Year of Award

2017

Document Type

Thesis

Degree Type

Master of Science (MS)

Degree Name

Organismal Biology, Ecology, and Evolution

Department or School/College

Division of Biological Sciences

Committee Chair

John McCutcheon

Commitee Members

Anna Sala, Scott Miller

Keywords

Antidea; Ascomycota; Aspicilia; cryptic diversity; Teuvoa; Montana.

Subject Categories

Biodiversity | Biology | Botany | Evolution | Molecular Genetics

Abstract

The lichen symbiosis is one of the oldest studied mutualisms; in fact, Frank and De Bary coined the term "symbiosis" while studying lichens (Frank, 1877; De Bary 1879). The widespread, stable association between the mycobiont and photobiont in lichens offers an ideal system for the study of co-evolution. The recent application of molecular data to lichens has begun to unveil the complexities involved in these associations (Upreti et al. 2015, Spribille et al. 2016). Lichenized fungi make up a huge fraction of fungal diversity (Nash 2008), yet very little is known of their genetic diversity. Fungal taxonomy is notoriously difficult using the standard “barcoding” genes, so the deep relationships between most lichens are poorly resolved (Schoch et al. 2012). Here I apply a combination of Sanger and next-generation sequencing technologies to the cosmopolitan lichen family Megasporaceae to generate a robust phylogenetic tree for the group. The genus Aspicilia is highly diverse, poorly collected, common across all continents, and lives on a wide range of substrates and environments (Nordin et al. 2010). Aspicilia is principally a genus of crustose lichens inhabiting rocks (saxicolous), although a few species are known to inhabit soil and wood. They are usually tightly attached to the substrate, with a few groups occasionally lifting off the substrate and becoming semi-fruticose (3-dimensional). Aspicilia is one of five genera in the recently resurrected family Megasporaceae (Nordin et al. 2010) and the most speciose in the family, with over 230 valid names. Phylogenetic analyses confirmed the monophyly of the family Megasporaceae. The new genera Antidea and Arctidea are described. The recently described Teuvoa is subsumed within an expanded Lobothallia. The genera Megaspora and the recently resurrected Aspiciliella are subsumed within Circinaria. This study supports the segregation of the Megasporaceae into seven genera, Antidea, Aspilidea, Lobothallia, Arctidea, Sagedia, Circinaria and Aspicilia, describes three new species, proposes nineteen new combinations, and provides a robust phylogeny for the group that will be used as a backbone for future studies in the family.

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© Copyright 2017 Tim B. Wheeler