Background on “A Global Conservation Strategy for Cassava and Wild Manihot Species” • Dr. Clair H. Hershey of Cornell University, acting as a consultant for the International Center for Tropical Agriculture (CIAT), facilitated the process of developing the cassava strategy “A Global Conservation Strategy for Cassava and Wild Manihot Species”. • A survey of collections, content and status of conservation was distributed to curators in early 2008. A meeting of the key experts and curators, held at CIAT headquarters in Cali, Colombia, took place from 30 April to 2 May 2008. Coordinators: Dr Clair H. Hershey, consultant for CIAT: [email protected] Dr Daniel Debouck, CIAT, Colombia: [email protected] A Global Conservation Strategy for Cassava (Manihot esculenta) and Wild Manihot Species1 December 2010 1 Prepared by Clair H Hershey ([email protected]), consultant to CIAT. A summary of stakeholder deliberations and recommendations. Contents Disclaimer............................................................................................................................................... 4 Executive Summary................................................................................................................................ 4 1 Introduction and background to the strategy ....................................................................................... 8 1.1 Goals and outputs ................................................................................................................................8 1.2 Building on progress, meeting new challenges ...................................................................................8 1.3 Precedents and resources ...................................................................................................................11 1.4 Sources of information ......................................................................................................................13 2 Cassava in the global economy and agro-ecosystem......................................................................... 14 2.1 Manihot species overview and the origins of cassava.......................................................................14 2.2 Production overview..........................................................................................................................16 2.3 Evolution and farmer selection..........................................................................................................25 2.4 Modern genetic improvement............................................................................................................25 2.5 Landraces and wild species at risk ....................................................................................................26 3 Cassava-related networks .................................................................................................................. 27 4 Cassava in the regional crop strategies.............................................................................................. 28 4.1 Americas............................................................................................................................................28 4.2 Eastern Africa....................................................................................................................................28 4.3 SADC Region....................................................................................................................................29 4.4 South and Southeast Asia ..................................................................................................................29 4.5 Pacific Islands....................................................................................................................................30 4.6 Summary from the regional reports...................................................................................................30 5 Overview of cassava collection and conservation............................................................................. 31 5.1 Collecting strategies, techniques and priorities .................................................................................31 5.2 Conservation alternatives for cassava................................................................................................33 5.2.1 Field..............................................................................................................................................................34 5.2.2 In vitro..........................................................................................................................................................35 5.2.3 Cryopreservation ..........................................................................................................................................35 5.2.4 Seed ..............................................................................................................................................................36 5.2.5 Pollen............................................................................................................................................................37 5.3 Conservation costs.............................................................................................................................37 6 Overview of wild Manihot species collection and conservation....................................................... 38 7 Overview of current cassava genebanks............................................................................................ 39 7.1 Genebank holdings of landrace varieties and collection needs .........................................................39 7.2 Collaboration arrangements in conservation .....................................................................................41 7.3 The most important collections .........................................................................................................42 8 Overview of current wild Manihot species genebanks...................................................................... 43 9 Improving the efficiency of conservation.......................................................................................... 52 9.1 Core collections .................................................................................................................................52 9.2 Duplicate identification .....................................................................................................................53 9.3 Improved slow-growth conditions.....................................................................................................53 10 Characterization and preliminary evaluation................................................................................... 54 11 Distribution...................................................................................................................................... 55 11.1 Benefits and risks.............................................................................................................................55 11.2 Forms of exchange...........................................................................................................................55 11.2.1 Vegetative ..................................................................................................................................................55 11.2.2 Seeds ..........................................................................................................................................................56 11.3 Quarantine considerations ...............................................................................................................56 11.4 Procedures for distribution ..............................................................................................................58 11.4.1 Sources .......................................................................................................................................................58 2 Cassava Conservation Strategy 11.4.2 Legal aspects ..............................................................................................................................................58 12 Documentation of germplasm management.................................................................................... 59 13 Rationalizing a conservation strategy – Manihot esculenta ............................................................ 59 13.1 Elements of a conservation strategy ................................................................................................59 13.2 Conservation scenarios....................................................................................................................60 13.3 A consensus strategy: collaborative centralization..........................................................................62 13.4 Implementation and funding............................................................................................................63 14 Rationalizing a conservation strategy – Manihot wild species........................................................ 65 Appendix I. Workshop program........................................................................................................... 67 Appendix II. Workshop list of presenters and participants .................................................................. 71 Appendix III. Cassava and wild Manihot survey form .......................................................................