The Structure and Fungal Associates of Mycorrhizas inLeucopogon parviflorus(Andr.) Lindl.

Mycorrhizal root systems of Leucopogon parviflorus (Andr.) Lindl. were collected from wild populations at three sites on the coast of New South Wales, Australia and examined by light and electron microscopy. The structure of the hair roots is typical of the family, there being an epidermal layer in which ericoid mycorrhizas are formed, two cortical layers (an exodermis and endodermis) and a very small stele. The colour, size and coil structure of the fungal symbionts indicate that there were at least two different fungi that consistently formed ericoid mycorrhizal structures at these sites. Transmission electron microscopy of the endophytes showed only ascomycete fungi. Plants from two of the populations were used for fungal isolations. Fungi were isolated by incubating surface sterilized hair-root pieces in a solution of bovine serum albumin with penicillin and streptomycin. Twenty-one different culture types were obtained, four of which were common to both sites. Two of the common culture types were dark, sterile, slow-growing cultures similar to the ericoid endophyte Hymenoscyphus ericae (Read) Korf & Kernan.