Lexer et al. 2016 (Article) Alcantarea

Gene flow and diversification in a species complex of Alcantarea inselberg bromeliads

Author(s):—C Lexer, F. Marthaler, T. Barbará, M. de la Harpe, E. Bossolini, M. Paris, G. Martinelli & L.M. Versieux

Publication:—Botanical Journal of the Linnean Society 181: 505–520. With 6 figures. (2016) — DOI

Abstract:—Inselberg-adapted species of bromeliads (Bromeliaceae) have been suggested as model systems for understanding
the evolutionary genetics of species complexes and radiations in terrestrial, island-like environments. Bromeliads
are particularly suitable for addressing the potential roles of interspecific gene exchange during plant speciation
and radiation. We have studied populations of five narrowly endemic Alcantarea species adapted to highelevation
inselbergs of the Atlantic Rainforest of Brazil with nuclear and plastid DNA markers, estimated
outcrossing rates in the giant bromeliad A. imperialis using progeny arrays and carried out a pilot study on the
use of next generation sequencing-based genotyping in this group. Our results suggest widespread and
asymmetric interspecific gene flow in the studied species complex, which visibly affects patterns of genetic
diversity in the phenotypically variable mixed outcrosser A. imperialis. Our data support the hypothesis that
gene flow has contributed to the origin of phenotypic forms in the A. imperialis s.l. species complex. We discuss
potential conflicts between our neutral marker data and previous taxonomic work and suggest how these might
be resolved. We close with a brief outlook on the potential of genomic tools to uncover the hidden links between
genotypes, phenotypes and niches in bromeliads and other plant radiations

Keywords:—adaptive radiation – hybridization – microsatellites – outcrossing – plastid DNA – restriction site-associated DNA sequencing – speciation.