Monographic Studies of Southeast Asian Saprotrophic Agaricales Project Summary

We propose to conduct monographic studies of the marasmioid and mycenoid agarics (Fungi, Basidiomycota, Agaricales, Tricholomataceae) from mycologically underexplored regions of Southeast Asia. These studies will be based on analyses of type specimens, other herbarium specimens, and new collections. Phylogenetic hypotheses will be inferred from molecular sequence data to aid in redefining the taxonomic boundaries of Marasmius, Marasmiellus, Mycena and segregate genera that belong to the marasmioid and mycenoid agaric lineages.
Marasmius (>1600 epithets), Marasmiellus (>300 epithets), and Mycena (>1200 epithets), are the most diverse genera of saprotrophic mushrooms known in the world. Nearly all species are saprotrophic, serving important ecological roles in litter decomposition, nutrient recycling and retention, soil genesis, litter binding with its concommitant inhibition of erosion, and as food sources for innumerable animals. A few species are parasitic on economically important food crops, and several species form biomedically important antibiotics. Many species are substrate-specific which accounts for some of the high diversity seen in tropical forests. Biotic surveys of Agaricales conducted by the PI in the Hawaiian Islands (1993-1998) and in Indonesia (1997-present) indicate that the most speciose and most commonly encountered genera of tropical saprotrophic agarics are Marasmius, Marasmiellus and Mycena. Approximately 25% of all mushroom species and 33% of all mushroom populations encountered belong to these three genera, and over one third of all specimens encountered in Southeast Asian tropics are apparently unknown to science! Moreover, no phylogenetic hypotheses have been published on this group of fungi, so the taxonomic boundaries of supraspecific taxa and the relationships among them remain elusive. Preliminary phylogenetic hypotheses based on molecular data sets suggest that many marasmioid and mycenoid genera as currently delimited are not monophyletic. These observations are the primary reason why the PI has chosen to focus on these taxa for the proposed project. Conducting the biotic surveys indicated above have revealed the difficulty inherent in accurately naming agarics collected from underexplored tropical habitats. Although it is not difficult to collect, describe, and delimit the taxa encountered, because of the lack of monographic treatments of marasmioid and mycenoid agarics, accurate determination to species is nearly impossible. Monographic studies are imperative in order to build a taxonomic foundation to support biodiversity studies and to provide raw materials for phylogenetic analyses.
It is unfortunate that so few taxonomists currently study marasmioid and mycenoid agarics, a group that is known for its high diversity, high abundance, and paucity of taxonomic data. One of the most significant contributions we can make to the world systematics community is to train foreign students in contemporary techniques and analyses so that they can continue systematics and diversity studies in their home countries after the funded projects reach completion. It is also fundamentally important to begin intensive systematics training at the undergraduate and Master’s levels. A central component of the proposed project is to train Southeast Asian and US students in agaric systematics. A total of four graduate and several undergraduate students will participate in the project, conducting monographic and phylogenetic treatments of marasmioid and mycenoid fungi. Computerization is a hallmark of all aspects of the research, including specimen databasing, taxonomic and phylogenetic analyses, nomenclature and bibliographic databasing.
End products of the proposed project include the following: Descriptions of new species, type studies, and regional monographs of selected genera of marasmioid and mycenoid fungi will be published in refereed journals and in electronic format; a web page will be constructed detailing all aspects of the project; descriptive data, photographs, distribution records, keys, and phylogenetic hypotheses will be placed on-line; a database of all known epithets in Marasmius, Marasmiellus and Mycena with pertinent nomenclatural data will be available on-line; an accession-based specimen database will be available on-line; hundreds of new specimens will be deposited in SFSU; nLSU-rDNA, 5.8S-rDNA and ITS sequences of several hundred species of marasmioid and mycenoid fungi will be deposited in GenBank; four students will earn graduate degrees in fungal systematics; collaborations with colleagues in Southeast Asia will build lifelong partnerships that enhance taxonomic expertise in scientifically underdeveloped countries.