INDUCTION OF LINEAR FURANOCOUMARINS IN CELERY, APIUM GRAVEOLENS BY INSECT DAMAGE AND THElR EFFECTS ON LYGUS LINEOLARIS AND THE PARASITOID PERSITENUS STYGICUS. Pmsented to The Faculty of Graduate Studies of The University of Guelph by DIANE E. STANLEY-HORN In partial fulfillment of requirements for the degree of Master of Science June, 1999 <O Diane E. Stanley-Hom, 1999 National Library Bibliothèque nationale du Canada Acquisitions and Acquisitions et Bibliographie Services services bibliographiques 395 Wellington Street 395, rue Wellingtori ûttawa ON KIA ON4 OnawaON KlAON4 Canada Canada The author has granted a non- L'auteur a accordé une licence non exclusive licence allowing the exclusive permettant à la National Library of Canada to Bibliothèque nationale du Canada de reproduce, loan, distriiute or seU reproduire, prêter, distribuer ou copies of this thesis in microform, vendre des copies de cette thèse sous paper or electronic formats. la forme de microfiche/nlm, de reproduction sur papier ou sur format électronique. The author retains ownership of the L'auteur conserve la propriete du copyright in this thesis. Neither the droit d'auteur qui protège cette thèse. thesis nor substantial extracts fkom it Ni la thèse ni des extraits substantiels may be printed or otherwise de celle-ci ne doivent être imprimés reproduced without the author's ou autrement reproduits sans son permission. autorisation. ABSTRACT INDUCTION OF LINEAR FURANOCOUMARINS IN CELERY, APUM GRAVEOLEUS BY INSECT DAMAGE AND THElR EFFECTS ON LYGUS LINEOURIS AND THE PARASITOID PERlSTENUS SWGICUSa Diane E. Stanley-Hom Advisor: University of Guelph Professor M, K, Sears Celery, Apium graveolens, produces three phototoxic linear furanocoumarins (LFCs) that can cause a photoàennatitic reactian in humans in the presence of UV radiation. LFCs are toxic to numerous organisms and are both constituüvely produced and induœd in response to several abiotic and biotic stresses. Induction of LFCs by the tamished plant bug, Lygus lineolans UPB) and the cabbage looper, Tnchoplusia ni, and effects of LFCs on growth and development of TPB and the parasitoid Pemitenus stygicus were examined. 60th insects induced LFCs in celery, but concentrations in petioles rarely reached levels capable of causing photodermatitis. Developmental rates of TPB were affected by ingestion of LFC-containing diet. However, other factors are likely to accaunt for the difierences obsewed between nymphs fed damaged and undarnaged celery tissue. The data suggest that other compounds in celery petioles may be of value to breeding programs involved in the development of insect-resistant genotypes. Acknowledgements Iwould like to express my appreciation to the following people for their support and encouragement during the fuffillment of my degree. First, 1 would Iike to thank Dr. Mark Sears for al1 of the advice and encouragement throughout this project and for always providing me with an alternative perspective. I would also like to thank Drs. Geny Stephenson and Rick Yada for their thoughtful advice and enthusiasm for my research. I am also grateful to the Ontario govemment for their financial support through an Ontario Graduate Scholarship. The completion of this project would not have been possible without the assistance of Linda Veldhuis, who willingly and patiently helped me battle the sometimes 'ternperamental' HPLC apparatus and to Marg Carter for her cornputer expertise. I would also like to thank al1 of my wonderful friends who made my experience at the University of Guelph so much fun: Simon Lachance, Traœy Baute. Kurt Randall. Sarah Butler, Claudia Sheedy, Sarah Rosloski, Laura VanEerd and the rest of the EVB gang. Finally. want to acknowledge my wondefil husband Greg for his love. patience and encouragement and my ever-supportive farnily. TABLE OF CON7ENTS .... Page Acknowledgements ................................................................m..m....i Table of contents ...........................................................................ii List of tables .................................................................................. iv List of figures .......................................................m...............m.m.....mmv List of appendices ...........................................................................vi Literature review ....................................m........................................1 1. 1 Introduction........................................................................ 1 1.2 Toxicity of LFCs in humans ................................................... -2 1.3 Biosynthesis of LFCs ........................................................... 3 1.4 Distribution of LFCs in Plants................................................ 