Handbooks for Genebanks No. 8 Manual of Seed Handling in Genebanks N. Kameswara Rao, Jean Hanson, M. Ehsan Dulloo, Kakoli Ghosh, David Nowell and Michael Larinde Handbooks for Genebanks No. 8 Manual of Seed Handling in Genebanks N. Kameswara Rao¹, Jean Hanson², M. Ehsan Dulloo¹, Kakoli Ghosh³, David Nowell³ and Michael Larinde³ ¹ Bioversity International Via del Tre Denari 472a, 00057 Maccarese, Rome, Italy ² International Livestock Research Institute (ILRI) P.O. Box 5689, Addis Ababa, Ethiopia ³ Food and Agriculture Organization of the United Nations (FAO) Via delle Terme di Caracalla, 00100 Rome, Italy Handbooks for Genebanks No. 8 Bioversity International is an independent international scientific organization that seeks to improve the well-being of present and future generations of people by enhancing conservation and the deployment of agricultural biodiversity on farms and in forests. It is one of 15 centres supported by the Consultative Group on International Agricultural Research (CGIAR), an association of public and private members who support efforts to mobilize cutting-edge science to reduce hunger and poverty, improve human nutrition and health, and protect the environment. Bioversity has its headquarters in Maccarese, near Rome, Italy, with offices in more than 20 other countries worldwide. The Institute operates through four programmes: Diversity for Livelihoods, Understanding and Managing Biodiversity, Global Partnerships, and Commodities for Livelihoods. The international status of Bioversity is conferred under an Establishment Agreement which, by January 2006, had been signed by the Governments of Algeria, Australia, Belgium, Benin, Bolivia, Brazil, Burkina Faso, Cameroon, Chile, China, Congo, Costa Rica, Côte d’Ivoire, Cyprus, Czech Republic, Denmark, Ecuador, Egypt, Greece, Guinea, Hungary, India, Indonesia, Iran, Israel, Italy, Jordan, Kenya, Malaysia, Mali, Mauritania, Morocco, Norway, Pakistan, Panama, Peru, Poland, Portugal, Romania, Russia, Senegal, Slovakia, Sudan, Switzerland, Syria, Tunisia, Turkey, Uganda and Ukraine. Financial support for Bioversity’s research is provided by more than 150 donors, including governments, private foundations and international organizations. For details of donors and research activities please see Bioversity’s Annual Reports, which are available in printed form on request from [email protected] or from Bioversity’s Web site (www.bioversityinternational.org). The geographical designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of Bioversity or the CGIAR concerning the legal status of any country, territory, city or area or its authorities, or concerning the delimitation of its frontiers or boundaries. Similarly, the views expressed are those of the authors and do not necessarily reflect the views of these organizations. Mention of a proprietary name does not constitute endorsement of the product and is given only for information. Citation : Rao NK, Hanson J, Dulloo ME, Ghosh K, Nowell D and Larinde M. 2006. Manual of seed handling in genebanks. Handbooks for Genebanks No. 8. Bioversity International, Rome, Italy. ISBN 978-92-9043-740-6 Bioversity International Via dei Tre Denari, 472/a 00057 Maccarese Rome, Italy © Bioversity International, 2006 ii Manual of Seed Handling TABLE OF CONTENTS Acknowledgments vi Partners in this publication vii List of reviewers ix Foreword x Preface xii 1. Introduction 1 2. Germplasm acquisition and registration 5 2.1 Germplasm acquisition 5 2.2 Germplasm registration 13 3. Seed cleaning 20 4. Seed moisture content determination and drying 28 4.1 Seed moisture content determination 28 4.2 Seed drying 36 5. Seed quality testing 50 5.1 Seed viability testing 50 5.2 Seed health testing 77 5.3 Seed testing for inadvertent introduction of transgenes 82 6. Seed packaging and storage 86 6.1 Seed packaging 86 6.2 Seed storage 91 7. Germplasm distribution 96 8. Germplasm monitoring and regeneration 103 8.1 Germplasm monitoring 103 8.2 Germplasm regeneration 108 Annex I: International policies and frameworks influencing access to and exchange of germplasm 118 Annex II: Serological methods for detecting plant pathogens 121 Annex III: Glossary 123 Annex IV: Specialized equipment for seed genebanks 130 Annex V: List of acronyms 147 iii Handbooks for Genebanks No. 8 FLOWCHARTS Flowchart 1.1. General sequence of operations in a seed genebank 3 Flowchart 2.1. Germplasm registration 14 Flowchart 3.1. Seed cleaning 21 Flowchart 4.1. Seed moisture content determination 29 Flowchart 4.2. Seed drying 37 Flowchart 4.3. Protocol to determine seed storage behaviour 42 Flowchart 5.1. Germination testing 52 Flowchart 6.1. Seed packaging 87 Flowchart 7.1. Germplasm distribution 97 Flowchart 