dColin Khoury1,2,3, Nora Patricia Castaeda Alvarez1,4,5, Holly Vincent5, Andy Jarvis1,6, Nigel Maxted5, Ruth Eastwood7, Julin Ramrez-Villegas1,6,8& Luigi Guarino21Decision and Policy Analysis Program, International Center for Tropical Agriculture (CIAT), Cali, Colombia, email: c.khoury@cgiar.org; 2Global Crop Diversity Trust, Rome, Italy; 3C. T. de Wit Graduate School Production Ecology & Resource Conservation, Wageningen University, Wageningen, the Netherlands; 4Bioversity International, Regional Office for the Americas, Cali, Colombia; 5School of

Biosciences, University Of Birmingham, Birmingham, UK; 6CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS), Cali, Colombia; 7Millennium Seed Bank Partnership, Seed Conservation Department, Royal Botanic Gardens, Kew, West Sussex, UK, 8School of Earth and Environment, University of Leeds, Leeds, UK

Planning for Collecting the Crop Wild Relatives of the Worlds Major Crops

IntroductionThe wild plant species related to the worlds major crops are playing an ever-increasing role in providing traits of value to crop improvement programs, as techniques for utilization improve and as breeders survey ever-wider diversity in order to increase agricultural production. Adaptation of agriculture to the more variable and extreme climates of the future is likely to rely in part upon the genetic resources found within these crop wild relatives (CWR). Like many plant species, CWR are exposed to increasing pressures from habitat modification, and climate change is projected to further stress populations in many areas. As the representation of CWR diversity in ex situ conservation (genebanks) is far from comprehensive (e.g. only 6% of European CWR species are represented in gene banks1), the genetic resources that are vitally important for crop adaptation are in danger of being lost. It is increasingly feasible to formulate a global plan for the collection of CWR diversity due to 1) the taxonomic and genetic relationships between species increasingly clarified, 2) ease of access to large on-line ecogeographic data resources, 3) better knowledge and tools for modelling and mapping the distribution of plant species through Geographic Information Systems (GIS), and 4) implementation of the International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGRFA) which promotes international collection and conservation efforts. We document the progress to date on planning for a major new global initiative for the collection and conservation of CWR, the results and products of which will be available to the global community.

Compiling an inventory of CWR taxa worldwideWe compiled a list of the worlds major crops from Annex 1 of the ITPGRFA2, and the major and minor crops listed in Appendix 2 of the World Atlas of Biodiversity3. Approximately 10,500 CWR species are found in the same genera as the crops included in the compiled list1. Narrowing the focus to the closely related taxa with the highest potential to contribute to crop improvement, utilizing gene pool or taxon group concepts4, approximately 1,100 CWR species from 102 genera (Table 1) are given priority.

Table 1: Genera of Priority Crops

Determining CWR taxa distributions and conservation gapsWe utilize a systematic gap analysis method5 aimed at identifying locations of genetic diversity un- or under- secured in conservation systems, in order to inform planning of germplasm collecting for ex situ conservation (Figure 1). We are gathering and geo-referencing species occurrence and conservation data from online resources, herbarium and genebank databases, and in collaboration with researchers. The distributions of germplasm accessions will be compared to GIS-modeled taxon distributions in order to identify gaps in ex situ conservation coverage. Results will form the basis for a prioritization of taxa within genepools, and the identification of priority locations, for efficient collecting (Figure 2). Early versions of the analysis for 12 crop genepools are available6. Combined results for all genepools will facilitate the identification of regions (plant genetic resource gap megacenters) prioritized for the efficient and effective collecting of CWR diversity on a global scale.

Improving the state of conservation of CWR in genebanksWild species conserved in genebanks often lack species-specific germination protocols based upon knowledge of physiological heterogeneity and dormancy mechanisms. The Millennium Seed Bank (MSB), of Royal Botanic Gardens, Kew, is working to test accession viability and refine germination protocols for CWR in order to strengthen capacity for their conservation, especially in developing countries. Germination protocols will be published on the Seed Information Database7.

Looking ahead- collecting, conserving, and using CWRThe global inventory of CWR taxa, the gap analysis methods and results, and the germination protocols will be published and made freely available online for the use of the global community as conservation tools. Results of these analyses will form the basis for strategies for the collection of priority CWR populations worldwide, in collaboration with national and international research centers and other partners.

