Genetics and Evolution of Ultraviolet Reflectance in Flowers
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University of Calgary PRISM: University of Calgary's Digital Repository Graduate Studies The Vault: Electronic Theses and Dissertations 2018-01-25 Genetics and evolution of ultraviolet reflectance in flowers Liu, Yan Liu, Y. (2018). Genetics and evolution of ultraviolet reflectance in flowers (Unpublished doctoral thesis). University of Calgary, Calgary, AB. doi:10.11575/PRISM/5440 http://hdl.handle.net/1880/106359 doctoral thesis University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission. Downloaded from PRISM: https://prism.ucalgary.ca UNIVERSITY OF CALGARY GENETICS AND EVOLUTION OF ULTRAVIOLET REFLECTANCE IN FLOWERS by Yan Liu A THESIS SUBMITTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY GRADUATE PROGRAM IN BIOLOGICAL SCIENCES CALGARY, ALBERTA JANUARY, 2018 © Yan Liu 2018 Abstract Many flowers have ultraviolet (UV) reflectance patterns, which are invisible to humans but visible to pollinators, such as bumblebees and hummingbirds. In bees and hummingbirds, photoreceptors are sensitive to UV wavelengths, and it is therefore necessary to incorporate this variable to model pollinators’ perception and assess floral UV evolution. In this thesis, I explore micro- and macroevolutionary patterns in floral UV patterns, specifically concentrating on the effect of this phenotype on pollinators. I first explore the ways in which UV patterns can be measured and characterized, as well as explore the underlying basis of UV patterning in flowers. By gathering UV reflectance data (between 300 to 400nm) on 150 species, I found evidence that the phylogenetic distribution of UV trait disparity is consistent with a stabilizing selection model of evolution, but the magnitude of stabilizing selection varies with geography and pollinator syndrome. Mimulus species have become key model species for investigating the genetics of floral adaptations, in part because it is tremendous diversity in floral phenotypes. I firstly estimate genetic diversity in six populations in Alberta and British Columbia. Historical contingency (via geographic and bioclimatic events) provides the evidence of restricted gene flow. Variance in phenotypes depends not only on allelic interactions but also on environmental factors. Variation and heritability of the floral UV reflectance are further explored with experimental interspecific crosses between Mimulus guttatus and Mimulus luteus. By recoding 12 floral traits throughout the parental to F4 generations, I find that phenotypic covariance is strongest between UV reflectance and other floral traits, lending evidence to the idea that UV reflectance in flowers evolves along with other floral traits as a response to selection from pollinators. My research has implications for forecasting plant adaptation through hybridization and polyploidization, which may occur in concert with the evolution of plant-pollinator relationships. ii Acknowledgements I am deeply grateful to Dr. Jana Vamosi, my PhD supervisor. First and foremost, she gave me the precious opportunity to study in the PhD program. I worked and learned with her for five years, and I received the direction to my scientific and career development. Jana will always be there with her students when we are having a difficult time. I will never forget every encouragement and support she gave to me when I felt overwhelmed and confused. This dissertation would not have been possible without efforts of my supervisor, Jana. Thanks go also to my previous and present committee members, Dr. Marcus Samuel, Dr. Dae-Kyun Ro, Dr. Amanda Melin (Department of Anthropology and Archaeology & Department of Medical Genetics), Dr. Christina Caruso (University of Guelph), Dr. Edward Yeung and Dr. Brian Kooyman (Department of Anthropology & Archaeology), who provided invaluable discussion and suggestion to my PhD research, candidate exam and thesis writing. Studying in Jana’s lab, the team has been invaluable in my PhD journey, as both colleagues and friends, especially Soraya Villalobos, Lisa Cahoon, Dr. Yanbing Gong (Visiting Scholar). Here's to the many years we spent together! I want to thank my Masters supervisor Dr. Daoyuan Zhang (Chinese Academy of Sciences) and my undergraduate supervisor Dr. Yanmin Wei (Beijing Agricultural University). They are all graceful and knowledgeable female scientists in China. The experience working with them has always encouraged me to be a good female researcher in the future. I also greatly appreciate Dr. Xiaoxiao Liu (Department of geography), Dr. Hongxiang Zhang (Chinese Academy of Sciences), Dr. Qiushi Li, Yingying Cong. They are both my friends and academic cooperators, and especially appreciate to my best research partner Dr. Jiancheng Wang (Chinese Academy of Sciences). How lucky I am to have you in my life. iii Big thank to Dr. Chendanda Chinnappa, Dr. Sarah E.J.Arnold (FReD database), Dr. Benjamin Blackman (University of California) and Ian D. Macdonald (plant collector) for their help and support to my PhD research. I enjoyed the moments to work with the students in Dr. Sean Rogers lab, Dr. Lawrence Harder lab and Dr. Dae-Kyun Ro lab. Thanks for their help and company, especially Dr. Matthew Morris, Dr. Ella Bowles, Dr. Qiqun Cheng (Visiting Scholar), and Dr. Mason Kulbaba. As an international student and first coming to Canada, I got a lot of help and encouragement from many staff in the Department of Biological Sciences. I would like to express my sincere appreciation to Dianne White, Bonnie Smith, Karen Barron and Christine Goodwin. I am thankful for the hardworking research assistants in my projects, they are Moin Tinwala, Sophia Shah, Khanjan Pandya, Maegan Lacuata, Safaa Al-Khaz'Aly, Alexander Chiem and Juliana Abbatia. My research was funded by the grants from Alberta Innovates-Technology Futures (AITF), Alberta Conservation Association (ACA), and University of Calgary. Mimulus specimen were loaned from University of Calgary Herbarium (UAC), University of Alberta Herbarium (ALTA), and University of Lethbridge Herbarium (LETH). Thank you for all the support! My lovely parents are always proud of my study and constantly support my decisions. I love them forever! In the end, I want to talk to myself “More powerful more responsibility, you did a great job! Enjoy your next adventure!” iv Dedication This thesis is dedicated to my family. My parents, Zhongqiao Liu and Xingai Wang. 谨以我的博士论文,献给爱我的和我爱的人一直以来的期许和关爱! v Table of Contents Abstract .............................................................................................................................. ii Acknowledgements .......................................................................................................... iii Dedication ...........................................................................................................................v Table of Contents ............................................................................................................. vi List of Tables .................................................................................................................... ix List of Figures and Illustrations ..................................................................................... xi List of Symbols, Abbreviations and Nomenclature .................................................... xiii 1 CHAPTER 1 GENERAL INTRODUCTION ........................................................1 1.1 Introduction of UV reflectance from flowers and pollinator-flower interaction 1 1.2 Introduction of the floral colours transitions and the correlation with floral UV reflection .................................................................................................................2 1.3 Flower and pollinator interaction.........................................................................4 1.4 Inner epidermis between UV reflectance and UV absorbing flowers ...............6 1.5 Introduction to the study system: Mimulus guttatus ...........................................7 1.6 Thesis objectives .....................................................................................................8 2 CHAPTER 2 The adaptive value of floral UV reflectance: a comparative investigation of floral traits, geography and bee visitation .................................13 2.1 Introduction ..........................................................................................................13 2.2 Materials and Methods ........................................................................................18 2.2.1 Study system ...................................................................................................18 2.2.2 UV measurement ............................................................................................19 2.2.3 Quantifying phylogenetic signal ...................................................................20 2.2.4 Comparative analyses ....................................................................................22 2.2.5 Model selection ...............................................................................................22 2.2.6 Phylomorphospace approach ........................................................................24 2.3