Electronic Theses and Dissertations Archive

Date

2026

Document Type

Thesis

Degree Name

Master of Science

Department

Biology

Committee Chair

Shawn Brown

Committee Member

Jennifer Mandel

Committee Member

Stacy Byrd

Abstract

White oak (Quercus alba L.) reforestation relies on nursery-grown seedlings, yet the microbial processes influencing seedling quality and disease risk remain poorly understood. Integrating nursery fungal community ecology with pathogen genomics is essential to evaluate belowground dynamics relevant to artificial regeneration. Using ITS2 metabarcoding of 145 soil samples from a commercial Tennessee nursery, I compared fungal communities across one-year-old fumigated (1-0), two-year-old fumigated (2-0), and two-year-old unfumigated (2-0) nursery beds. Fungal richness and community composition differed among beds. Seedling age was associated with increased ectomycorrhizal abundance and higher relative abundances of putative plant pathogens, while fumigation reduced fungal richness and community variability, producing more consistent ectomycorrhizal-to-pathogen ratios. To investigate a key white oak pathogen, 32 U.S. isolates of Phytophthora cinnamomi were genome sequenced, expanding global resources fourfold. Comparative analyses revealed substantial functional variation and signatures of local adaptation. Together, these results improve understanding of microbial drivers of white oak regeneration.

Comments

Data is provided by the student.”

Library Comment

Dissertation or thesis originally submitted to ProQuest/Clarivate.

Notes

Open Access

Download

Share

COinS
 

Archival Statement

This item was created or digitized prior to April 24, 2026, or is a reproduction of legacy media created before that date. It is preserved in its original, unmodified state specifically for research, reference, or historical recordkeeping. This material is part of a digital archival collection and is not utilized for current University instruction, programs, or active public communication. In accordance with the ADA Title II Final Rule, the University Libraries provides accessible versions of archival materials upon request. To request an accommodation for this item, please submit an accessibility request form.