Native Cut Flowers Extending Postharvest Life Using 1-MCP Treatment A report for the Rural Industries Research and Development Corporation by AJ Macnish, DC Joyce, DH Simons and PJ Hofman October 1999 RIRDC Publication No. 99/155 RIRDC Project No. UQ-63A i © 1999 Rural Industries Research and Development Corporation. All rights reserved. ISBN 0 642 57979 2 ISSN 1440-6845 Native Cut Flowers – Extending Postharvest Life Using 1-MCP Treatment Publication no. 99/155 Project no. UQ-63A. The views expressed and the conclusions reached in this publication are those of the author and not necessarily those of persons consulted. RIRDC shall not be responsible in any way whatsoever to any person who relies in whole or in part on the contents of this report. This publication is copyright. However, RIRDC encourages wide dissemination of its research, providing the Corporation is clearly acknowledged. For any other enquiries concerning reproduction, contact the Publications Manager on phone 02 6272 3186. Researcher Contact Details Assoc. Prof. David H. Simons School of Land and Food The University of Queensland Gatton College QLD 4345 Phone: 07 5460 1231 Fax: 07 5460 1455 Email: [email protected] RIRDC Contact Details Rural Industries Research and Development Corporation Level 1, AMA House 42 Macquarie Street BARTON ACT 2600 PO Box 4776 KINGSTON ACT 2604 Phone: 02 6272 4539 Fax: 02 6272 5877 Email: [email protected] Website: http://www.rirdc.gov.au Published in October 1999 Printed on environmentally friendly paper by Canprint ii FOREWORD Postharvest flower fall from various native Australian cut flowers is induced by ethylene. Silver thiosulfate (STS) solution is commonly used to reduce ethylene-induced flower fall, but may be withdrawn from commercial use due to possible environmental hazards. Recently, an alternative and novel gaseous anti-ethylene agent, 1-MCP, was developed. This project aimed to: • Develop dosing (concentration, duration and temperature) relationships for 1-MCP treatment of native cut flowers. • Extend the postharvest longevity of various ethylene-sensitive native cut flowers through treatment with 1-MCP. • Devise and test practical application systems for 1-MCP treatment. This report documents a study into the effects of 1-MCP treatment on a variety of native Australian cut flowers. The effects of 1-MCP concentration, treatment duration and treatment temperature on the ethylene sensitivity of Grevillea ‘Sylvia’ inflorescences were evaluated. A screening study in which the response of a number of native Australian cut flowers to 1-MCP and ethylene treatments is also presented. A detailed investigation into the effects of temperature on the efficacy of 1-MCP treatments on native cut flowers is reported. Finally, several practical application systems for 1-MCP treatment are examined. This report, a new addition to RIRDC’s diverse range of over 400 research publications, forms part of our Wildflowers and Native Plants R&D program, which aims to improve the profitability, productivity and sustainability of the Australian wildflower and native plant industry. Most of our publications are available for viewing, downloading or purchasing online through our website: • downloads at www.rirdc.gov.au/reports/Index.htm • purchases at www.rirdc.gov.au/pub/cat/contents.html Peter Core Managing Director