INTERCONTINENTAL PHYLOGEOGRAPHY OF FUSARIUM SOLANI SPECIES COMPLEX ASSOCIATED WITH AN INVASIVE XYLOPHAGOUS CERAMBYCID
Open Access
- Author:
- Campbell, Alexander Michael
- Graduate Program:
- Molecular, Cellular and Integrative Biosciences
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- April 13, 2018
- Committee Members:
- Kelli Hoover, Thesis Advisor/Co-Advisor
David Geiser, Committee Member
Margarita López-Uribe, Committee Member - Keywords:
- Asian longhorned beetle
Anoplophora glabripennis
Fusarium solani
invasive species
phylogeny - Abstract:
- Investigating how gut symbiotic relationships change in the introduced range of invasive species may elucidate information about the role of evolutionary and environmental factors shaping these relationships. Fusarium solani species complex (FSSC) is a diverse group of ascomycetes that contains both plant and animal pathogens in addition to saprobes and symbionts. Genetic and transcriptomic evidence points to a symbiotic role for FSSC isolates in their relationship with Asian longhorned beetle, Anoplophora glabripennis, a tree-killing xylophage. However, how these relationships have changed as a result of the global invasion of the beetle has never been investigated. This study investigated the phylogeography of native, invasive and lab-reared populations of A. glabripennis and their FSSC associated isolates. Samples were collected from five sites in China, the U.S. and two lab-reared colonies. Spatial principal component analysis revealed lack of phylogeographic structure among beetle populations reflecting the recent history of invasion of this species in North America. Phylogenetic analysis revealed that native and invasive populations of FSSC symbionts were associated with three distinct species in a major clade of FSSC found in a variety of substrates, including woody plants and insects. On the contrary, lab-reared insects showed unique fungal associates compared to tree-feeding insects. Isolates of one undescribed species, FSSC 29, were localized to specific geographies. Our results suggest that FSSC associates are non-randomly distributed based on the geography and that rearing environment plays an important role determining the identity of these symbionts in their hosts.