DORMANCY AND GERMINATION CHARACTERSITICS OF TWO FLORIDA NATIVE FORBS, ASCLEPIAS HUMISTRATA AND LUPINUS DIFFUSUS By GABRIEL CAMPBELL A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2016 1 © 2016 Gabriel Campbell 2 To Mother Earth, may we learn to appreciate your giving and to understand your mystery 3 ACKNOWLEDGMENTS I would like to thank all of my friends and family for their kind words of encouragement and wisdom. I could not have completed this document without the support of Dr. Mack Thetford, Dr. Debbie Miller, and Dr. Hector Perez. A shout out to the Moore family, Anna Dicks, Blakely Gill and the Perez Seed Lab for collecting seeds and graciously volunteering their time and expertise. Lastly, I would like to thank everyone involved in the Environmental Horticulture Department at the University of Florida. 4 TABLE OF CONTENTS page ACKNOWLEDGMENTS .................................................................................................. 4 LIST OF TABLES ............................................................................................................ 7 LIST OF FIGURES .......................................................................................................... 8 ABSTRACT ................................................................................................................... 10 CHAPTER 1 INTRODUCTION AND LITERATURE REVIEW ..................................................... 12 Florida Panhandle and its Plants ............................................................................ 12 Florida Panhandle Sandhills and their Plants ......................................................... 12 Florida Panhandle Barrier Islands and their Plants ................................................. 13 Are Florida Ecosystems in a State of Crisis? .......................................................... 15 Restoration Ecology and Biodiversity...................................................................... 15 Seed Dormancy and Imbibition ............................................................................... 17 Experimental Preface.............................................................................................. 19 2 ASCLEPIAS HUMISTRATA SEED GERMINATION ............................................... 20 Introduction ............................................................................................................. 20 Asclepias .......................................................................................................... 20 Asclepias seed germination .............................................................................. 22 Asclepias humistrata ........................................................................................ 23 Materials and Methods............................................................................................ 24 Seed Collection and Storage ............................................................................ 24 Alachua County .......................................................................................... 25 Citrus County ............................................................................................. 25 Santa Rosa County .................................................................................... 26 Volusia County ........................................................................................... 27 Seed Characteristics ........................................................................................ 27 Seed Viability Tests .......................................................................................... 27 Seed Imbibition Tests ....................................................................................... 28 Germination Experiments ................................................................................. 28 Preliminary experiments ............................................................................ 29 Temperature gradient experiment .............................................................. 30 Follicle maturity experiment ....................................................................... 30 Seed size experiment ................................................................................ 31 Illumination experiment .............................................................................. 31 Statistical Analyses .......................................................................................... 31 Results .................................................................................................................... 32 Seed Characteristics ........................................................................................ 32 5 Seed Viability Tests .......................................................................................... 32 Seed Imbibition Tests ....................................................................................... 33 Germination Experiments ................................................................................. 33 Preliminary experiments ............................................................................ 33 Temperature gradient experiment .............................................................. 34 Follicle maturity experiment ....................................................................... 35 Seed size experiment ................................................................................ 35 Illumination experiment .............................................................................. 35 Discussion .............................................................................................................. 36 3 LUPINUS DIFFUSUS SEED GERMINATION ........................................................ 57 Introduction ............................................................................................................. 57 Lupinus ............................................................................................................. 57 Lupinus Seed Germination ............................................................................... 58 Lupinus diffusus ............................................................................................... 59 Fire and Seed Germination .............................................................................. 60 Experimental Preface ....................................................................................... 61 Materials and Methods............................................................................................ 61 Seed Collection and Storage ............................................................................ 61 Seed Viability Tests .......................................................................................... 62 Seed Imbibition Tests ....................................................................................... 63 Germination Experiments ................................................................................. 63 Smoke-infused water experiment ............................................................... 64 Rock polisher experiment........................................................................... 65 Freeze followed by hot bath experiment .................................................... 65 Scarification experiment ............................................................................. 66 Statistical Analyses .......................................................................................... 67 Results .................................................................................................................... 67 Seed Viability Tests .......................................................................................... 67 Seed Imbibition Tests ....................................................................................... 67 Germination Experiments ................................................................................. 67 Preliminary experiments ............................................................................ 67 Scarification experiment ............................................................................. 68 Discussion .............................................................................................................. 68 4 CONCLUSIONS ..................................................................................................... 80 APPENDIX A TETRAZOLIUM TESTING ...................................................................................... 81 B SURVIVAL ANALYSIS............................................................................................ 82 LIST OF REFERENCES ............................................................................................... 85 BIOGRAPHICAL SKETCH ............................................................................................ 96 6 LIST OF TABLES Table page 2-1 Summary of collection sites and seed characteristics for Ascelpias humistrata seedlots .............................................................................................................. 41 2-2 Viability percentages (n=100) using TZ staining of 13 Asclepias humistrata seedlots at different times after seed harvest. .................................................... 42 2-3 Effects of temperature and seedlot on germination probability