This document outlines initial steps toward developing a national conservation strategy for crop wild relatives (CWR) in the United States. It describes prioritizing CWR taxa based on their potential use value for crop improvement. A list of priority crops and genera was compiled. Over 3,000 native and non-native CWR and economically important wild taxa occurring in the US were inventoried. Gap analyses will identify locations of underrepresented genetic diversity to inform germplasm collecting and in situ conservation planning. The results will prioritize taxa and locations for efficient CWR conservation.

1. d
Initial Steps toward a National Conservation Strategy
for Crop Wild Relatives of the United States
Colin Khoury1,2, Stephanie Greene3, Nora Patricia Castañeda Alvarez1,4
1Decision and Policy Analysis Program, International Center for Tropical Agriculture (CIAT), Cali, Colombia email: c.khoury@cgiar.org; 2C. T. de Wit Graduate School Production Ecology & Resource Conservation, Wageningen University, Wageningen, The Netherlands; 3USDA ARS, Prosser, WA, USA; 4Bioversity International, Regional Office for the Americas, Cali, Colombia
Introduction Prioritizing genepools based on potential use value Next steps toward a national CWR conservation strategy
The wild relatives of crops (CWR), as important genetic resources for crop Given limited resources, a national conservation strategy for CWR requires the We will utilize a “gap analysis” method aimed at identifying locations of genetic
improvement, represent a dual challenge of requiring conservation as well as access prioritization of species based upon their potential use value, particularly in diversity in the US un- or under- secured in conservation systems12, in order to
for use. In many regions these resources are threatened by habitat modification, contributing to agriculture through crop breeding. This necessarily limits the term inform planning of germplasm collecting for ex situ conservation13, as well as to
land use changes, and other factors, requiring their urgent collection and long-term ‘crop’ to those cultivated species with modern cultivar forms and active breeding identify key areas in order to make recommendations for in situ conservation. We
availability for research and breeding from ex situ genebank collections, as well as programs. are gathering and geo-referencing species occurrence and conservation data from
their adequate protection in situ in order to support an evolving genepool for the We compiled a list of the world’s major crops from FAOSTAT global production online resources, herbarium and genebank databases, and in collaboration with
uses of the future. It is becoming increasingly feasible to formulate a large-scale and consumption data7; crops listed in Annex 1 of the International Treaty on Plant researchers. The results of the gap analyses will form the basis for a prioritization
plan for the efficient and effective conservation of CWR diversity due to Genetic Resources for Food and Agriculture8; and the major and minor crops listed of taxa across genepools for collecting, and the identification of the highest priority
advancements in understanding the taxonomic relationships of CWR, in in Appendix 2 of the World Atlas of Biodiversity9 and in Prescott-Allen and Prescott- locations for the most efficient and effective collecting as well as for the
distribution modelling through Geographic Information Systems tools, and in Allen (1990)10. Crops on the collated list were then categorized by importance, establishment of protected areas for CWR (Figure 1).
conservation science and technologies. CWR resources are often globally with the major crops given highest priority. The national inventory was then
important, yet their management is dependent upon national policy and interests. Figure 1: wild Phaseolus and protected areas in the SW US
reviewed in order to identify CWR taxa of high potential use value that were not
We suggest that an effective national approach toward the conservation of CWR already included within the priority crop list, as well as for identification of taxa of
entails the systematic coverage of this diversity in a network of genetic reserves, significant direct use value to food production or to the economy in the U.S. (e.g.
with the range of genetic diversity found within these taxa safeguarded in sugar maple (Acer saccharum), wild rice (Zizania spp.), and pecan (Carya illinoinensis).
genebanks. We present the work to date on planning for a national effort to These taxa were included in the prioritization as iconic valuable wild species
conserve CWR and economically important wild taxa occurring in the United occurring in the US. Finally, any additional genera known to be included within the
States. genepools of the crops on the priority lists were added (e.g. Aegilops for wheat,
Tripsacum for maize).
The resulting list of the world’s major crop genepools includes 255 crops/281
genera (108 crops/126 genera in Priority 1; 147 crops/155 genera in Priority 2).
This list includes all the most important agricultural crops around the world by a
number of measures, and covers all major crops listed in FAOSTAT for US
production and food supply7.
Priority taxa for a national CWR conservation strategy
2,012 taxa of 159 priority genera occur in the US- 904 taxa of 74 Priority 1 genera
(Table 1), and 1,108 taxa of 85 Priority 2 genera. Important crops with rich native
genepools include Allium (onion), Cucurbita (squash), Fragaria (strawberry),
Cucurbita foetidissima Juglans hindsii Vitis rotundifolia
Helianthus (sunflower), Ipomoea (sweet potato), Lactuca (lettuce), Phaseolus (bean),
Prunus (cherry, almond, peach), Ribes (currant), Rubus (raspberry), Saccharum (sugar
cane), Vaccinium (blueberry, cranberry), and Vitis (grape).
Development of a national inventory of CWR and useful species
To target conservation efforts for a national conservation strategy, we focused on
We are compiling a national inventory of taxa representing CWR of the world’s
Priority 1 genepools. This focus includes the richest genepools of native diversity
crops, and wild species directly used for food, fiber, forage, medicinal, and other occurring in the US that have the potential to contribute to crop improvement, and
purposes. With the aim of including as many species as possible with the potential also attempts to cover the major wild species directly utilized for food or
to contribute to crop improvement, we defined CWR following Maxted (2006)1, medicine. The Priority 1 list is currently under review by crop breeders and Collaborate with us!
genetic resources experts. Table 1: Priority 1 Genera The gap analysis method is dependent upon the quality of data utilized. Important
broadened to include species within the tertiary genepool. The national inventory
species occurrence data are not easily available online, and ecogeographic datasets
was compiled from data sources including the Germplasm Resources Information Acer Carya Elymus Leymus Prunus Trifolium
benefit significantly from expert review. We would therefore like to ask for your
Network (GRIN) World Economic Plants Database2, based on Wiersema and Leon Aegilops
Agave
Cinnamomum
Cocos
Ficus
Foeniculum
Linum
Malus
Psathyrostachys
Pseudoroegneria
Tripsacum
Vaccinium collaboration in sharing with the project occurrence and conservation data on the
(1999)3; completed volumes of the Flora of North America4; McGuffin (2000)5 (for Agropyron Colocasia Fragaria Manihot Psidium Vanilla priority genera. If you have expertise in the taxonomic and genetic relationships
Allium Corylus Gossypium Medicago Pyrus Vernicia
herbs and medicinal species); and the Native Seed Network Database6 (for Artocarpus Cucumis Helianthus Olea Ribes Vicia
within the genepools, or in the distribution and/or conservation status of taxa, we
restoration species). Both native and non-native taxa were included. USDA Asparagus Cucurbita Hordeum Papaver Rubus Vigna would appreciate your inputs for validating the results of the taxonomic work and
National Plant Germplasm System (NPGS) curators and crop experts then
Avena Cynara Ilex Pennisetum Saccharum Vitis
the gap analyses. Please contact us at c.khoury@cgiar.org.
Beta Daucus Illicium Persea Simmondsia Zizania
contributed revisions. The national inventory currently contains over 3,000 taxa. Brassica
Capsicum
Dioscorea
Diospyros
Ipomoea
Juglans
Phaseolus
Pinus
Solanum
Sorghum
References
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Gap Analysis Methodology for Collecting Crop Genepools: A Case Study with
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Available online at: http://faostat.fao.org/. CWR photos from www.plantsystematics.org
Vaccinium oxycoccos Rubus hawaiensis particular attention in conservation recommendations.