Evolution of floral and mating system variation in Camissoniopsis cheiranthifolia (Onagraceae): An evaluation of patterns and processes

II CO-AUTHORSHIP . IV Publications arising from and included in this thesis: . iv Publications arising from, but not included in this thesis: . v ACKNOWLEDGEMENTS . VI TABLE OF CONTENTS . VIII LIST OF TABLES . XII LIST OF FIGURES . XIV CHAPTER 1. GENERAL INTRODUCTION . 1 THEORETICAL FRAMEWORK . 2 Selective factors expected to cause and/or maintain mating system variation . 4 Testing theoretical predictions . 7 STUDY SPECIES . 8 Chapter Objectives . 10 REFERENCES . 14 CHAPTER 2. BROAD GEOGRAPHIC COVARIATION BETWEEN FLORAL TRAITS AND THE MATING SYSTEM IN CAMISSONIOPSIS CHEIRANTHIFOLIA (ONAGRACEAE): MULTIPLE STABLE MIXED MATING SYSTEMS ACROSS THE SPECIES’ RANGE? 24 ABSTRACT . 25 INTRODUCTION . 26 MATERIALS AND METHODS . 30 Study species . 30 Phenotypic and genetic variation in floral traits across the species’ range . 30 Geographic variation in self-incompatibility . 32 Other floral traits expected to covary with the mating system . 33 Geographic variation in outcrossing and its correlation with floral traits . 35 Covariation between outcrossing and floral traits within populations . 36 RESULTS . 36 Pattern of geographic variation in floral morphology . 36 Geographic variation in self-incompatibility . 38 Association among floral traits . 39 Geographic variation in outcrossing and correlation with floral traits . 40 Covariation between outcrossing and floral traits within populations . 41 DISCUSSION . 41 Covariation between floral traits and the mating system . 42 Multiple stable states of mating system evolution across the geographic range? 46 SUPPLEMENTARY INFORMATION – APPENDIX 1 . 51 FUNDING . 51 ACKNOWLEDGEMENTS . 52 ix LITERATURE CITED . 52 CHAPTER 3. EXPERIMENTAL AND GENETIC ANALYSES REVEAL THAT INBREEDING DEPRESSION DECLINES WITH INCREASED SELFFERTILIZATION AMONG POPULATIONS OF A COASTAL DUNE PLANT . 67 ABSTRACT . 68 INTRODUCTION . 69 MATERIALS AND METHODS . 74 Study species and population sampling . 74 Experimental analysis of inbreeding depression in contrasting glasshouse environments . 76 Population-genetic analysis of inbreeding depression . 80 RESULTS . 81 Pre-dispersal inbreeding depression for fruit set and seeds per fruit . 81 Post-dispersal inbreeding depression before soil moisture treatment. 81 Cumulative post-dispersal inbreeding depression across soil moisture treatments . 82 Population genetic analysis . 83 DISCUSSION . 84 Experimental vs. population-genetic estimates of inbreeding depression . 85 Variation in the expression of inbreeding depression across the life cycle and in different environments . 87 Maintenance of inbreeding depression despite chronic selfing? 89 The role of inbreeding depression in maintaining mating system variation . 91 ACKNOWLEDGEMENTS . 93 REFERENCES . 93 SUPPORTING INFORMATION – APPENDIX 2 . 100 CHAPTER 4. POLLEN LIMITATION AND FLORAL PARASITISM AS POSSIBLE FACTORS UNDERLYING STRIKING DIFFERENTIATION OF THE MATING SYSTEM IN A PACIFIC COASTAL DUNE PLANT . 108 ABSTRACT . 109 INTRODUCTION . 110 MATERIALS AND METHODS . 115 Study species . 115 Patterns of variation in fruit set . 116 Associations between flower size, bud parasitism and fruit set . 118 Pollen supplementation experiment . 120 Depression of fruit set by bud parasitism alone . 123 RESULTS . 124 Association between flower size and fruit set . 124 Association between flower and bud size, bud parasitism and fruit set . 125 Pollen supplementation experiment . 128 Depression of fruit set by bud parasitism alone . 130 DISCUSSION . 130 Covariation between the mating system and pollen limitation . 130 Fitness effects of floral parasitism . 134 Does floral morphology influence the risk of parasitism? 136 CONCLUSIONS . 138 x ACKNOWLEDGEMENTS . 139 LITERATURE CITED . 140 SUPPLEMENTARY INFORMATION – APPENDIX 3 . 146 CHAPTER 5. EXPERIMENTAL MANIPULATION OF FLOWERS TO DETERMINE THE FUNCTIONAL MODES AND FITNESS CONSEQUENCES OF SELF-FERTILIZATION: UNEXPECTED OUTCOME REVEALS KEY ASSUMPTIONS . 158 SUMMARY . 159 INTRODUCTION . 160 MATERIALS AND METHODS . 166 Effect of emasculation a