University of Kentucky UKnowledge Theses and Dissertations--Plant and Soil Sciences Plant and Soil Sciences 2020 Arthropod Resistant Tomatoes: Screening Tools, Yield and Nutritional Quality of Interspecific Hybrids Mohammad Hasan Salman Ali Dawood University of Kentucky, [email protected] Digital Object Identifier: https://doi.org/10.13023/etd.2020.090 Right click to open a feedback form in a new tab to let us know how this document benefits ou.y Recommended Citation Dawood, Mohammad Hasan Salman Ali, "Arthropod Resistant Tomatoes: Screening Tools, Yield and Nutritional Quality of Interspecific Hybrids" (2020). Theses and Dissertations--Plant and Soil Sciences. 128. https://uknowledge.uky.edu/pss_etds/128 This Doctoral Dissertation is brought to you for free and open access by the Plant and Soil Sciences at UKnowledge. It has been accepted for inclusion in Theses and Dissertations--Plant and Soil Sciences by an authorized administrator of UKnowledge. For more information, please contact [email protected]. STUDENT AGREEMENT: I represent that my thesis or dissertation and abstract are my original work. Proper attribution has been given to all outside sources. I understand that I am solely responsible for obtaining any needed copyright permissions. I have obtained needed written permission statement(s) from the owner(s) of each third-party copyrighted matter to be included in my work, allowing electronic distribution (if such use is not permitted by the fair use doctrine) which will be submitted to UKnowledge as Additional File. I hereby grant to The University of Kentucky and its agents the irrevocable, non-exclusive, and royalty-free license to archive and make accessible my work in whole or in part in all forms of media, now or hereafter known. I agree that the document mentioned above may be made available immediately for worldwide access unless an embargo applies. I retain all other ownership rights to the copyright of my work. I also retain the right to use in future works (such as articles or books) all or part of my work. I understand that I am free to register the copyright to my work. REVIEW, APPROVAL AND ACCEPTANCE The document mentioned above has been reviewed and accepted by the student’s advisor, on behalf of the advisory committee, and by the Director of Graduate Studies (DGS), on behalf of the program; we verify that this is the final, approved version of the student’s thesis including all changes required by the advisory committee. The undersigned agree to abide by the statements above. Mohammad Hasan Salman Ali Dawood, Student Dr. John C. Snyder, Major Professor Dr. Mark Coyne, Director of Graduate Studies Arthropod Resistant Tomatoes: Screening Tools, Yield and Nutritional Quality of Interspecific Hybrids ________________________________________ DISSERTATION ________________________________________ A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the College of Agriculture, Food and Environment at the University of Kentucky By Mohammad Hasan Salman Ali Dawood Lexington, Kentucky Director: Dr. John C Snyder, Associate Professor Lexington, Kentucky 2020 Copyright © Mohammad Hasan Salman Ali Dawood 2020 ABSTRACT OF DISSERTATION Arthropod Resistant Tomatoes: Screening Tools and Yield and Nutritional Quality of Interspecific Hybrids Tomato (Solanum lycopersicum) is one of the most economically important vegetable crops grown around globe but is a host for numerous pests and pathogens. In the future, tomato breeders will have to focus on increasing fruit quantity and on enhancing pest resistance. Many accessions of the wild relative of tomato, S. habrochaites display high levels of resistance towards arthropods such as spider mites. The presence of the sesquiterpene hydrocarbon, 7-epi-zingiberene, found in S. habrochaites type IV trichomes has been associated with arthropod resistance. However, the presence of other compounds in its trichome secretions may also be related to arthropod resistance. One goal of this research was to evaluate the potential for using a spectrophotometer to enable accurate selection for 7-epi-zingiberene content by breeders. Another objective was to identify and evaluate the relative antixenotic activities on spider mites of major components present in the trichome secretions of a wild tomato. The third objective was to evaluate yield, 7-epi- zingiberene content and fruit nutrient quality in advanced interspecific hybrid lines to demonstrate that high yield and high zingiberene content have been successfully combined, and also to evaluate nutritional aspects of fruit quality of these hybrids such as phenolic content, lycopene, soluble solids, and ascorbic acid. Results for the first objective included identification of two novel compounds