8.1. Viability monitoring 105 TABLES Table 4.1. Suggested method of moisture determination for important crop and forage species (ISTA, 2005) 30 Table 4.2. Species for which grinding is obligatory (ISTA, 2005) 32 Table 4.3. Recording and calculation of seed moisture content 33 Table 4.4. Equilibrium moisture contents (approximate) of some common crop seeds at 25°C 39 Table 5.1. Guidelines for testing germination of the most common crop species Refer to ISTA (2005) or AOSA (2005) for information on other crops 53 Table 5.2. Model data sheet to record germination results 70 Table 5.3. Concentration, temperatures and period of staining with tetrazolium solution (for Annex I crops of the International Treaty on PGRFA) 75 Table 6.1. Model table for recoding information on seed packaging 90 Table 6.2. Suggested storage temperature and moisture content for active collections (source: Bioversity International, unpublished) 92 Table 8.1. Suggested interval for monitoring germination of active or base collections in oily and non-oily seeds 106 Table 8.2. Threshold germination percentages for regeneration of accessions 106 Table 8.3. Sequential germination test plan for 85% regeneration standard when testing seeds for germination in groups of 40 107 Table 8.4. Reproductive behaviour and pollination control mechanisms for regeneration of important crops 116 iv Manual of Seed Handling FIGURES Figure 2.1. Seed extraction from fleshy fruits 9 Figure 4.1. Moisture isotherms 39 Figure 4.2. Predicting drying time 41 Figure 5.1. Seed germination testing on top of absorbent paper in Petri dishes 60 Figure 5.2. Seed germination testing by between-paper method 62 Figure 5.3. Seed germination testing in sand 64 Figure 5.4. Seedling abnormalities in pea 66 Figure 5.5. Seedling abnormalities in groundnut 67 Figure 5.6. Seedling abnormalities in wheat 68 Figure 5.7. Seedling abnormalities in onion 69 Figure 5.8. Manual scarification of seed coat 71 Figure 5.9. Staining pattern after tetrazolium test in dicot seeds 76 Figure 5.10. Staining pattern after tetrazolium test in monocot seeds 77 BOXES Box 2.1. Base unit for registration 17 Box 4.1. Options for initial drying 45 Box 5.1. Humidification of dry seeds 56 Box 5.2. Seedling defects classified as abnormal 65 v Handbooks for Genebanks No. 8 ACKNOWLEDGEMENTS We are especially grateful to T. van Hintum, L. de Groot, L. Boukema, A. Borner, S. Linington, C.N. Nkhoma, L.M. Engle, N.C. Altoveros, M. Mackey, A.W. Ebert, Xiaorong Hu, M. Wetzel, V. Mahalakshmi, H. Kamau and W. Marandu for their critical review of the first draft of the manuscript. We acknowledge the help received from Teodardo Calles in constructing the flowcharts. The financial support received from the Technical Centre for Agricultural and Rural Cooperation ACP-EU (CTA), The Netherlands, for publication of this manual is gratefully acknowledged. Thanks are also due to Tran Hong of the University of Reading for his expert advice on some of the technical issues covered in this guidebook. We also thank all Bioversity International staff, especially Annie Huie, who assisted in the preparation of this manual and Hope Traficanti, who provided English editing. We thank Nicolas Muema for the illustration drawings. We are very grateful to Elizabeth Goldberg, Head of Bioversity International’s Capacity Development Research and Support Unit, for her guidance in the development of the manual and its self-learning version. Credit is also due to Paul Neate and his team, particularly Patrizia Tazza and Frances Ferraiuolo, for the design and style of this publication. A NOTE TO READERS Bioversity International’s Handbooks for Genebanks are intended to provide practical information to genebank curators and others working in genebanks. To facilitate their use their binding allows them to be kept open on a desk or bench, while the wide margins and ‘Notes’ pages provide space for readers to make notes or annotate the text. Bioversity welcomes feedback from readers on the content and format of the handbook for possible future revisions. vi Manual of Seed Handling PARTNERS IN THIS PUBLICATION The International Livestock Research Institute (ILRI) works at the crossroads of livestock and poverty, bringing high-quality science and capacity-building to bear on poverty reduction and sustainable development. ILRI is a non-profit-making organization with headquarters in Nairobi, Kenya, conducting research in Africa, Asia and Latin America and the Caribbean, with offices in East, West and Southern Africa, South and Southeast Asia, China and Central America. As one of the 15 Future Harvest centres of the Consultative Group on International Agricultural Research (CGIAR), ILRI’s strategy focuses on three livestock-