ULTRASTRUCTURAL ASPECTS OF ENDOMYCORRHIZA IN THE ERICACEAE .1. NATURALLY INFECTED HAIR ROOTS OF CALLUNA-VULGARIS L HULL

The ultrastructural organization of endomycorrhizal hair roots of Calluna vulgaris has been studied in naturally infected plants by scanning and electron microscopy. Heavy fungal infection is present in, and limited to, cells of the root cortex. All intracellular hyphae have simple septa and associated Woronin bodies, characteristic of ascomycetous fungi. Penetrating hyphae are surrounded by a layer of inner host wall material. The host plasmalemma invaginates to surround the individual intracellular hyphae and it is separated from them by an interfacial matrix of varying thickness. No evidence of lysis or digestion of the intracellular hyphae by the host plant has been observed. Copyright © 1979, Wiley Blackwell. All rights reserved