MEASURES OF FITNESS AND GENETIC VARIATION IN THE ENDANGERED HAWAIIAN GENUS HESPEROMANNIA

Transcription

1 MEASURES OF FITNESS AND GENETIC VARIATION IN THE ENDANGERED HAWAIIAN GENUS HESPEROMANNIA A THESIS SUBMITTED TO THE GRADUATE DIVISION OF THE UNIVERSITY OF HAWAI I IN PARTIAL FULFULLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN BOTANICAL SCIENCES (BOTANY- ECOLOGY, EVOLUTION, AND CONSERVATION BIOLOGY) DECEMBER 2003 By Susan Nalani Ching Harbin THESIS COMMITTEE Clifford W. Morden, Chairperson Gerald D. Carr David C. Duffy

2 Acknowledgements I would like to acknowledge the following people for their role in the completion of this thesis: My Committee for their wonderful editing and sincere interest in this project; Dr. Morden for his kind and insightful mentoring in the lab, in the field and in the classroom, and for all the helpful discussions on evolution and natural history; Dr. Carr for his editing insights and his motivating love of botanical taxonomy; Dr. Duffy for his interest and support in this project; Dr. Keeley and Dr. Chan for lab assistance; Also for their help in the lab and in the analyses of this research Dr. Alison Sherwood, Candace Felling, Maya LeGrande, Shelly Lammers, Christina Crooker, and Terry LeBeck; Nellie Sugii and the Lyon Arboretum Staff for creating a nurturing botanical environment to learn in; and Dr. Lamoureux for kindling my interests in conservation and Hawaiian natural history. I would also like to thank the following organizations and people for their generous time and money spent in helping with field collections: the US Army Garrison Environmental Unit, Dan Sailer with the Nature Conservancy, Randy Bartlett and Hank Oppenhiemer with Maui Land and Pineapple Co., Ken Wood and Steve Perlman, the National Tropical Botanical Gardens, and Vickie Caraway (DLNR). Funding for this research was provided by a grant from The Garden Club of Honolulu through the Lyon Arboretum and the Department of Botany through Dr. Morden. iii

3 Table of Contents Acknowledgements iii List of Tables.vii List of Figures...viii Chapter 1: Literature review and thesis proposal 1 Introduction: Island species at risk.. 1 The role of genetics in conservation 5 Conservation genetics of the Hawaiian Species of Hesperomannia...8 Taxonomic History..8 Description and Distribution of Species 11 Purpose of This Study 14 Formal Hypotheses 15 Materials and Methods...18 DNA Collections 18 DNA Extractions 19 RAPD Procedure 20 Pollen Viability Analysis...21 Germination Studies...21 Chapter 2: Measures of fitness and genetic variation in the endangered Hawaiian genus Hesperomannia Introduction 23 Materials and Methods...27 iv

4 Field Sites..27 DNA Collection.30 DNA Extraction.31 RAPD Procedure...32 Pollen Viability Analysis...33 Germination Observations.34 Genetic Data Analyses...35 Results 38 RAPD Data Analyses: Among Species Variation.38 Polymorphic loci 39 Heterozygosity estimates...41 Genetic similarity indices..44 Key to the Four Species of Hesperomannia..50 RAPD Data Analyses: Within Species Variation..51 Hesperomannia oahuensis.51 Hesperomannia arborescens.57 Hesperomannia swezeyi.63 Hesperomannia lydgatei 68 Pollen Viability Analysis...73 Germination Observations.74 Discussion..76 The Genus Hesperomannia 76 Hesperomannia oahuensis.78 v

5 Hesperomannia arborescens. 81 Hesperomannia swezeyi. 83 Hesperomannia lydgatei 86 Conclusions: recommendations for conservation..87 Chapter 3: Hypotheses revisited 92 Appendix A: RAPD Data for Hesperomannia oahuensis.96 Appendix B: RAPD Data for Hesperomannia arborescens 112 Appendix C: RAPD Data for Hesperomannia swezeyi Appendix D: RAPD Data for Hesperomannia lydgatei..160 Literature Cited 192 vi

6 List of Figures Figure Page 1.1 Hesperomannia arborescens Hesperomannia arbuscula Hesperomannia lydgatei Average estimated population level heterozygosity ranges for each species Average similarity ranges for each species PCO analysis for the genus Hesperomannia PCO analysis for individuals on O`ahu PCO analysis for H. oahuensis and H. arborescens Spatial correlation: geographic vs. genetic distance for the genus PCO analysis for H. oahuensis Spatial correlation: geographic vs. genetic distance for H. oahuensis Hesperomannia oahuensis Hesperomannia oahuensis Cluster analysis for H. oahuensis PCO analysis for H. arborescens Spatial correlation: geographic vs. genetic distance for H. arborescens Spatial correlation: geographic vs. genetic distance for H. arborescens individuals on West Maui Hesperomannia arborescens Cluster analysis for H. arborescens PCO analysis for H. swezeyi 60 viii

7 2.18 Cluster analysis for H. swezeyi Spatial correlation: geographic vs. genetic distance for H. swezeyi Spatial correlation: geographic vs. genetic distance for H. swezeyi, Ko`olau Mts. only Hesperomannia lydgatei PCO analysis for H. lydgatei Cluster analysis for H. lydgatei...66 ix

8 List of Tables Table Page 1.1 Defining characters for the three species of Hesperomannia Individuals sampled from each species of Hesperomannia Primer nucleotide sequence RAPD marker statistics for each Hesperomannia species Hierarchical structure of genetic diversity in species of Hesperomannia Similarity within and among species of Hesperomannia Similarity index for Hesperomannia oahuensis Similarity index for Hesperomannia arborescens Similarity index for Hesperomannia swezeyi Similarity index for Hesperomannia lydgatei Estimated pollen viability Average germination rates Percent polymorphic loci among Hawaiian species studied with RAPDs Comparison of expected heterozygosity and genetic identity of Hawaiian species studied with RAPDs 70 vii