present in wild tomato trichome secretions as hydroxy-zingiberene and 9-hydroxy-10,11-epoxy-zingiberene. The spider mite repellency of each of these compounds was at least five times greater than that of 7- epi-zingiberene. The results for objective two showed that a spectrophotometer could be a very valuable tool for aiding selection of plants having high levels of 7-epi-zingiberene on their leaves and having low levels of other compounds such as monoterpenes, which are present on arthropod –susceptible tomato plants. Completion of the third objective indicated that high yield has been successfully combined with high 7-epi-zingiberene concentration and that the nutritional value of the fruit in the hybrids is at least equal to the recurrent parent and in some cases, the interspecific hybrids may be useful for improving tomato fruit nutritional content including: phenolics, lycopene, soluble solids, and ascorbic acid. In general, the phenolic content of interspecific hybrid tomatoes ranged from 325 to 427 μg/g fresh fruit, lycopene content ranged from 31 to 66 μg/g and soluble solids ranged from 4 to 7.8%, whereas those characteristics were lower in cultivated tomato hybrids. Ascorbic acid typically ranged between 483 and 498 μg/g fresh fruit in interspecific hybrids and was higher than that in cultivated tomato hybrids (337 μg/g). For future prospects, it may be possible to breed genotypes that have high yield, have improved nutritional value and are also resistant to arthropod pests. KEYWORDS: Tomato, spider mites, repellency, 7-epi-zingiberene, 9-hydroxy- zingiberene, yield, phenolic, UV-absorbance, Solanum habrochaites Mohammad Hasan Salman Ali Dawood 04/25/2020 Arthropod Resistant Tomatoes: Screening Tools and Yield and Nutritional Quality of Interspecific Hybrids By Mohammad Hasan Salman Ali Dawood Dr. John C. Snyder Director of Dissertation Dr. Mark Coyne Director of Graduate Studies 04-25-2020 Date This Dissertation is dedicated to the memory of a brave and humble soldier, my beloved cousin Arjan Elias Dawood. In June 2014, he was killed by terrorists in Mosul city, North Iraq. ACKNOWLEDGMENTS I am pleased to express my deepest gratitude to Dr. John C. Snyder, my supervisor at the University of Kentucky, Department of Horticulture for his support and advice on many aspects of my studies over several years. I would also like to thank the members of my advisory committee, Dr. Timothy Phillips, Dr. Barbara Liedl, Dr. Paul Vincelli and Dr. Kenneth Haynes. To the staff and graduate students of the Horticulture Department, University of Kentucky, I would like to express my deepest appreciation for their advice and support. I would like to thank Dr. George Antonious for his support. I would also thank my friends Ammar Alzuabade and Emrah Özel for their support. I would also thank Belinda Labadie for her support during lab analysis. Special thanks go to my sponsor, MOHESR (Ministry of Higher Education and Scientific Research) in Iraq for their funding and support during my study period. Finally, I would like to thank my wife, Layla Fadhel, who helped me in my difficult circumstances after we lost everything in my home in Mosul-Iraq city in 2014. iii TABLE OF CONTENTS ACKNOWLEDGMENTS ................................................................................................. iii TABLE OF CONTENTS ............................................................................................... iv LIST OF TABLES ........................................................................................................ vii LIST OF FIGURES ....................................................................................................... ix CHAPTER 1. Introduction ................................................................................................. 1 CHAPTER 2. Can a Spectrophotometer Be Used to Accurately Measure Zingiberene in Tomato Leaf Extracts? ...................................................................................................... 13 2.1 Abstract ............................................................................................................... 13 2.2 Introduction ......................................................................................................... 15 2.3 Materials and Methods ........................................................................................ 21 2.3.1 Plant material ................................................................................................ 21 2.3.2 Gas Chromatography .................................................................................... 22 2.3.3 Spectrophotometry ........................................................................................ 23 2.3.4 Methods