Document Type

Honors Thesis

Major

Ecology and Environmental Science

Advisor(s)

Seanna Annis, Joyce Longcore

Committee Members

Allison Gardner, Joshua Jones, William Livingston

Graduation Year

December 2020

Publication Date

Fall 12-2020

Abstract

Chytridiomycota is a phylum of microscopic aquatic fungi that form motile spores that typically have a single posterior flagellum, thus they require water to disperse (James et al., 2000). Chytridiomycota, collectively called chytrids, have round shapes with structures called rhizoids that absorb nutrients and anchor them to their substrate (Mueller et al., 2004). Chytrids are typically found in aquatic environments and soils since zoospores require water to germinate (James et al., 2000), but they also have been found in a number of unexpected environments. Chytrids are difficult to find because they are microscopic and have time-sensitive life cycles (Mueller et al., 2004). Isolation is difficult because chytrid species require specific nutrients for growth and grow less rapidly than filamentous fungi, yeasts and bacteria. Because chytrids have been found in many habitats and an extensive amount of research on their preferred habitat is lacking, my question was could chytrids be observed and isolated from tree bark samples. In this study bark samples and soil at the base of the trees were collected from red maple (Acer rubrum) and amur cork (Phellodendron amurense) in Pennsylvania, Sunkhaze wildlife refuge in Milford, Maine, and the University of Maine campus in Orono, Maine. A teaspoon of bark or soil was put in gross cultures to bait chytrids. Every sample contained chytrids, abundantly on spruce pollen grain baits and sparsely on onion skin bait. The Internal transcribed spacer (ITS) regions of the ribosomal gene cassette were amplified from extracted DNA for sequencing and will be used to identify the genera of chytrids collected and isolated from samples. The ITS regions amplify highly variable gene sequences that are used to identify fungi. More research is needed, but these findings support that Chytridiomycota can be found on tree bark.

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