Collected CWR accessions will be stored in relevant national and international genebanks and at the MSB, and will be safety duplicated for long-term security at the Svalbard Global Seed Vault. Following collection, traits of value for adaptation to climate change will be transferred into cultivated lines through pre-breeding, and the results will be evaluated in the field. The wild species accessions and the promising lines generated will be collected and made available to the global community for breeding and research under the terms of the ITPGRFA.

Collaborate with us!The gap analysis method is dependent upon the quality of data utilized. Important species occurrence data are not easily available online, and ecogeographic datasets benefit significantly from expert review. We would therefore like to ask for your collaboration in sharing with the project occurrence and conservation data on the priority genera. If you have expertise in the taxonomic and genetic relationships within the genepools, or in the distribution and/or conservation status of taxa, we would appreciate your inputs for validating the results of the taxonomic work and the gap analyses. Please contact us at c.khoury@cgiar.org.

References

1Maxted N and Kell SP (2009) Establishment of a global network for the in situ conservation of crop wild relatives: status and needs. FAO Consultancy Report, pp. 1-265. FAO, Rome.

2FAO (2001) International Treaty on Plant Genetic Resources for Food and Agriculture. Food and Agriculture Organization of the United Nations, Rome, Italy.

3Groombridge B and Jenkins MD (2002) World Atlas of Biodiversity. Prepared by the UNEP World Conservation Monitoring Centre. University of California Press, Berkeley, California.

4Maxted N, Ford-Lloyd BV, Jury SL, Kell SP and Scholten MA (2006) Towards a definition of a crop wild relative. Biodiversity and Conservation 15(8): 26732685.

5Ramrez-Villegas J, Khoury C, Jarvis A, Debouck DG and Guarino L (2010) A Gap Analysis Methodology for Collecting Crop Genepools: A Case Study with Phaseolus Beans. PLoS ONE 5(10), e13497.

6Bioversity International, IRRI, and CIAT (2009) Gap analysis. Available online at: http://gisweb.ciat.cgiar.org/GapAnalysis/.

7Kew Royal Botanic Gardens (2011) Seed Information Database. Available online at: http://data.kew.org/sid/sidsearch.html.

CWR photos from Okogbenin E (2010) The Use and Challenges of CWR in Breeding. Presentation for Adapting Agriculture to Climate Change: The Need for Crop Wild Relatives, Bellagio, 7-9 September 2010.

Acknowledgments Financial support for the planning for a global collecting and conservation project for CWR comes from the Norwegian Ministry of Foreign Affairs. The project is managed by the Global Crop Diversity Trust, in collaboration with the Royal Botanic Gardens, Kew.

Agropyron Colocasia Ipomoea Pistacia

Allium Corylus Isatis Pisum (incl. Vavilovia)

Ananas Crambe Juglans Prunus

Arachis Cucumis Lablab Pyrus

Armoracia Cucurbita Lactuca Raphanus (incl. Raphanobrassica)

Artocarpus Cynara Lathyrus Ribes

Asparagus Daucus Lens Rorippa

Avena Digitaria Lepidium Saccarhum

Barbarea Dioscorea Lupinus Secale

Bertholletia Diplotaxis Malus Sesamum

Beta Echinochloa Mangifera Setaria

Brassica Elaeis Manihot Sinapis

Cajanus Elettaria Medicago Solanum (incl. Lycopersicon)

Camellia Eleusine Musa (incl. Ensete) Sorghum

Capsicum Elymus Olea Spinacia

Carica Eruca Oryza Theobroma

Carthamnus Ficus Panicum Triticum (incl. Triticosecale, Aegilops, others)

Chenopodium Fragaria (incl. as Potentilla) Pennisetum Vicia

Cicer Glycine Persea Vigna

Citrullus Gossypium Phaseolus Vitellaria

Citrus (incl. Fortunella and Poncirus) Helianthus Phoenix Vitis

Cocos Hordeum Pimenta Xanthosoma

Coffea Ilex Piper Zea (incl. Tripsacum)

Taxon richness in Phaseolus Gap richness in Phaseolus

Svalbard Global Seed VaultIRRI

ICRISAT

Manihot glaziovii-cassava mosaic disease resistance

Musa acuminata-black sigatoga resistance

Aegilops tauschii- hessian fly resistance

Useful CWR

Figure 1: Gap Analysis Method

Figure 2: Gap Analysis Results