University of Kentucky UKnowledge University of Kentucky Doctoral Dissertations Graduate School 2004 MAINTENANCE OF SEXUALLY DIMORPHIC PATTERNS OF GROWTH AND REPRODUCTION IN MARCHANTIA INFLEXA Linda Catherine Fuselier University of Kentucky, [email protected] Right click to open a feedback form in a new tab to let us know how this document benefits ou.y Recommended Citation Fuselier, Linda Catherine, "MAINTENANCE OF SEXUALLY DIMORPHIC PATTERNS OF GROWTH AND REPRODUCTION IN MARCHANTIA INFLEXA" (2004). University of Kentucky Doctoral Dissertations. 267. https://uknowledge.uky.edu/gradschool_diss/267 This Dissertation is brought to you for free and open access by the Graduate School at UKnowledge. It has been accepted for inclusion in University of Kentucky Doctoral Dissertations by an authorized administrator of UKnowledge. For more information, please contact [email protected]. ABSTRACT OF DISSERTATION Linda Catherine Fuselier College of Arts and Sciences University of Kentucky 2004 MAINTENANCE OF SEXUALLY DIMORPHIC PATTERNS OF GROWTH AND REPRODUCTION IN MARCHANTIA INFLEXA ____________________________________ ABSTRACT OF DISSERTATION ____________________________________ A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the College of Arts and Sciences at the University of Kentucky By Linda Catherine Fuselier Lexington, Kentucky Co-Directors: Dr. D. Nicholas McLetchie, Associate Professor of Biology and Dr. R. Craig Sargent, Professor of Biology Lexington, Kentucky 2004 Copyright © Linda Catherine Fuselier 2004 ABSTRACT OF DISSERTATION MAINTENANCE OF SEXUALLY DIMORPHIC PATTERNS OF GROWTH AND REPRODUCTION IN MARCHANTIA INFLEXA Sexual dimorphism in life history traits may influence the distribution of the sexes, population sex ratios, the maintenance of sex in populations, and the evolutionary potential of a species. In bryophytes, sexual dimorphism in traits related to growth and reproduction may be responsible for female-biased population sex ratios and a lack of sexual reproduction. I examined the roles of natural selection in maintaining sexual dimorphism in the context of impacts on bryophyte population sex ratios, using Marchantia inflexa as a model system. My studies included an assessment of among- population variation in habitat use by the sexes, comparison of phenotypes between single-sex and both-sex populations, a field study of natural selection, and a comparison of the influence of selection on asexual and sexual fitness components. The sexes of M. inflexa were sexually dimorphic in investment in growth, asexual and sexual reproduction. The sexes were spatially separated in populations, but the sexes overlapped in habitat use. Populations differed in growth, asexual reproduction rates, degrees of sexual dimorphism, and strength of among-trait correlations. Plants from single-sex and both-sex populations differed in investment in growth and asexual reproduction, but the two population types showed the same degree of sexual dimorphism. Thus, local environment may be more influential than the presence of the opposite sex in maintaining sexual dimorphism. Selection on sexually dimorphic traits was both sex-specific and environmentally dependent. Between-sex correlations were not significant in the greenhouse but were significant in the field thus, evolution and expression of sexual dimorphism in nature may be constrained by among-trait and between-sex correlations. Additionally, females incurred a cost of plasticity that males did not. Because there was a negative trade-off between sexual and asexual fitness, overall lifetime selection may result in a different picture of how the sexes experience selection. The combination of sex-specific and environment-dependent selection, and sex-specific costs to plasticity may not only maintain sexually dimorphic traits but also ensure the persistence of both sexes in a population. KEYWORDS: Bryophyte, sexual dimorphism, selection, plasticity, liverwort Linda C. Fuselier March 6, 2004 MAINTENANCE OF SEXUALLY DIMORPHIC PATTERNS OF GROWTH AND REPRODUCTION IN MARCHANTIA INFLEXA By Linda Catherine Fuselier D. Nicholas McLetchie Co-Director of Dissertation Dr. R. Craig Sargent Co-Directors of Dissertation Dr. Peter Mirabito Director of Graduate Studies March 6, 2004 RULES FOR THE USE OF DISSERTATIONS Unpublished dissertations submitted for the Doctor’s degree and deposited in the University of Kentucky Library are as a rule open for inspection, but are to be used only with due regard to the rights of the authors. Bibliographical references may be noted, but quotations or summaries of parts may be published only with the permission of the author, and with the usual scholarly acknowledgements. Extensive copying or publication of the dissertation in whole or