HARTIG NET STRUCTURE OF ECTOMYCORRHIZAE SYNTHESIZED BETWEEN LACCARIA BICOLOR (TRICHOLOMATACEAE) AND TWO HOSTS: BETULA ALLEGHANIENSIS (BETULACEAE) AND PINUS RESINOSA (PINACEAE)

Hartig net structure and ontogeny were compared in ectomycorrhizae synthesized between the broad host range fungus, Laccaria bicolor and two hosts, Betula alleghaniensis and Pinus resinosa. In B. alleghaniensis, the Hartig net was present in the epidermis of the three ectomycorrhizal types formed, fast-growing first-order laterals with proximal colonization, clavate second-order laterals, and nonclavate second-order laterals. Root hair-fungus interactions occurred in this association. In P. resinosa, the Hartig net developed in epidermal and cortical cell layers of monopodial and dichotomously branched first-order laterals. Short monopodial laterals exhibited a mantle only. Fungal hyphae in the Hartig net exhibited a complex labyrinthine mode of growth in ectomycorrhizae of both tree species.