Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 20, 2013
Publication Date: April 29, 2013
Citation: Khoury, C., Greene, S.L., Wiersema, J.H., Maxted, N., Jarvis, A., Struik, P.C. 2013. An inventory of crop wild relatives of the United States. Crop Science. 53:1496-1508. Interpretive Summary: Wild relatives are a critical source of genes that have been used to breed improvements, such as disease, insect, and drought tolerance, into crops. Without the adaptive genes that these wild relatives have provided, most of our most valuable food crops would not have survived past disease or pest epidemics. Similar challenges, especially those related to climate change, face current and future crop breeders. Many locations where crop wild relatives grow are gradually being degraded or destroyed, so the need to conserve these plants and their habitats for future use is becoming increasingly urgent. In order to help save these wild relatives we must first determine what they are, where they are, and which ones are the most important to conserve. This paper provides an inventory of wild relatives of the world’s most important crops that occur natively in the United States. This information, to be made available also as an internet database, will be used to assess and prioritize the conservation of crop relatives and their genetic resources for future generations, both in natural habitats and in genebanks.
Technical Abstract: The use of crop wild relatives (CWR) in breeding is likely to continue to intensify as utilization techniques improve and crop adaptation to climate change becomes more pressing. Significant gaps remain in the conservation of these genetic resources, constraining availability for research. As a first step toward a national strategy for the conservation of CWR, we present an inventory of taxa occurring in the United States, with suggested prioritization of species based upon potential use value in agricultural crop improvement. 4,600 taxa from 985 genera and 194 plant families are listed, including CWR of potential value via breeding as well as wild species of direct use for food, forage, medicine or as herbs, ornamentals, and/or for environmental restoration. CWR identified in the US are related to a broad range of important food crops such as sunflower, blueberry, and grape, as well as forage and feed, medicinal, ornamental, and material/industrial crops. Some potentially valuable species are threatened in the wild, including relatives of sunflower, walnut, squash, wild rice, and plum, and few accessions of such taxa are currently conserved ex situ. Suggested prioritization of taxa for conservation focuses upon 821 taxa from 69 genera primarily related to major food crops, particularly the approximately 285 native taxa from 30 genera that are most closely related to such crops. Both the urgent collection for ex situ conservation and the management of such taxa in protected areas are warranted. Broad partnerships between concerned organizations are needed, aligned with regional and global initiatives to conserve and provide access to CWR diversity.