J Syst Evol ›› 2017, Vol. 55 ›› Issue (4): 385-404.DOI: 10.1111/jse.12269

• Research Articles • Previous Articles     Next Articles

Increasing phylogenetic support for explosively radiating taxa: The promise of high-throughput sequencing for Oxytropis (Fabaceae)

Robabeh Shahi Shavvon1,2, Shahrokh Kazempour Osaloo1*, Ali Asghar Maassoumii3, Farideh Moharrek1, Seher Karaman Erkul4, Alan R. Lemmon5, Emily Moriarty Lemmon6, Ingo Michalak2, Alexandra N. Muellner-Riehl2,7*, and Adrien Favre2   

  1. 1Main address: Department of Plant Biology, Faculty of Biological Sciences, Tarbiat Modares University, 14115-154 Tehran, Iran
    2Department of Molecular Evolution and Plant Systematics & Herbarium (LZ), Institute of Biology, Leipzig University, 04103 Leipzig, Germany
    3Department of Botany, Research Institute of Forests and Rangelands, 13185-116 Tehran, Iran
    4Department of Biology, Faculty of Arts and Sciences, Aksaray University, 68100 Aksaray, Turkey
    5Department of Scientific Computing, Florida State University, Dirac Science Library, Tallahassee, FL 32306-4102, USA
    6Department of Biological Science, Florida State University, Tallahassee, FL 32306–4295, USA
    7German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig, 04103 Leipzig, Germany
  • Received:2017-03-26 Published:2017-07-24

Abstract: The origin and evolution of alpine biota are not yet fully understood, particularly in the vast Asian mountain regions. In addition, in these regions, most studies have concentrated on taxa occurring in areas benefitting from relatively generous rainfall from the summer monsoon. In this study, we collected a large number of Oxytropisspecies throughout their distribution range, and investigated the taxonomy and evolution of this diverse legume genus, which also occurs in mountainous areas prone to drought. Using nuclear (ITS) and plastid (trnL-F) markers, we reconstructed phylogenetic relationships within Oxytropis, conducting maximum parsimony, fasttree-like, maximum likelihood, Bayesian, and BEAST analyses. We also used Anchored Hybrid Enrichment (AHE) to test the power of this method to resolve relationships among a small subset of Oxytropis species. For AHE, we sampled eight species and obtained 527 low-copy and orthologous nuclear loci. We show that the taxonomy of this genus that radiated explosively in Asian mountains will remain recalcitrant based on conventional molecular methods. Because of a severe lack of resolution, none of the available taxonomic treatments for Oxytropis could either be confirmed or refuted based upon ITS and trnL-F. Nevertheless, we confirm the status of several species, and identify morphological or genetic particularities for some groups of species. The AHE approach yielded a highly supported phylogenetic tree, suggesting that increased taxon sampling coupled with AHE methods promise advances in the study of the taxonomy and evolution of Oxytropis, thus providing further analytical opportunities, such as diversification rate and biogeographical analyses.

Key words: Anchored Hybrid Enrichment, Fabaceae, Irano-Turanian region, Oxytropis, phylogeny, Qinghai-Tibet Plateau, taxonomy