in part also requires the consent of the Dean of the Graduate School of the University of Kentucky. DISSERTATION Linda Catherine Fuselier College of Arts and Sciences University of Kentucky 2004 MAINTENANCE OF SEXUALLY DIMORPHIC PATTERNS OF GROWTH AND REPRODUCTION IN MARCHANTIA INFLEXA ____________________________________ DISSERTATION ____________________________________ A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the College of Arts and Sciences at the University of Kentucky By Linda Catherine Fuselier Lexington, Kentucky Co-Directors: Dr. D. Nicholas McLetchie, Associate Professor of Biology and Dr. R. Craig Sargent, Professor of Biology Lexington, Kentucky 2004 Copyright © Linda Catherine Fuselier 2004 This dissertation is dedicated to my mother and mentor, Marilyn Fuselier, for her support, encouragement, and confidence in me. ACKNOWLEDGEMENTS I especially thank all the folks that assisted in planting, greenhouse and field work including: L. Arrata, W. Bhawanie, K. Jackson, N. Jones, J. Penrose, C. Richardson, P. Runyan, N. Sudler, C. Sydney, S. Wapiti, J. Webb. Victor Rush and family helped with collections in Florida. Scott Gleeson provided growth room space, D.Nicholas McLetchie provided greenhouse space and taught me to propagate liverworts, and C. Fox gave me greenhouse space and lots of emotional support. Paul Davison helped me find collection locations, T. Sutton provided greenhouse assistance, and A. Whittemore verified specimen identifications. I thank P.Crowley, Wort Group and Plant Group for helpful discussions. Kathleen Donohue taught me about selection analyses and provided insight, thoughtful discussions, and endless help with manuscript review. Scott Gleeson and C. Baskin critiqued drafts of manuscripts. Susan Mopper helped with ideas for analyses and provided software and insight into population dynamics. Jon Shaw gave me insightful comments and invited me to his lab to work. My committee members, R. C. Sargent, D. N. McLetchie, S. Gleeson and C. Fox provided critical feedback and helpful suggestions throughout my program. I especially appreciate the support of the faculty that wrote letters for my job and grant applications; in particular, J. Krupa and C. Staben who wrote letters in support of my teaching experience. I thank T. Phillips, who acted as outside examiner for my dissertation defense. I thank Tennessee Wildlife Resources Agency and D. Oyer, manager of Buffalo Springs Fish Hatchery, for access to the Buffalo Springs field site, B. Stewart for access to additional Oklahoma sites, Chickasaw National Recreation Area for permission to collect plants, Florida Department of Environmental Protection for a collection permit, the Wildlife Section of the Forestry Division of the Republic of Trinidad and Tobago for collection and export permits and the Water and Sewage Authority in Trinidad for access to the Quare River site. University of Oklahoma Biological Station provided housing, greenhouse space and resources. The Department of Agronomy at the University of Kentucky provided greenhouse space, and University of Kentucky Regulatory Services conducted soil and tissue analyses. Many folks, especially Bev Taulby, in the Biology Department office helped manage grant funds and provided office support needed to complete my research. iii Travel to Trinidad was supported by NSF grant DEB 99074086 (D.N.McLetchie, Principal Investigator, P.H. Crowley co-PI). Funding for various aspects of my research were provided by University of Kentucky Graduate School, Department of Biology, Ribble Funds, a Kentucky Academy of Sciences Botany Fund Award, Sigma Delta Epsilon Vessa Notchev Fellowship, a grant from the Torrey Botanical Society, and a grant from the Botanical Society of America. I was supported by a Dissertation Year Fellowship through the University of Kentucky Graduate School to write my dissertation. iv TABLE OF CONTENTS Acknowledgements……………………………………………………………………………....iii List of Tables…………………………………………………………………………………....viii List of Figures…………………………………………………………………………………….ix List of Files………………………………………………………………………………………..x Chapter One: Sexual dimorphism in liverworts............................................................................. 1 Introduction................................................................................................................................. 1 Maintenance of sexual dimorphism............................................................................................ 2 Costs of sexual reproduction................................................................................................... 4 Trade-offs...............................................................................................................................