Distributions and Conservation Concerns for Crop Wild Relatives in the United States.

The use of crop wild relatives (CWR) in breeding is likely only to increase as utilization techniques improve and crop improvement under global change becomes more urgent. Significant gaps remain in the conservation of these genetic resources. Initial steps have been completed resulting in a CWR inventory of taxa occurring in the United States, with suggested prioritization of species based upon potential value in crop improvement. U.S. CWR are related to a broad range of important food, forage and feed, medicinal, ornamental, and industrial crops. Some potentially valuable CWR are threatened in the wild, including relatives of sunflower, walnut, squash, wild rice, raspberry, and plum.  Few accessions of such taxa are currently conserved ex situ. Potential distribution models and richness maps for these taxa enabled the identification of hotspots of taxonomic diversity of CWR in the U.S. Our ‘gap analysis’ compared these models to the extent of germplasm conserved ex situ, enabling the identification of those taxa and geographic areas of particular conservation concern. Both the urgent collection for ex situ conservation and the in situ management of such taxa in protected areas are warranted. How do we move forward to accomplish this? Initial efforts are underway to develop a strategic framework between the USDA National Plant Germplasm System and U.S. Forest Service. We discuss how efforts can be broadened to encompass other national and state natural resource management agencies, to develop an inter-agency, U.S. CWR strategy aligned with regional and global initiatives to conserve and provide access to CWR diversity.