Abstract Detail



Systematics

Comito, Robert [1], Darbyshire, Iain [2], McDade, Lucinda [3], Fisher, Amanda [4].

A RADseq Phylogeny of Barleria (Acanthaceae) Resolves Fine-Scale Relationships .

Barleria is a genus of approximately 325 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 a combination of synapomorphies: 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 within 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 (52% of total species diversity of 325), representing all sections and the geographic range of the genus. Additionally, ten outgroup species were sampled from closely related genera (Andrographis, Crabbea, Justicia, Lepidagathis, Lophostachys, Neuracanthus, and Whitfieldia) for a total of 192 accessions for 186 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, leading to recognition of several new sub-sections. Vegetative and reproductive morphological evolution in one section of Barleria, sect. Prionitis, was examined through ancestral state reconstructions. Our results lead to the revision of the sectional and sub-sectional classification of Barleria and more broadly inform our understanding of diversity and evolution in one of the largest genera of Acanthaceae. 


1 - California State University, Long Beach, Biological Sciences, 1250 Bellflower Blvd, Long Beach, CA, 90840, United States
2 - Kew, Identification and Naming, TW9 3AE, Richmond, Surrey, UK
3 - Rancho Santa Botanic Garden, Rancho Santa Ana Botanic Garden, 1500 N College Ave, CLAREMONT, CA, 91711, United States
4 - California State University, Long Beach, Biological Sciences, Mail Stop 9502, 1250 Bellflower Blvd, Long Beach, CA, 90840, United States

Keywords:
Barleria
systematics
Acanthaceae
RADseq
ddRAdseq
Phylogenetics
Lamiales.

Presentation Type: Oral Paper
Number:
Abstract ID:904
Candidate for Awards:George R. Cooley Award


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