University of Hawai‘i at Hilo

Current Research Projects

Diversity and Dynamics of Fungal Community Structure in Native Hawaiian Forests across Elevational and Successional Gradients

Building upon previous work done on the Hawaiian Islands documenting the diversity of fleshy macrofungi using traditional sampling methods (i.e., collection of fruiting structures), this project is adding a molecular component through the collection of environmental isolates and construction of cloning libraries. Fungal DNA will be isolated from both soil and plant material, cloned, sequenced, and analyzed within a phylogenetic framework. The results of this project will provide a much broader picture of both the taxonomic and genetic fungal diversity present in native Hawaiian forests, including both macro- and microscopic taxa. Additionally, the span of this project across both spatial and temporal gradients will allow the investigation of not only changes in species composition and function, but also how such changes may play a role in fungal speciation and that of any associated plant species.

Molecular Systematics and Evolution of the Mycenoid Fungi (Euagarics, Basidiomycota)

This NSF funded project focuses on phylogenetic systematics in the mushroom genus Mycena s.l. and allied mycenoid fungi (Tricholomataceae, Euagarics), and is being conducted in the laboratory of Dr. Dennis E. Desjardin at San Francisco State University. Our goal is to sample nucleotide sequence data from three nuclear and two mitochondrial genes for approximately 300 tropical and temperate members of this group to infer their evolutionary relationships. With over 1880 species epithets published in Mycena alone, the mycenoid fungi represent one of the most diverse groups of saprotrophic mushrooms in the world. Members of the group play major roles in litter decomposition, nutrient recycling and retention, soil genesis, litter binding, and as a food source for innumerable animals. Within the group, morphological diversity is remarkably high. Body forms range from stipitate-lamellate or pleurotoid forms to reduced-cyphelloid forms with smooth hymenophores and tiny cupulate basidiomes, and even poroid forms. To date no comprehensive classification system exists for the mycenoid fungi, and very little is known about the natural relationships and phylogenetic placement of the over 60 described genera within the euagarics.

The objectives of this project are: 1.) Construct a robust multigene phylogeny of the mycenoid fungi. In conjunction with morphological, ecological, and biogeographic information, the phylogeneny will be used to resolve the natural relationships between the core clade of mycenoid fungi and other mycenoid genera of the Tricholomataceae, and to resolve familial, generic, and sectional boundaries within the mycenoid fungi. 2.) Use the phylogeny to infer patterns of character evolution within the mycenoid fungi, including those pertinent to infrageneric classifications, as well as fruiting body morphologies and the presence of bioluminescence. 3.) Use the phylogeny to examine biogeography and origins of diversity within in the mycenoid fungi. Taxon sampling for this project will include representatives of all allied genera and all infrageneric taxa in Mycena sensu lato. The genomic regions targeted for phylogenetic reconstruction include portions of the genes encoding for the nuclear large ribosomal subunit, the second largest subunit of RNA polymerase, translation elongation factor-1α, the mitochondrial protein atp6, and the mitochondrial small ribosomal subunit.