This study will expand and refine a molecular method for identification of ectomycorrhizal fungi. The method is based on amplification of DNA with the polymerase chain reaction coupled with oligonucleotide hybridization assays of the resulting productd. The sensitivity of the method enables fungal symbionts from individual mycorrhizal rootlets to be identified to a variety of taxonomic levels (e.g., order to strain) and tree hosts to be identified simultaneously. This method will be used to examine several ecologically significant host-symbiont interactions; mycorrhizal parasitism, fungal symbiont sharing and host specificity and competitive interactions among selected species. These studies will provide the necessary foundation for later testing of theories of fungal succession and mycorrhizal community structure, phenomena that are highly significant in virtually all terrestrial habitats.
