Fungi associated with hair roots of Rhododendron lochiae (Ericaceae) in an Australian tropical cloud forest revealed by culturing and culture-independent molecular methods

The culturable fungal assemblage associated with hair roots of Rhododendron lochiae (Ericaceae) from a tropical cloud forest in Queensland, Australia was investigated using rDNA internal transcribed spacer (ITS) restriction fragment length polymorphisms (RFLPs) and sequence analysis, and the abilities of the fungi to form ericoid mycorrhizas were tested. DNA was further extracted directly from hair roots and partial fungal ITS products compared with those from the cultured isolate assemblage using denaturing gradient gel electrophoresis (DGGE). A range of ericoid mycorrhizal and non-mycorrhizal fungi was identified using both approaches, with ericoid mycorrhizal fungi found to be taxonomically similar to those associated with Ericaceae in temperate habitats worldwide. Both approaches identified several unique fungi and, although most of the abundant RFLP types identified in the cultured fungal assemblage were also present in DGGE profiles of DNA extracted directly from roots, one the most commonly isolated RFLP types, a putative Xylariaceae taxon, was absent. The data suggest that a combination of culturing and culture-independent approaches may be more efficacious than either method individually.