FUNGAL DIVERSITY

Biogeography

    We are using multilocus molecular methods to assess the diversity, origins and historical dispersal of selected Alaskan and arctic fungi. President's IPY Postdoc József Geml is taking the lead in this area through continued studies of Amanita muscaria and Agaricus as well as new projects on Boletus, Cortinarius, Russula, Flavocentaria and other taxa.  This work is in collaboration with Prof. Gary Laursen.  Graduate student John Haight is studying the biogeography of Fomitopsis pinicola in Alaska and elsewhere. 

 Community Structure

    We have undertaken a large-scale clone library sequencing project to characterize the composition of fungal communities in boreal forest soil, with sampling focused on the Bonanza Creek Long Term Ecological Research site in Interior Alaska.  To date we have sequenced roughly 100,000 clones from about 40 libraries constructed from over 2500 soil cores.  The project is titled Metagenomics of Boreal Forest Fungi - Linking Diversity with Function and was supported by the NSF-USDA Microbial Genome Sequencing Program.  It is a collaboration with the MIT-Broad Genome Sequencing Center.  Please see our Metagenomics site for more information.

 Adaptation to Cold

   We have recently been funded by NSF OPP for an IPY project titled "A Community Genomics Investigation of Fungal Adapation to Cold."  In this study, we will carry out clone library construction and sequencing of   both DNA and RNA pools extracted from soil samples collected along a latitudinal gradient, in summer versus winter, and in snow addition and exclusion manipulation plots. A major goal is to determine which species and guilds of fungi are most active under the snow pack, and are therefore most likely to contribute to the significant winter CO2 flux seen in high latitude systems.

PLANT-MICROBE INTERACTIONS

 Evolution of mycorrhizal specificity in orchids

   PhD student Sarah Hopkins is working on the evolution of specificity to mycorrhizal fungi in the non-photosynthetic orchid Corallorhiza maculata.  Our goal is to clarify the genetic underpinnings of specificity in sympatric, genetically divergent variants within this orchid species using microsatellite markers.  We are also testing whether the specificity demonstrated by some orchid genotypes is consistent across the entire geographic range of the orchid, and are attempting to reconstruct the migrational and population histories of these genetic lineages using both microsatellites and DNA sequences from multiple nuclear and chloroplast loci.

  Another orchid project is a collaboration with Melissa McCormick and Dennis Whigham at the Smithsonian Environmental Research Center.  This project is characterizing the substrate preferences and spatial distributions of the specific fungal symbionts of the orchids Tipularia discolor, Goodyera repens, Liparis lilifolia and Corallorhiza odontorhiza.  By combining molecular tracking of the fungi outside of the orchid with planting of orchid seeds, we will be able to test the extent to which fungal distribution limits the recruitment and distribution of orchids.  The UAF component of this project involves design of PCR primers for ribosomal regions and microsatellites in selected orchid fungi, primarily species of Tulasnella.

 Partner choice in alder-Frankia interactions

   The nitrogen fixation symbiosis between various Alnus species and actinorhizal bacteria in the genus Frankia is responsible for much of the nitrogen input to forest and shrubby tundra ecosystems in Alaska.  We have developed PCR methods to discriminate among strains of Frankia and have recently been funded to examine the degree to which alder choses optimal Frankia as well as ectomycorrhizal fungal symbionts depending on resource availability in the environment.  Roger Ruess is the PI of this project;  Knut Kielland is a Co-PI, and Mike Anderson and Jack McFarland are graduate students on the project.