Dissertation/Thesis Abstract

A RADseq Phylogeny of Barleria (Acanthaceae) Resolves Fine-scale Relationships
by Comito, Robert P., M.S., California State University, Long Beach, 2019, 88; 13902604
Abstract (Summary)

Barleria is a genus of approximately 300 species in the family Acanthaceae. Species of Barleria are widely distributed across the paleotropics, with variable habits and vegetative and reproductive morphologies. Barleria are typically herbs or shrubs, and can be recognized by a combination of characters: four sepals in the calyx, a small inner pair and larger outer pair; double cystoliths in epidermal cells; an abaxial pair of stamens with filaments that twist through 180° and cross just distal to the synstapetal zone; and globose, honeycombed pollen. Historically, natural groupings in the genus have proven elusive because so many morphological characters that are consistent in other Acanthaceae genera are highly variable in Barleria. Previous morphological studies classified species in the genus into two subgenera and seven sections. More recently, a molecular study that sampled 53 Barleria species for four chloroplast loci and the nuclear locus nrITS supported the subgenera and four of the seven recognized sections. The aim of this study was to estimate relationships in the genus through a phylogenetic analysis that samples 182 accessions representing 176 distinct taxa, including varieties and subspecies of 169 species from Barleria (56% of total species diversity of 300), representing all sections and the geographic range of the genus. Additionally, four outgroup species were sampled from closely related genera (Crabbea, Lepidagathis, and Whitfieldia) for a total of 186 accessions for 180 taxa. Single nucleotide polymorphism data were generated using libraries prepared in house for double-digest restriction-site associated DNA sequencing. Loci were assembled de novo in iPyrad and used to estimate a maximum likelihood phylogeny. The RADseq phylogeny corroborated the chloroplast and nrITS topology and resolved a polytomy in subg. Barleria that included the type species, B. cristata. The RADseq phylogeny also resolved fine-scale relationships within sections. Vegetative and reproductive morphological evolution in Barleria, sect. Prionitis was examined through ancestral state reconstructions. My results broadly inform our understanding of diversity and evolution in one of the largest genera of Acanthaceae.

Indexing (document details)
Advisor: Fisher, Amanda E.
Commitee: Brusslan, Judy, Darbyshire, Iain
School: California State University, Long Beach
Department: Biological Sciences
School Location: United States -- California
Source: MAI 81/3(E), Masters Abstracts International
Source Type: DISSERTATION
Subjects: Biology, Botany
Keywords: Acanthaceae, Barleria, Morphology, Phylogenetics, Phylogenomics, Systematics
Publication Number: 13902604
ISBN: 9781088336915
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