The functional significance for the orchid Caladenia tentaculata of genetic and geographic variation in the mycorrhizal fungus Sebacina vermifera s. lat. complex

Abstract

To investigate the influence of provenance of mycorrhizal fungi on functional diversity in orchids, six isolates of two taxa in the Sebacina vermifera complex, were sourced from Victorian Caladenia tentaculata populations. Germination of orchid seeds with isolates from their own and other populations in vitro and utilisation of a range of carbon and nitrogen substrates for growth in culture were tested.There was considerable inter-and intrataxon variation in seed germination abilities but no evidence of a 'home site' advantage for fungal isolates. All isolates utilised the carbon compounds carboxymethyl cellulose and pectin, and inorganic nitrogen in the form of NH 4+ but not NO 3-, as their..