Fungi are among the most diverse groups of organisms on Earth, and they play many essential roles in the function, maintenance, and evolution of terrestrial ecosystems. Yet, they remain poorly studied. This project is concerned with taxonomy and systematics in the mushroom genus Mycena and allied genera, together referred to as the mycenoid fungi. With over 2000 named species distributed in about 60 described genera, the mycenoid fungi represent one of the most diverse groups of mushrooms in the world, with high taxonomic diversity in tropical regions. To date, no comprehensive classification system exists for these fungi, and their evolutionary relationships (genealogical or phylogenetic relationships) are still largely unknown. This lack of phylogenetic information hampers inferences about species distribution, origin, and dispersal (biogeography). It also prevents detailed studies about the evolution of fungal morphology and biochemistry with respect to ecology and environmental constraints, such as the reversal between gilled, poroid, and reduced forms, or the significance of fungal bioluminescence in nature. In this project, the investigators propose to construct a robust phylogeny for mycenoid fungi by sampling and analyzing nucleotide sequence data from three nuclear and two mitochondrial genes for approximately 300 tropical and temperate species, either already in hand or to be collected from the field. Mycenoid fungi are biologically significant for they are among the most widespread and abundant mushrooms in forest ecosystems worldwide. Most members of the group are litter decomposers, thus they play major roles in carbon cycling, turnover of soil nutrients, soil genesis, and the reduction of erosion via litter binding. A few species have been reported to be plant pathogens on economically important crops such as coffee or cacao, and others as symbionts with orchid roots. Also, because they are abundant, these fungi serve as a major food source for innumerable animals thereby playing a central role in the food web. The thorough understanding of the evolutionary history and biogeographic distribution patterns of mycenoid fungi that this study will provide will allow investigators to gain additional insights on the processes that contribute to the generation and maintenance of biological diversity. This has clear implications when making decisions regarding conservation and land management policy, and also for better understanding and monitoring the spread or shrinkage of native and invasive species. Results from this research will also provide novel data for further investigation on the role of fungi in the function of forest ecosystems. This project is complementary to and supportive of other ongoing NSF-funded projects, including a PEET grant to Dr Dennis Desjardin at San Francisco State University that aims at training young fungal taxonomists for continued enhancement of systematic biology, and to the Assembling the Fungal Tree of Life initiative. This project will support a postdoctoral associate, several undergraduate students, and one Asian PhD candidate at Chiang Mai University in Thailand.