6 1.5 LFCs as Inducible Resistance Factors ................................. 10 1-51 Interactions with Pathogens.......................................... 11 1.52 Interactions wifh lnsects .............................................. 12 1-6 Tritrop hic lnteractions ....................................................... 16 1.7 The Celery-Pest Complex in Ontario .................................... 17 1-71 The tamished plant bug, Lygus lineolaris (P . de B.) ............ 17 1-72 The ca bbage looper. Trichoplusia ni(Hu bner) .................. 21 Chapter 2: Induction of three phototoxic linear furanocoumarins celery. Apium graveolens L., in response to insect feeding damage 2.1 Abstract .......................................................................... 25 2.2 Introduction ........................... ,.._. ............................ 26 2.3 Objectives ....................................................................... 29 2.4 Materials and Methods ........................... .. ............ 30 2.41 Plant and insect sources .............................................. 30 2.42 Extraction and Analysis of LFCs .................................... 31 2.43 Experimental set-up ......................... .. ................... 34 2.44 Statistical analysis ...................................................... 38 2.5 Results ........................................................................... 38 2.51 Expt. 1 LFC induction in celery leaves by cabbage looper larvae ................................................... 38 2.52 Expt. 2 LFC induction in celery petioles by cabbage looper larvae ................................................... 39 2.53 Expt. 3 LFC induction in œbry leaves by TPB adub .................................................................. 39 2.54 Expt .4 LFC induction in celery petioles by TPB adults ................................................................. -41 2.55 Expt. 5 A wmparison of indudion in celery petioles between TPB adults and nymphs .................45 2.56 Expt .6 TPBinduced LFC production in fieldgrorni plants .......................................................... 47 2.57 Expt. 7 Duration and extent of LFC induction following mechanical damage ............................ 50 2.6 Summary of Results ......................................................... 53 2.7 Discussion ...................................................................... 54 2.8 Recommendations for future research ................................. ..61 Chapter 3: An assessrnent of the impact of three phototoxic linear furanocoumarins in Apium gmveolens on growth and development of the parasitised and nort-pansitised nymphs of the tarnished ppkt bug (TPB). Lygw lineolaris (Palisot de Beauvob) 3.1 Abstract .......................................................................... 62 3.2 Introduction ..................................................................... 63 3.3 Objedive ........................................................................ 66 3.4 Materials and Methods .................... .. ........................... 67 3.41 Plant and diet sources ............................................ -67 3.42 lnsect sources ...................................................... -68 3.43 Extradion and Analysis of LFCs .............................. 69 3.44 Measurement of Growth Parameters......................... 71 3.45 Experimental set-up ............................................... 72 3.46 Statistical Analysis ................................................. 74 3.5 Results ........................................................................... 74 3.51 Expt 1 Growth and development of parasitised and nonparaslised TPB fed damaged and undamaged celery tissue ..................... 74 3.52 Expt. 2 Growth and development of parasitised and nonparasitised TPB on celery leaves, petioles and artificial diet containing LFCs ...... 77 3.53 Expt. 3 Growth and development of parasitised and nonparasitised TPB fed a semi-solid artificial diet containing LFCs ......................... 82 3.6 Summary of Results ......................................................... 84 3.7 Discussion ...................................................................... 85 3.8 Recommendations for Future Research ................................. 91 Literature cited ...................m..mmmmmmmm ................................. ..92 iii LIST OF TABLES Table 1. Mean weights (mg) of tamished plant bug nymphs fed a Iiquid artificial diet containhg various concentrations of LFCs ..................81 Table 2. Mean weights of tarnished plant bug nymphs fed a semi-solid artificial diet containing various concentrations of LFCs ................83 Figure 1. Chernical structure of four linear furanocoumarins in