The fungal endophytes of erythrorchis cassythoides - is this orchid saprophytic or parasitic?

Abstract

[Abstract]: Erythrorchis cassythoides is a common climbing orchid in eatern Australia. The plant lacks chlorophyll and typically is rooted at the base of mature trees suggesting the orchid receives its carbon supply via root fungi fromeither rotting vegetation or indirectly from living tree roots. We have analysed the fingal DNA within the roots of the orchid using ITS-PCR analysis, cloning and molecular sequencing to gain insight into the mode of nutrition of this orchid. fungal ITS rDNA sequences were successfully amplified and cloned from roots of three orchid plants occurring at different localities in SE Queensland. Comparison of these sequences with ITS rDNA in GenBank revealed that the fungal community of E.cassythoides roots consists of a saprotrophic homobasidiomycete and ectomycorrhizal fungal species thus suggesting that the orchid is potentially capable of both saprophytic and parasitic modes of nutrition.