Fruit and Nut Crop Wild Relatives in the United States: a Surprisingly Rich Resource

摘要

When early settlers arrived in the United States they were struck by the many fruits and nuts they recognized, including grapes (Vitis), plums and cherries (Prunus), strawberries (Fragaria), currents (Ribes), blueberries and cranberries (Vaccinium), wild chestnuts (Castanea), filberts (Corylus), and walnuts (Juglans). Native fruit and nut crop wild relatives were an important genetic resource in establishing early commercial production. Today we tend to forget the many native and naturalized plants in the United States that are important crop wild relatives (CWR). Developing a national strategy would be prudent with a national inventory being a logical starting point. We discuss the development of a U.S. CWR inventory that covered crops used for food, fiber, forage, medicine, esthetics, restoration and timber. The preliminary inventory contained over 2600 entries. A total of 364 CWR taxa were useful for breeding 65 different crops. Fifty five percent of these CWR taxa were potential resources for fruit and nut improvement. Many of these fruit and nut CWR have been used extensively by breeders and have contributed important traits such as disease and insect resistance and abiotic stress tolerance. Native species of Vitis, Juglans, and Prunus are important rootstocks. Although germplasm collections exist, we need to revisit our efforts to conserve the native and naturalized germplasm in our own back yard. A comprehensive national CWR inventory will help us focus on setting priorities and developing a national strategy to conserve these important genetic resources to ensure their use in the future.