INHERITANCE OF MORPHOLOGICAL CHARACTERS OF PICKERELWEED (Pontederia cordata L.) By LYN ANNE GETTYS 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 2005 Copyright 2005 by Lyn Anne Gettys ACKNOWLEDGMENTS I would like to thank Dr. David Wofford for his guidance, encouragement and support throughout my course of study. Dr. Wofford provided me with laboratory and greenhouse space, technical and financial support, copious amounts of coffee and valuable insight regarding how to survive life in academia. I would also like to thank Dr. David Sutton for his advice and support throughout my program. Dr. Sutton supplied plant material, computer resources, career advice, financial support and a long-coveted copy of Gray’s Manual of Botany. Special thanks are in order for my advisory committee. Dr. Paul Pfahler was an invaluable resource and provided me with laboratory equipment and supplies, technical advice and more lunches at the Swamp than I can count. Dr. Michael Kane contributed samples of his extensive collection of diverse genotypes of pickerelweed to my program. Dr. Paul Lyrene generously allowed me to take up residence in his greenhouse when my plants threatened to overtake all of Gainesville. My program could not have been a success without the help of Dr. Van Waddill, who provided significant financial support to my project. I appreciate the generosity of Dr. Kim Moore and Dr. Tim Broschat, who allowed me to use their large screenhouses during my tenure at the Fort Lauderdale Research and Education Center. Thanks also go to my friends and advocates at the FLREC: Nancy Gaynor, Joanne Korvick, Luci Fisher and Susan Thor for technical and greenhouse assistance; Bill and Sarah Kern for identifying greenhouse critters; Bill Latham for providing me with access to the iii chemistry lab; and Bridge Desoran and his crew for building anything I asked them to in a completely unreasonable timeframe. I extend my sincere appreciation to Mr. Eric Ostmark and Mr. Doug Manning for providing technical support to my program in Gainesville. Thanks are also in order to Dr. Eastonce Gwata and Ms. Gabriela Luciani for helping out when I was in a bind and to the faculty and graduate students of the Agronomy Department for providing moral support throughout my tenure at the University of Florida. I truly appreciate the assistance provided by Kim, Paula, Sandy and Nancy (in Gainesville) and Cherie, Sarah, Veronica and Sue (in Fort Lauderdale), who helped navigate the labyrinth of paperwork to ensure that I got paid on time. I am eternally grateful to my family for their unflagging support of this and all of my endeavors. My parents, Mykel and Jody have been and continue to be my most enthusiastic cheerleaders; without their support I would probably be running a print shop somewhere. Thanks also go to Mr. Paul J. Best II, who provided unwavering friendship, moral support and a nice swampy home for my culled plants and to Dr. Ed Duke for being a fantastic mentor, advisor, inspiration and friend. Finally, I would like to thank the University of Florida Alumni Association for providing me with a 4-year Outstanding Alumni Fellowship and the Crop Science Society of America for awarding me a Gerald O. Mott Scholarship. iv TABLE OF CONTENTS page ACKNOWLEDGMENTS ................................................................................................. iii LIST OF TABLES........................................................................................................... viii LIST OF FIGURES ......................................................................................................... xiii ABSTRACT..................................................................................................................... xvi CHAPTER 1 INTRODUCTION AND OVERVIEW ........................................................................1 2 A REVIEW OF THE LITERATURE ..........................................................................3 Economic Importance...................................................................................................3 Classification, Origin and Distribution.........................................................................4 Morphology ..................................................................................................................6 Culture ..........................................................................................................................8 Propagation and Dormancy ..........................................................................................8 General Heteromorphic Incompatibility.....................................................................12 General Tristyly..........................................................................................................12 Morph Inheritance in Tristylous Species....................................................................14 Population Structure of Tristylous Species.................................................................15 Breakdown of Tristyly................................................................................................15 Cryptic Self-incompatibility .......................................................................................17 Prevalence of Tristyly in Species of the Pontederiaceae............................................19 Self-incompatibility in Species of the Pontederiaceae ...............................................20 Morph Inheritance in Species of the Pontederiaceae..................................................20 Morph Inheritance in Pickerelweed............................................................................21 Pollen Diameter Trimorphism and Production in Pickerelweed ................................21 Floral Structure and Reproductive Organ Arrangement in Pickerelweed..................22 Pollen Physiology and Male Fitness in Pickerelweed ................................................25 Self, Intramorph and Intermorph Compatibility in Pickerelweed ..............................26 Pollen Growth in vivo.................................................................................................27 Population Structure of Pickerelweed ........................................................................28 Impact of Pollinator Behavior ....................................................................................28 Stigmatic Pollen Loads in Pickerelweed ....................................................................31 Greenhouse Production vs. Natural Populations of Pickerelweed .............................32 v 3 POLLEN GRAIN DIAMETER, IN VITRO POLLEN GERMINATION AND REGRESSION BETWEEN GRAIN DIAMETER AND IN VITRO GERMINATION ........................................................................................................42 Introduction.................................................................................................................42 Materials and Methods ...............................................................................................46 Results and Discussion ...............................................................................................50 Conclusions.................................................................................................................52 4 DEVELOPMENT OF NOVEL POLLINATION TECHNIQUES TO REDUCE SELF-INCOMPATIBILITY RESULTING FROM HERKOGAMY........................59 Introduction.................................................................................................................59 Materials and Methods ...............................................................................................62 Results and Discussion ...............................................................................................66 Conclusions.................................................................................................................69 5 OPTIMUM SEED STORAGE AND GERMINATION CONDITIONS...................79 Introduction.................................................................................................................79 Materials and Methods ...............................................................................................81 Results and Discussion ...............................................................................................85 Conclusions.................................................................................................................90 6 INHERITANCE AND GENETIC CONTROL OF ALBINISM .............................104 Introduction...............................................................................................................104 Materials and Methods .............................................................................................105 Results and Discussion .............................................................................................105 Conclusions...............................................................................................................115 7 INHERITANCE AND GENETIC CONTROL OF FLOWER COLOR..................143 Introduction...............................................................................................................143 Materials and Methods .............................................................................................144 Results and Discussion