Abstract: The microstructure of mycorrhizal root of Rhododendron fortunei L. were observed with scanning electron microscope and fresh mount of hair root stained with trypan blue and resin section. Results showed that the hair roots consisted of one layer of epidermis cells and 1-2 layers cortical cells surrounding the stele; the hair roots did not form root hair and were covered with loose or compact fungal mantle; the presence of the mycorrhizal fungus in epidermal cells did not appear to disrupt the primary tissue structure of the root, except that mature epidermal contain ericoid mycorrhizal (ERM) hyphal coils; the fungal complex were mostly observed in epidermal cells and the cell wall of 90% epidermal cells with fungus were not obviously thickened; according to the morphological feature of the hyphae and hypha complex, at least two types of fungi appeared to form mycorrhizal coils in epidermal cells. One type was a thick mycelium fungus which formed tight coils, the other was a thin mycelium fungus formed loose coils.

Key words: Rhododendron fortunei L., ericoid mycorrhiza, morphology, anatomy