Rural Industries Research and Development Corporation iii ACKNOWLEDGMENTS The authors thank Dr John Faragher of the Victorian Agriculture, Institute for Horticultural Development, Knoxfield laboratory for his interest and collaboration in this study. Special thanks are also due to Tony Slater and Dr David Beardsell for their advice and assistance with experiments conducted at the Knoxfield laboratory. The skilled technical assistance of Victor Roberston, Alison Van Ansem and Srivong Rangsi is gratefully acknowledged. We thank Allan Lisle for his advice on the statistical analysis of data. We acknowledge Setyadjit for his assistance with experiments during the early part of this study. The following people are thanked for provision of cut flowers for experiments: Pamela Barrass, John and Barbara Bradshaw, Edward Bunker, Christensen Flower Wholesaler, Graham and Ester Cook, Jamie Creer, Ben Edwards, Brett Gunderson, David and Olive Hockings, Leo Lynch and Sons (Qld) Pty. Ltd., David Matthews, Dr David Tranter, Philip Watkins and Ken Young. Financial support from the Rural Industries Research and Development Corporation is gratefully acknowledged. In particular, special thanks are due to Dr David Evans for his support throughout this study. iv TABLE OF CONTENTS FOREWORD iii ACKNOWLEDGMENTS iv LIST OF ABBREVIATIONS AND SYMBOLS xii EXECUTIVE SUMMARY xv 1 GENERAL INTRODUCTION 1 1.1 BACKGROUND TO RESEARCH 1 1.2 GENERAL OBJECTIVES 2 1.3 REPORT STRUCTURE 3 2 1-MCP TREATMENT PREVENTS ETHYLENE- INDUCED FLOWER ABSCISSION FROM GREVILLEA ‘SYLVIA’ INFLORESCENCES 5 2.1 INTRODUCTION 5 2.2 MATERIALS AND METHODS 6 2.2.1 Plant Material 6 2.2.2 Chemicals 7 2.2.3 Treatment chambers 8 2.2.4 Treatments 10 2.2.5 Assessments 11 2.2.6 Experiment design and data analysis 13 2.3 RESULTS 15 2.3.1 Effect of 1-MCP concentration on the ethylene sensitivity of G. ‘Sylvia’ inflorescences 15 2.3.2 Effect of 1-MCP pre-treatment duration on ethylene sensitivity of G. ‘Sylvia’ inflorescences 25 2.3.3 Effect of temperature on 1-MCP pre-treatment efficacy 32 2.3.4 Effect of 1-MCP pre-treatment on inflorescence physiology 38 2.4 DISCUSSION 45 3 RESPONSES OF A NUMBER OF NATIVE AUSTRALIAN CUT FLOWERS TO 1-MCP AND ETHYLENE TREATMENTS 51 3.1 INTRODUCTION 51 3.2 MATERIALS AND METHODS 52 3.2.1 Plant material 52 3.2.2 Plant material preparation 56 3.2.3 Chemicals 56 3.2.4 Treatments 57 3.2.5 Assessments 58 3.2.6 Experiment design and data analysis 61 3.3 RESULTS 63 3.3.1 Treatment of a range of native cut flowers with 1-MCP and ethylene 63 3.3.2 Treatment of B. heterophylla with 1-MCP, STS and ethylene 108 3.4 DISCUSSION 116 4 EFFECT OF TEMPERATURE ON THE EFFICACY OF 1-MCP TREATMENT OF CUT FLOWERS 125 v 4.1 INTRODUCTION 125 4.2 MATERIALS AND METHODS 126 4.2.1 Plant material 126 4.2.2 Chemicals 127 4.2.3 Treatments 127 4.2.4 Assessments 128 4.2.5 Experiment design and data analysis 128 4.3 RESULTS 129 4.3.1 Duration of persistence of 1-MCP pre-treatment effects on G. ‘Sylvia’ inflorescences 129 4.3.2 Duration of persistence of 1-MCP and STS pre-treatment effects on flowering C. uncinatum sprigs 135 4.4 DISCUSSION 150 5 COMMERCIAL SCALE 1-MCP TREATMENTS PROTECT GERALDTON WAXFLOWER AGAINST ETHYLENE-INDUCED FLOWER ABSCISSION 153 5.1 INTRODUCTION 153 5.2 MATERIALS AND METHODS 151 5.2.1 Plant material and preparation 151 5.2.2 Chemicals 151 5.2.3 Treatments 