THE EVOLUTION AND SYSTEMATICS OF THE Opuntia humifusa COMPLEX By LUCAS C. MAJURE A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2012 1 © 2012 Lucas C. Majure 2 To my amazing and ever-supportive parents, Terrence and Diana Majure, my incredible wife Mariela Pajuelo, and beautiful son Gabriel 3 ACKNOWLEDGMENTS I thank my advisors, Drs. Douglas E. and Pam S. Soltis, and Walter S. Judd for their utmost support, enthusiasm, critical guidance, and encouragement throughout my PhD program. I thank my committee member Marc Branham for his help and ideas with my project. I also thank current and former members of the Soltis Lab (Monica Arakaki, Samuel Brockington, Charlotte Germain-Aubrey, Maribeth Latvis, Nicolas Miles, Michael J. Moore, Stein Servick, Victor Suarez), the herbarium FLAS (Richard Abbott, Paul Corogin, Lorena Endara, Mark Whitten, Kurt Neubig, Kent Perkins, Norris Williams), and the Department of Biology for their support and help throughout my degree. I thank my collaborators, Raul Puente, M. Patrick Griffith, and Donald J. Pinkava for their expertise. I also thank those institutions and people who provided me with specimens for use in this work and/or aided with fieldwork: Desert Botanical Garden (DBG), Eastern Kentucky University herbarium (EKY), Huntington Botanical Garden (HBG), Illinois Natural History Survey (ILLS), Louisiana State University herbarium (LSU), Miami University Herbarium (MU), Missouri Botanical Garden (MO), New York Botanical Garden (NY), Rancho Santa Ana Botanical Garden, Smithsonian Institution (US), Troy University herbarium (TROY), University of Alabama (UNA), University of Miami herbarium (MU), University of Michigan herbarium (MICH), University of North Carolina (UNC), University of Tennessee herbarium (TENN), University of Wisconsin (WIS). Ron Altig, Frank Axelrod, Marc Baker, Bryan Connolly, Tony Frates, Ty Harrison, Jovonn Hill, George Johnson, Terry Majure, Tom Mann, Ivan Marino, Michael J. Moore, Bill Nichols, Brent Patenge, Kevin Philley, George Phillips, Michael Powell, Kenneth Quinn, Chris Reid, Eric Ribbens, Barry Snow, Dean Spallone, Heather Sullivan, Blake Wellard, Theo Witsell, Dorde Woodruff. I thank my Master’s adviser, Gary N. Ervin for convincing me to work with Opuntia in the beginning and for his continued support and encouragement. I thank the late Dr. Lyman Benson for all of 4 the work he carried out in Opuntia. This work would not have been possible otherwise. Financial support for this work was provided in part by the Cactus and Succulent Society of America, the Botanical Society of America, American Society of Plant Taxonomists, the New England Botanical Club, the Florida Division of Forestry, and an NSF Dissertation Improvement Grant (DDIG-DEB-#1011270). 5 TABLE OF CONTENTS page ACKNOWLEDGMENTS ...............................................................................................................4 LIST OF TABLES ...........................................................................................................................9 LIST OF FIGURES .......................................................................................................................10 ABSTRACT ...................................................................................................................................12 CHAPTER 1 GENERAL INTRODUCTION ..............................................................................................14 2 PHYLOGENY OF Opuntia S.S. (CACTACEAE): CLADE DELINEATIONS, GEOGRAPHIC ORIGINS, AND RETICULATE EVOLUTION .........................................18 Background .............................................................................................................................18 Material and Methods .............................................................................................................23 Taxon Sampling ...............................................................................................................23 DNA Extraction, PCR, Sequencing, Sequence Editing, and Alignment .........................23 Phylogenetic Analyses .....................................................................................................25 Biogeographic Analysis and Divergence Time Estimation .............................................27 Results.....................................................................................................................................29 Relationships in Opuntieae ..............................................................................................30 Opuntia s.s. ......................................................................................................................31 Interclade Allopolyploids and Hybrids ...........................................................................31 Intraclade Allopolyploids ................................................................................................34 Biogeography and Divergence Time Estimation of Opuntia s.s. ....................................35 Discussion ...............................................................................................................................36 Consolea ..........................................................................................................................36 Opuntia lilae and Opuntia schickendantzii .....................................................................37 Nopalea ............................................................................................................................38 South-North American Disjunction in Opuntia ..............................................................38 The North American Radiation .......................................................................................41 Reticulate Evolution in Opuntia ......................................................................................41 Summary .................................................................................................................................44 3 Opuntia lilae, ANOTHER Tacinga HIDDEN IN Opuntia S.L. (CACTACEAE) .................55 Background .............................................................................................................................55 Materials and Methods ...........................................................................................................57 Taxon Sampling and Phylogenetic Analysis ...................................................................57 Ancestral State Reconstruction ........................................................................................58 Results.....................................................................................................................................58 Phylogenetic and Morphological Analysis ......................................................................58 6 Ancestral State Reconstruction ........................................................................................59 Discussion ...............................................................................................................................61 4 A CASE OF MISTAKEN IDENTITY, Opuntia abjecta, LONG-LOST IN SYNONYMY UNDER THE CARIBBEAN SPECIES, O.triacantha, AND REASSESSMENT OF THE ENIGMATIC O. cubensis ........................................................67 Background .............................................................................................................................67 Materials and Methods ...........................................................................................................69 Results.....................................................................................................................................70 Phylogeny ........................................................................................................................70 Morphology — O. abjecta vs. O. triacantha ..................................................................71 Morphology — O. militaris vs. O. triacantha .................................................................72 Morphology — O. cubensis vs. O. ochrocentra .............................................................73 Key to the Species ...........................................................................................................74 Discussion ...............................................................................................................................75 Opuntia abjecta vs. O. triacantha ...................................................................................75 O. militaris vs. O. triacantha ...........................................................................................77 The Opuntia cubensis Enigma .........................................................................................78 Summary .................................................................................................................................79 5 CYTOGEOGRAPHY OF THE Humifusa CLADE OF Opuntia S.S. MILL. 1754 (CACTACEAE, OPUNTIOIDEAE, OPUNTIEAE): CORRELATIONS WITH PLEISTOCENE REFUGIA AND MORPHOLOGICAL TRAITS IN A POLYPLOID COMPLEX .............................................................................................................................83 Background .............................................................................................................................83