Abstract Detail



Systematics

Stettler, Jason [1].

Speak to me beardtongue: Phylogenetic analysis of the six Penstemon subgenera using whole chloroplast genome sequences.

The beardtongues (Penstemon Mitchell) are a genus of over 260 species of perennial forbs and sub-shrubs native to North America divided into six subgenera primarily based on floral characteristics. The genus is relatively young, with an estimated origin during the late Pliocene around 2.5 MYA. Although it has a recent geologic origin, it has undergone rapid diversification with species occupying all North American habitats including the Arctic Circle, the Central American, alpine meadows, arid deserts, and grasslands. Due to the rapid rate of diversification and speciation observed with this genus, many phylogenetic studies using individual or concatenated chloroplast gene sequences have failed to resolve polytomic clades of closely related species within subgenera. We sequenced the complete chloroplast genomes (plastomes) of representative species from each Penstemon subgenera using the Illumina Hi-Seq (2x250) platform, assembled, annotated, and analyzed the plastomes’ gene content, gene order and synteny, and Maximum Likelihood phylogenetic relationships among the Lamiales order. We also compared whole plastome phylogenies to the coding regions (matK and rbcL) and non-coding regions (trnaC-D and trnaT-L) that are commonly used in phylogenetic studies. We found that the whole plastome phylogenies within Penstemon genus and within the Lamiales order were different from single and concatenated coding regions and non-coding regions had different structures and most nodes had far less nodal support. The high nodal support at each node on the phylogenies produced with the whole plastomes suggests that greater accuracy in describing the hierarchal relationships among taxa to delineate species than with single or concatenated gene sequence phylogenies.


1 - Brigham Young University, Plant and Wildlife Sciences, 701 East University Parkway Drive, 4105 LSB, Provo, UT, 84602, United States

Keywords:
Penstemon
beardtongue
maximum likelihood
plastome
chloroplast genome
Phylogenetics
Lamiales.

Presentation Type: Oral Paper
Number:
Abstract ID:125
Candidate for Awards:George R. Cooley Award


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