Sex, Diversity, and Differentiation Within and Between Populations of an Aquatic Hyphomycete
Anderson, Jennifer Lynn
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/87044
Description
Title
Sex, Diversity, and Differentiation Within and Between Populations of an Aquatic Hyphomycete
Author(s)
Anderson, Jennifer Lynn
Issue Date
2004
Doctoral Committee Chair(s)
Carol A. Shearer
Weidong Chen
Department of Study
Plant Biology
Discipline
Plant Biology
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Biology, Plant Physiology
Language
eng
Abstract
Aquatic hyphomycetes contribute to energy flow and nutrient spiraling in rivers by making energy and fixed carbon in autumn-shed leaves available to aquatic invertebrates. These fungi are haploid, predominantly or exclusively asexual, have restricted dispersal abilities, and experience yearly population bottlenecks as the amount of available substrate decreases in late summer; four factors that may limit the ability of populations of aquatic hyphomycetes to acquire and maintain genetic diversity. Tetracladium marchalianum is used in this study to answer three questions pertaining to the natural histories and evolutionary potential of these ecologically important fungi. (1) Is genetic recombination contributing to genotypic diversity of this fungus? (2) How is genotypic diversity distributed among populations of this fungus? (3) Is genotypic diversity changing over time as population size rises and falls seasonally? To answer these questions, polymorphic microsatellite and AFLP loci were identified for T. marchalianum and used to obtain multilocus haplotypes for use in population genetic analyses. Leaves from three sites on the Sangamon River (Illinois), three sites on the Middle Fork of the Vermilion River (Illinois), and one site on Konkapot Creek (Wisconsin) served as the sources of fungal cultures, each originating from a single asexually produced spore, allowing genotypic diversity and genetic differentiation to be assessed within each stream at different sites as well as between rivers from different watersheds. Collections were also made from one site on the Sangamon River repeatedly over two years, allowing analysis of genotypic diversity changes over time. Index of Association and Parsimony Tree Length Permutation Test analyses did not detect recombination in populations of T. marchalianum , providing evidence for clonality in this species. All Illinois sites, although spatially separated within rivers and between rivers in different watersheds, demonstrate no significant differentiation. Significant differentiation between populations was only observed between the most distant sites (Illinois vs. Wisconsin). Analyses of differentiation among collections from two years of collections on the Sangamon River do not indicate temporal population differentiation; therefore, if population bottlenecks are occurring annually, they are not dramatically altering the population genetics of this fungus.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