151 5.2.4 Quality assessment 158 5.2.5 Experiment design and data analysis 158 5.3 RESULTS 159 5.3.1 Application of 1-MCP inside polyethylene 159 5.3.2 Injection of 1-MCP into cartons 173 5.3.3 Application of 1-MCP into a coolroom 183 5.3.4 Application of 1-MCP in cartons by forced-air cooling 187 5.3.5 Slow release of 1-MCP inside cartons 192 5.4 DISCUSSION 197 6 GENERAL DISCUSSION AND CONCLUSIONS 205 6.1 EFFICACY OF 1-MCP TREATMENTS ON CUT FLOWERS 205 6.2 EFFICACY OF COMMERCIAL SCALE 1-MCP TREATMENTS 206 6.3 EFFECT OF TEMPERATURE ON THE EFFICACY OF 1-MCP TREATMENT 207 6.4 DURATION OF PROTECTION AFFORDED BY 1-MCP TREATMENT 208 6.5 EFFECT OF TEMPERATURE ON THE DURATION OF PROTECTION AFORDED BY 1-MCP TREATMENT 209 6.6 DURATION OF PROTECTION AFFORDED BY STS TREATMENT 209 6.7 GENERAL CONCLUSIONS AND RECOMMENDATIONS 210 APPENDICES 213 APPENDIX A LITERATURE REVIEW 213 vi 1.1 ETHYLENE IN PLANT BIOLOGY 213 1.1.1 General roles 213 1.1.2 Abscission 214 1.1.3 Senescence of vegetative tissue 216 1.1.4 Flower senescence 217 1.1.5 Fruit ripening and senescence 220 1.2 ETHYLENE BIOSYNTHESIS 222 1.3 INHIBITORS OF ETHYLENE BIOSYNTHESIS 224 1.3.1 Aminoethoxyvinylglycine 224 1.3.2 Aminooxyacetic acid 225 1.4 ETHYLENE PERCEPTION 225 1.5 INHIBITORS OF ETHYLENE PERCEPTION 229 1.5.1 Silver ions 229 1.5.2 2,5-Norbornadiene 231 1.5.3 Diazocyclopentadiene 231 1.5.4 Cyclopropenes 233 1.6 INTERACTION BETWEEN ETHYLENE BIOSYNTHESIS AND PERCEPTION 239 1.7 ETHYLENE IN POSTHARVEST HORTICULTURE 241 1.7.1 Gas ripening and degreening 241 1.7.2 Acceleration of deterioration 242 1.7.3 Ethylene removal 242 1.7.4 Biosynthesis inhibition 244 1.7.5 Binding inhibition 244 APPENDIX B SUPPORTING AND STATISTICAL DATA 247 APPENDIX C SUMMARY TABLE OF PROJECT ACHIEVEMENTS 329 BIBLIOGRAPHY 331 vii LIST OF ABBREVIATIONS AND SYMBOLS a.i. active ingredient ACC 1-aminocyclopropane-1-carboxylic acid ACO ACC oxidase ACS ACC synthase Ado-Met S-adenosylmethionine Ag(S2O3)2 silver thiosulfate Ag+ silver AgNO3 silver nitrate ANOVA Analysis of variance AOA aminooxyacetic acid AVG aminoethoxyvinylglycine ca. approximately cf. compare χ2 chi-square cm centimetre Co. company CO2 carbon dioxide Co2+ cobalt ions CP cyclopropene CRD completely randomised design DACP diazocyclopentadiene oC degrees celsius DI deionised water DICA dichloroisocyanurate 3,3-DMCP 3,3-dimethylcyclopropene E east e.g. for example epi epinastic et al. and others FID flame ionisation detector FW fresh weight ggram > greater than ≥ greater than or equal to HCl Hydrochloric acid hr hour i.e. that is viii IHD Institute for Horticultural Development Inc. Incorporated kd binding dissociation constant kg kilogram (103 g) km kilometre KMnO4 potassium permanganate KOH potassium hydroxide < less than L litre LSD least significant difference 1-MCP 1-methylcyclopropene mmetre M molar (moles/L) MACC 1-(malonylamino) cyclopropane-1-carboxylic acid µL microlitre (10-6 L) mg milligram (10-3 g) mL millilitre (10-3 L) mm millimetre mM millimolar (10-3 M) mol mole mRNA messenger RNA MTA methylthioadenosine MTR methylthioribose n number of replicates NaOH sodium hydroxide Na2S2O3 sodium thiosulfate NH4SO4 ammonium sulphate nL nanolitre (10-9 L) nmol nanomole (10-9 mole) nor non-ripening Nr never-ripe 2,5-NBD 2,5-norbornadiene ns not significant NSW New South Wales % percent ± plus or minus P probability pers.