioning of 14C between M and NM sides varied depending on the fungal and host plant species used. Gigaspora rosea showed a strong C-sink capacity with both plant species, Glomus intraradices showed a strong C-sink capacity with barley, and Glomus mosseae did not affect 14C partitioning. The C-sink strength of the M barley roots inoculated with G. rosea or G. intraradices was linearly correlated with the degree of colonization.
  • •  
    The use of three AM fungal and two plant species allowed us to conclude that C-sink strength of AM fungi depends on both partners involved in the symbiosis.