title: Gene discordance in phylogenomics of recent plant radiations, an example from Hawaiian Cyrtandra (Gesneriaceae).
abstract: Resolving species relationships within recent radiations requires analysis at the interface of phylogenetics and population genetics, where coalescence and hybridization may confound our understanding of relationships. We developed 18 new primer pairs for nuclear loci in Cyrtandra (Gesneriaceae), one of the largest plant radiations in the Pacific Islands, and tested the concordance of 14 loci in establishing the phylogenetic relationships of a small number of Hawaiian species. Four genes yielded tree topologies conflicting with the primary concordance tree, suggesting plastid capture and horizontal transfer via hybridization. Combining all concordant genes yielded a tree with stronger support and a different topology from the total-evidence tree. We conclude that a small number of genes may be insufficient for accurate reconstruction of the phylogenetic relationships among closely related species. Further, the combination of genes for phylogenetic analysis without preliminary concordance tests can yield an erroneous tree topology. It seems that the number of genes needed for phylogenetic analysis of closely related species is significantly greater than the small numbers commonly used, which fail to isolate coalescence, introgression and hybridization.
authors.affiliation: Tropical Conservation Biology and Environmental Science Program, University of Hawai'i at Hilo, 200 West Kawili Street, Hilo, HI 96720, USA. pillon@hawaii.edu
authors.forename: Yohan
authors.initials: Y
authors.lastname: Pillon
authors.forename: Jennifer B
authors.initials: JB
authors.lastname: Johansen
authors.forename: Tomoko
authors.initials: T
authors.lastname: Sakishima
authors.forename: Eric H
authors.initials: EH
authors.lastname: Roalson
authors.forename: Donald K
authors.initials: DK
authors.lastname: Price
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Stacy
mesh_terms: D001499:Bayes Theorem; D002467:Cell Nucleus / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D018744:DNA, Plant / Q000145:classification* / Q000235:genetics; D022761:Gene Transfer, Horizontal; D049810:Genetic Speciation; D006254:Hawaii; D006824:Hybridization, Genetic; D019684:Magnoliopsida / Q000145:classification* / Q000235:genetics; D010802:Phylogeny; D058974:Phylogeography; D063148:Plant Dispersal; D018087:Plastids / Q000235:genetics; D018401:Sample Size; D017422:Sequence Analysis, DNA
chemical_list: D017931:DNA Primers; D018744:DNA, Plant
keywords: Hawai‘i; Network; Next-generation sequencing; Nuclear genes; Phylogenomics; Ribosomal DNA