Crop wild relatives of the United States require urgent conservation action

National inventory of US crop wild relatives find most taxa to be vulnerable or threatened and nearly all urgent or high priorities for ex situ conservation

GBIF-mediated data resources used : 396,355 species occurrences
Solanum elaeagnifolium
Solanum elaeagnifolium Cav. observed in Texas, USA by moonmist (CC BY-NC 4.0)

With important crops being threatened by global change in their current areas of cultivation, food security may depend on the conservation and accessibility of crop wild relatives (CWR) to contribute genetic traits for plant breeding.

In this paper, US researchers present a national inventory of CWR, classifying taxa by relation to agricultural crops and significance as a wild food source.

Using GBIF-mediated occurrences, the authors modeled the potential distributions of more than 500 prioritized CWR taxa—including wild relatives of apples, barley, grapes, onions, potatoes and zucchini—according to bioclimatic and topographic predictors, showing the highest CWR richness in the Northeast, Midwest and Pacific Northwest.

Preliminary threat assessments identified only 23 taxa as of least concern (LC), while more than 500 taxa were near threatened (NT) or worse, including 42 taxa potentially critically endangered (CR).

While 400 institutions hold accessions of at least one US native CWR, 14 per cent of the assessed taxa are completely absent from seed banks and botanic gardens. The study further assessed more than 75 per cent of taxa as urgent collection priorities to address gaps in ex-situ conservation.

Khoury CK, Carver D, Greene SL, Williams KA, Achicanoy HA, Schori M, León B, Wiersema JH and Frances A (2020) Crop wild relatives of the United States require urgent conservation action. Proceedings of the National Academy of Sciences. Proceedings of the National Academy of Sciences 117(52): 33351–33357. Available at: