Diversity of mycobionts of Pisonia Grandis on coral cays
in the Great Barrier Reef
S. M. Chambers, C. J. Hitchcock, J. W. G. Cairney
Mycorrhiza Research Group, University of Western Sydney, Australia.
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An isolate of the Pisonia
grandis mycobiont from Heron Island, Great Barrier Reef, Australia, was
obtained in a previous study. This isolate was identified (using rRNA ITS sequencing) as a
basidiomycete belonging to the Thelephoraceae, probably a Tomentella or related
species, and was thought to be the sole mycobiont of P. grandis. In the present
study, rRNA ITS-RFLPs and sequencing of the ITS region were used to determine the identity
of mycobionts from P. grandis on other coral cays in the Capricornia bunker group.
Mycorrhizal roots were collected along transects on six cays including Heron Island. DNA
was isolated and subjected to rRNA ITS-RFLP analysis and ITS sequences were obtained for
selected samples. ITS-RFLP analysis identified a single fungal RFLP type to be present
across all six coral cays. This RFLP type was different to the mycobiont originally
isolated from Heron Island. The mycobiont was identified using sequence analysis as
belonging to the Thelephoraceae, with > 79% sequence identity to the previously
isolated mycobiont. The results will be
discussed in relation to the ecology of P. grandis on coral cays.