Project Summary
The ‘true truffles’ are ascomycete fungi belonging to the genus Tuber and are distributed throughout the northern hemisphere. Species in the genus Tuber (Fungi, Ascomycota, Pezizales) produce underground fruits (truffles) that are widely sought as edible fungi. Tuber species form obligate ectomycorrhizal symbiosis with roots of many species of gymnosperm and angiosperm trees and shrubs, and are therefore an important component to the health and nutrition of forest ecosystems. Taxonomic studies of truffles rely heavily on the study of field-collected specimens, although in recent years a growing number of species are also becoming known through molecular-based studies of ectomycorrhizal fungal communities and environmental samples.
The goal of this project is to develop molecular-based systematics for the genus Tuber in order to establish links between taxonomic and ecological data and to develop descriptions and identification keys for all known taxa. This will be the first global analysis of evolutionary history of the genus Tuber. Emphasis is placed upon the study of truffle diversity in North America, which harbors much of the known species diversity in Tuber. Collection expeditions are planned to fill in gaps across the geographic range of this genus, with emphasis on eastern USA and Mexico.
The four main aims of this research are:
1. To establish an authoritative phylogenetic classification system for Tuber species based on multiple gene regions and morphological characters.
2. To define morphological and phylogeographic groupings within species complexes and widely distributed taxa (e.g. T. rufum complex, T. maculatum complex).
3. To integrate and assign unidentified Tuber collections from major herbaria as well as environmental samples (mycorrhiza and soil samples) into a phylogenetic classification system.
4. To disseminate results over the Internet by integrating taxonomic data of North American taxa with existing web-based descriptions.