Complete Citation: Dearnaley, John and Le Brocque, Andrew F. (2006). Molecular identification of the primary root fungal endophytes of Dipodium hamiltonianum

We have identified the primary root fungal endophytes of Dipodium hamiltonianum F.M. Bailey, a species of orchid endangered in Victoria and uncommon in New South Wales and Queensland. Genomic DNA was extracted from whole colonised root portions from four orchid individuals and PCR amplified with ITS1F and ITS4 primers. Cloning and sequencing of the main amplicons produced from the PCR analysis revealed that the primary root fungal endophytes were Gymnomyces and Russula spp., both members of the Russulaceae. The implications of this finding are discussed in terms of conservation of the orchid species. Introduction Dipodium hamiltonianum or yellow hyacinth orchid is a large terrestrial orchid species found in woodlands throughout eastern Australia (Jones 1988; Riley and Banks 2002). The plant grows to almost 1 m, and is distinct from other Dipodium species in that its leafless pale stems bear up to 35 red-purple spotted yellow flowers (Fig. 1; Bishop 1996). The distribution range of D. hamiltonianum includes Victoria, where its status is endangered (Conservation and Natural Resources 1994), to New South Wales and Queensland; where it is uncommon (Riley and Banks 2002). Threats to the species appear