A Perennial Flax (Linum spp.) Breeding Program Using Ideotype Models to Select for Oilseed, Garden, and Cut Flower Cultivars A THESIS SUBMITTED TO THE FACULTY OF THE GRADUATE SCHOOL OF THE UNIVERSITY OF MINNESOTA BY David Gregory Tork IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE Neil O. Anderson and Donald L. Wyse March 2021 © David Tork 2021 Acknowledgements I would like to thank my advisors, Dr. Neil O Anderson and Dr. Donald L. Wyse, for guiding me through my graduate education, and for providing the opportunity to participate in the Forever Green perennial flax breeding program. It has been the greatest learning experience of my life, and I am honored to have received your mentorship and generous support. I would also like to thank my committee members, Dr. Eric Watkins and Dr. Stan Hokanson, for their excellent advice and instruction over the years. I am grateful to Kevin Betts and Donn Vellekson for providing tools and expertise in support of aspects of the project related to agronomy and seed production. For greenhouse support, I would like to thank the PGF team, including Pam Warnke, Tha Cha, and Dean Ziertman. Many thanks are also owed to those who have assisted with the upkeep of our various field sites, including Blake Webster and Kimon Karelis at the Rosemount Research and Outreach Center; Steve Poppe at the West Central Research and Outreach Center; Keith Mann, Crystal Sucher, and Rosmanita Learmont at the North Central Research and Outreach Center. Thank you to all the past and present members of the Anderson-Smith lab group for your helpful feedback and lively discussions. Funding for this project was provided by the Minnesota Department of Agriculture Clean Water Fund. I am also appreciative of several awards that provided financial support, including the Altman Family Scholarship, the Federated Garden Clubs of Minnesota scholarship, and the National Association of Plant Breeders Borlaug Scholars Program. A special thanks also to my Borlaug Scholars mentor, Dr. Donn Cummings, for his thoughtful guidance throughout the last year of my graduate program. Lastly, I would like to thank my friends, family, mentors, and prior teachers for their encouragement and support throughout the years. I am forever grateful to my parents, Brian and Sara Tork, for inspiring me to work hard, pursue my passions in life, and strive to grow every day. To my partner, Hanna Hudepohl, thank you for walking this path with me, and for your unwavering support and endless patience, especially when the going got tough. i Dedication This thesis is dedicated to my late grandfather Dr. James R. King, a Professor of History, and a lasting inspiration for my academic work. Your lessons continue to guide my path, and your “incurable optimism” is an ideal that I aspire to every day. ii Table of Contents List of Tables ................................................................................................................... vii List of Figures ................................................................................................................ xvii Chapter 1 ........................................................................................................................... 1 Literature Review ........................................................................................................ 1 Introduction ..................................................................................................... 1 History of flax cultivation and usage to the present day ................................. 1 Future sources of demand for flaxseed ........................................................... 5 History of flax in Minnesota ........................................................................... 8 Prior flax breeding at the University of Minnesota ........................................ 9 Justification for a new perennial flax breeding program .............................. 10 Resources for perennial flax breeding .......................................................... 15 Domestication of perennial grain crops ........................................................ 17 Ideotype breeding.......................................................................................... 20 Summary ....................................................................................................... 22 Tables ......................................................................................................................... 23 Figures ....................................................................................................................... 25 iii Chapter 2 ......................................................................................................................... 28 Selection of Perennial Flax (Linum spp.) for Yield, Reproductive, and Plant Habit Traits to Achieve Oilseed, Cut Flower, and Herbaceous Perennial Ideotypes ................. 28 Introduction ................................................................................................................ 29 Materials and Methods .............................................................................................. 36 Experiment 1 ................................................................................................. 36 Experiment 2 ................................................................................................. 47 Results and Discussion .............................................................................................. 49 Experiment 1 ................................................................................................. 49 Experiment 2 ................................................................................................. 74 Implications for breeding .............................................................................. 78 Conclusions ................................................................................................... 84 Tables ......................................................................................................................... 88 Figures ..................................................................................................................... 108 Chapter 3 ....................................................................................................................... 115 Perennial flax: A Potential Cut Flower Crop ........................................................... 115 Introduction .............................................................................................................. 116 Materials and Methods ............................................................................................ 120 iv Experiment 1 ............................................................................................... 120 Experiment 2 ............................................................................................... 122 Data collection (Experiments 1 & 2) .......................................................... 126 Results and Discussion ............................................................................................ 129 Experiment 1 ............................................................................................... 129 Experiment 2 ............................................................................................... 134 Conclusions.............................................................................................................. 144 Tables ....................................................................................................................... 147 Figures ..................................................................................................................... 163 Chapter 4 ....................................................................................................................... 166 Controlled Freezing Studies as a Corollary Selection Method for Winter Hardiness in Perennial Flax (Linum spp.) ............................................................................................ 166 Introduction .............................................................................................................. 167 Materials and Methods ............................................................................................ 171 Results and Discussion ............................................................................................ 178 Conclusions.............................................................................................................. 188 Tables ....................................................................................................................... 190 Figures ..................................................................................................................... 212 v References ...................................................................................................................... 222 Appendix A .................................................................................................................... 238 Chapter 2 supplemental tables ................................................................................. 238 Chapter 2 supplemental figures ............................................................................... 240 Appendix B .................................................................................................................... 251 Chapter 4