J Syst Evol ›› 2022, Vol. 60 ›› Issue (3): 621-629.DOI: 10.1111/jse.12805

• Research Articles • Previous Articles     Next Articles

A biogeographical analysis of Muhlenbergia (Poaceae: Chloridoideae: Cynodonteae: Muhlenbergiinae)

Paul M. Peterson1*, Cristina Roquet2, Konstantin Romaschenko1,3, Yolanda Herrera Arrieta4, and Alfonso Susanna5   

  1. 1 Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013‐7012, USA
    2 Systematics and Evolution of Vascular Plants (UAB)—Associated Unit to CSIC, Departament de Biologia Animal, Biologia Vegetal i Ecologia, Facultat de Biociències, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
    3 M.G. Kholodny Institute of Botany, National Academy of Sciences, Kiev 01601, Ukraine
    4 Instituto Politécnico Nacional, CIIDIR Unidad‐Durango‐COFAA, Durango, C.P. 34220, Mexico
    5 Laboratory of Molecular Systematics, Botanic Institute of Barcelona (IBB‐CSIC‐ICUB), Passeig del Migdia s.n., 08038 Barcelona, Spain

    * Author for correspondence. E‐mail: peterson@si.edu
  • Received:2021-05-18 Accepted:2021-07-09 Online:2021-07-16 Published:2022-05-01

Abstract: A phylogeny based on the analysis of six DNA sequence markers (ITS, ndhA intron, rpl32-trnL, rps3, rps16 intron, and rps16-trnK) is used to infer ancestral areas and divergence times, and reconstruct the biogeographical history and evolution of 150 of the 183 (82%) species of Muhlenbergia. Our results suggest that the genus originated 9.3 mya in the Sierra Madre (Occidental and Oriental) in Mexico, splitting into six lineages: M. ramulosa diverging 8.2 mya, M. subg. Muhlenbergia at 5.9 mya, M. subg. Pseudosporobolus at 5.9 mya, M. subg. Clomena at 5.4 mya, M. subg. Bealia at 4.3 mya, and M. subg. Trichochloa at 1 mya, each of these with a high probability of Sierra Madrean origin. Our results further suggest that founder-event speciation from Sierra Madre to South America occurred independently multiple times in all five subgenera during the Pleistocene and late Pliocene. One long-distance dispersal event most likely originating from Central or Eastern North America to East and Central Asia occurred 1.6–1 mya in M. subg. Muhlenbergia. In our cladogram, members of M. subg. Trichochloa show little genetic resolution, suggesting very low levels of divergence among the species, and this may be a consequence of rapid radiation.

Key words: biogeography, classification, ITS, molecular phylogeny, Muhlenbergia, plastid DNA sequences