New Hybrid Leucadendrons A report for the Rural Industries Research and Development Corporation By Guijun Yan, Ben Croxford and Ralph Sedgley July 2001 RIRDC Publication No 01/099 RIRDC Project No UWA 46A © 2000 Rural Industries Research and Development Corporation. All rights reserved. ISBN 0 642 58321 8 ISSN 1440-6845 New Hybrd Leucadendrons Publication No. 01/099 Project No. UWA 46A 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 Dr Guijun Yan Plant Sciences Faculty of Agriculture The University of Western Australia Nedlands, WA 6009 Phone: (08) 9380 1240 Fax: (08) 9380 1108 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 July 2001 Printed on environmentally friendly paper by Canprint ii Foreword There are many outstanding species and varieties in the genus Leucadendron, which are important in Australian floriculture industry for its export market. Recent data shows that Leucadendrons are a major export group to Japan, comprising 12.8% of Australian imports, third after Waxflowers and Kangaroo Paws. The beautiful flowers of Leucadendrons and the muted green leaves, tinted with other soft shades, provide a perfect counterpoint as fillers in flower arrangement. However, lacking of new varieties has become a more and more obvious factor hindering the further development of the industry. This project is intending to enhance the economic strength of the Australian floriculture industry by assuring the supply of new Leucadendron cultivars through interspecific hybridisation and, to facilitate this process, by understanding the reproductive biology underlying the breeding of this genus. The objective of this project is to extend the continuity of supply of Leucadendron as cut flowers and to capture a greater share of markets by extending the flowering period to fill in the niches. Outstanding results have been achieved in this project. Through the development of pollen storage, seed germination and genome investigation techniques, a successful breeding protocol for Leucadendron has been developed. Following this protocol, more than 500 different cross combinations from 140 genotypes of 27 species have been attempted. This has resulted in about 20,000 hybrid seeds. Our germination and early selection results so far suggest that most of these seeds are both viable and true hybrids as they share characteristics from both parents. Altogether, 3,122 hybrid plants have been planted on growers’ properties and are currently being assessed for their cut flower potential. It is hoped that several new varieties will be selected from these hybrids and will be released to the wildflower industry in the very near future. This publication considers the breeding process of Leucadendron with special emphases on hybridisation, selection, reproductive biology, pollen collection and storage, seed treatment and germination, pollen pistil interaction and chromosomes assessment of Leucadendron. We suggest that the information contained in this report can be useful for wildflower growers to develop their own breeding programs. This project was funded from RIRDC Core Funds which are provided by the Federal Government. This report, a new addition to RIRDC’s diverse range of over 600 research publications, forms part of our Wildflowers and Native Plants R&D program, which aims to identify and develop new fresh products. 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/eshop Peter Core Managing Director Rural Industries Research and Development Corporation iii Acknowledgements We would like to express our sincere gratitude to the Protea growers for both their financial support and their continuing help and enthusiasm in gathering genetic resources and trialling of hybrids produced from this project. The contributing Protea growers in alphabetical order are: Abbey Farm – Paul Cook and Cheryl Foster Amarillo Protea - Ralph and Grace Sedgley Annie Brook Flower Farm - Wally and Dawn Lewis Busselton Proteas - John Daykin Cox Farm - Morris and Miriam Cox Tan Ridge - Tom and Joan Anthoine Other Protea Growers whose contribution has been appreciated include: Coastal Flora - Peter Cornock and Phil and Jo Purely Proteas – Graham and Aileen Twaddle Jo Reid We would also like to thank Mr Fucheng Shan for the scientific and technical support to this project. iv Abbreviations BAP 6-benzylaminopurine °C degrees Celsius DNA deoxyribose nucleic acid F1 first generation hybrid F2 second generation hybrid FDA Fluorescein diacetate g/L grams per litre H2O2 hydrogen peroxide Mmolar mL millilitre mm millimetre µM micromolar MS mixture of salts as per Murashige and Skoog (1962) n.a. not applicable NaOH sodium hydroxide PCB para-dichlorobenzene pers. comm. personal communication UWA The University of Western Australia w/v weight by volume x basic ploidy number 2n somatic ploidy number 2x diploid v Contents FOREWORD.......................................................................................................................................III ACKNOWLEDGEMENTS................................................................................................................IV ABBREVIATIONS .............................................................................................................................. V CONTENTS.........................................................................................................................................VI EXECUTIVE SUMMARY..............................................................................................................VIII 1. CROSSING AND HYBRIDS ........................................................................................................... 1 1.1 INTRODUCTION .............................................................................................................................. 1 1.2 OBJECTIVES .................................................................................................................................. 2 1.3 MATERIALS AND METHODS ......................................................................................................... 3 1.3.1 Selection of Parents................................................................................................................ 3 1.3.2 Pollen Collection.................................................................................................................... 3 1.3.3 Isolation of female flowers ..................................................................................................... 4 1.3.4 Cone and Seed Collection ...................................................................................................... 4 1.3.5 Seed Germination................................................................................................................... 5 1.4 RESULTS ....................................................................................................................................... 6 1.4.1 Selection of Parents................................................................................................................ 6 1.4.2 Pollen collection..................................................................................................................... 8 1.4.3 Isolation of female flowers ..................................................................................................... 9 1.4.4 Cone and Seed Collection ...................................................................................................... 9 1.4.5 Seed Germination................................................................................................................. 11 1.5 DISCUSSION ................................................................................................................................13 1.5.1 Leucadendron Breeding methodology.................................................................................. 13 1.5.2 Selection of parents and their ability to form hybrids.......................................................... 15 1.5.3 Improving the range of Leucadendron varieties .................................................................. 16 1.5.4 Initiation of a long term Leucadendron breeding program. ................................................ 17 1.6 REFERENCE................................................................................................................................. 17 2. ASSESSMENT OF HYBRIDS....................................................................................................... 18 2.1 INTRODUCTION ........................................................................................................................... 18 2.2 OBJECTIVES