Title: Sympatric bromeliad species (Pitcairnia spp.) facilitate tests of mechanisms involved in species cohesion and reproductive isolation in Neotropical inselbergs
Abstract: Molecular EcologyVolume 20, Issue 15 p. 3185-3201 Sympatric bromeliad species (Pitcairnia spp.) facilitate tests of mechanisms involved in species cohesion and reproductive isolation in Neotropical inselbergs C. PALMA-SILVA, C. PALMA-SILVA Jodrell Laboratory, Royal Botanic Gardens Kew, Richmond, Surrey TW9 3DS, UK Instituto de Botânica, 04301-902 São Paulo, BrazilSearch for more papers by this authorT. WENDT, T. WENDT Departamento de Botânica, CCS/IB/UFRJ, 21941-590 Rio de Janeiro, RJ, BrazilSearch for more papers by this authorF. PINHEIRO, F. PINHEIRO Instituto de Botânica, 04301-902 São Paulo, BrazilSearch for more papers by this authorT. BARBARÁ, T. BARBARÁ Jodrell Laboratory, Royal Botanic Gardens Kew, Richmond, Surrey TW9 3DS, UK Unit of Ecology and Evolution, Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, SwitzerlandSearch for more papers by this authorMICHAEL F. FAY, MICHAEL F. FAY Jodrell Laboratory, Royal Botanic Gardens Kew, Richmond, Surrey TW9 3DS, UKSearch for more papers by this authorS. COZZOLINO, S. COZZOLINO Dipartimento di Biologia Strutturale e Funzionale, Università degli Studi di Napoli Federico II, 80100 Napoli, ItalySearch for more papers by this authorC. LEXER, C. LEXER Unit of Ecology and Evolution, Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, SwitzerlandSearch for more papers by this author C. PALMA-SILVA, C. PALMA-SILVA Jodrell Laboratory, Royal Botanic Gardens Kew, Richmond, Surrey TW9 3DS, UK Instituto de Botânica, 04301-902 São Paulo, BrazilSearch for more papers by this authorT. WENDT, T. WENDT Departamento de Botânica, CCS/IB/UFRJ, 21941-590 Rio de Janeiro, RJ, BrazilSearch for more papers by this authorF. PINHEIRO, F. PINHEIRO Instituto de Botânica, 04301-902 São Paulo, BrazilSearch for more papers by this authorT. BARBARÁ, T. BARBARÁ Jodrell Laboratory, Royal Botanic Gardens Kew, Richmond, Surrey TW9 3DS, UK Unit of Ecology and Evolution, Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, SwitzerlandSearch for more papers by this authorMICHAEL F. FAY, MICHAEL F. FAY Jodrell Laboratory, Royal Botanic Gardens Kew, Richmond, Surrey TW9 3DS, UKSearch for more papers by this authorS. COZZOLINO, S. COZZOLINO Dipartimento di Biologia Strutturale e Funzionale, Università degli Studi di Napoli Federico II, 80100 Napoli, ItalySearch for more papers by this authorC. LEXER, C. LEXER Unit of Ecology and Evolution, Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, SwitzerlandSearch for more papers by this author First published: 15 June 2011 https://doi.org/10.1111/j.1365-294X.2011.05143.xCitations: 128 Clarisse Palma-Silva, Fax: +55 11 50733678; E-mail: [email protected] Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract The roles of intra- and interspecific gene flow in speciation and species evolution are topics of great current interest in molecular ecology and evolutionary biology. Recent modelling studies call for new empirical data to test hypotheses arising from the recent shift from a 'whole-genome reproductive isolation' view to a 'genic' view of species and speciation. Particularly scarce (and thus of particular interest) are molecular genetic data on recently radiated, naturally hybridizing species in strongly structured and species-rich environments. Here, we studied four sympatric plant species (Pitcairnia spp.; Bromeliaceae) adapted to Neotropical inselbergs (isolated outcrops resembling habitat 'islands' in tropical rainforests) using nuclear and plastid DNA. Patterns of plastid DNA haplotype sharing and nuclear genomic admixture suggest the presence of both, incomplete lineage sorting and interspecific gene flow over extended periods of time. Integrity and cohesion of inselberg species of Pitcairnia are maintained despite introgression and in the face of extremely low within-species migration rates (Nem < 1 migrant per generation). Cross-evaluation of our genetic data against published pollination experiments indicate that species integrity is maintained by the simultaneous action of multiple prezygotic barriers, including flowering phenology, pollinator isolation and divergent mating systems. Postzygotic Bateson–Dobzhansky–Muller incompatibilities appear to contribute to isolation, as suggested by asymmetric introgression rates of single loci. Our results suggest that incomplete lineage sorting, hybridization and introgression form integral aspects of adaptive radiation in Neotropical inselberg 'archipelagos'. Inselbergs with multiple closely related co-occurring species should be of special interest to students of speciation in mountain systems, and to ongoing conservation programmes in the Atlantic Rainforest biodiversity hotspot. Citing Literature Supporting Information Table S1 Primer sequences and characteristics of plastid DNA microsatellite loci in Pitcairnia spp., including locus name, plastid DNA region, primer sequences, repeat type, allele size range, and no. of alleles. Table S2 Genetic variability at 15 microsatellite loci in P. staminea, P. albiflos, and their hybrids, including locus name, number of alleles (A), observed heterozygosity (HO), expected heterozygosity (HE), standardized measure of differentiation (G′ST), fixation index (FST), total inbreeding coefficient (FIT), and within-population inbreeding coefficient (FIS). Table S3 Analysis of Molecular Variance (amova) based on nuclear microsatellite data for P. staminea and P. albiflos for two different hierarchical models. (A) species level. (B) geographical level (inland vs. coastal inselbergs). Percentages of variation in parentheses refer to models in which hybrids were nested with P. albiflos. Table S4 Genetic divergence (FST; below diagonal) and gene flow (Nem; above diagonal) for pairs of populations of the inselberg bromeliads Pitcairnia albiflos and P. staminea and their hybrids. Nem = (1/FST − 1)/4. Table S5 Locus-specific, bidirectional introgression rates between Pitcairnia albiflos and P. staminea on PAO population. Fig. S1 Magnitude of ΔK from structure analysis as a function of K (mean ± SD over 10 replicates), calculated following the ΔK method proposed by Evanno et al. (2005), for Pitcairnia albiflos and P. staminea microsatellite data. Fig. S2 Posterior probabilities (q) of Pitcairnia albiflos and Pitcairnia staminea for the two hybrid zones analyzed with newhybrids. Filename Description MEC_5143_sm_FigureS1.pdf13.9 KB Supporting info item MEC_5143_sm_FigureS2.pdf51.3 KB Supporting info item MEC_5143_sm_TableS1-S5.docx162 KB Supporting info item Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. Volume20, Issue15August 2011Pages 3185-3201 RelatedInformation