Crop Wild Relatives and Climate Change Adaptation

Crop wild relatives contain a multitude of genes of potential value for plant breeding. Among these are many traits that are relevant for climate change adaptation.

Crop wild relative species are distributed across a wide range of habitats, including mountains, deserts, grasslands, salt marshes, and rainforests. They have evolved many different strategies for surviving in these diverse climatic conditions. The genetic traits that allow CWR species to thrive in different, sometimes, extreme habitats, represent a valuable resource for plant breeding in the context of climate change.

Climate change is projected to increase the frequency and severity of droughts, increase growing season temperatures, increase soil salinity in coastal areas, and contribute to the spread of pests and diseases. [i] Crop wild relatives can contribute to climate change adaptation when they possess a trait that has the potential to help crops become more resilient and adaptive under the changing environmental conditions projected under climate change. For example:

• Genes for drought-tolerance have been identified in the wild relatives of the tomato, chickpea, barley, rice, and wheat.[ii],[iii]

• Genes for salt tolerance have been found in a number of crop wild relatives, including wild rice species Oryza coarctata [iv] and wild sunflower species Helianthus paradoxus. [v]

• Many crop wild relatives possess valuable genes for resistance to pests and diseases. [vi]

CWR species also have the potential to contribute to climate change mitigation through the provision of traits that allow crops to be grown less carbon-intensively (mainly through increased efficiency of input use). For example, using crop wild relatives to introgress a trait for nitrogen use efficiency into a given crop could allow the reduction of fertilizer use, thus lowering the overall carbon-intensity of growing that crop. Traits useful for climate change adaptation are often also useful for climate change mitigation, since they tend to allow crops to produce more with less.

Overall, with enough investment, crop wild relatives have the potential to significantly contribute to climate change adaptation, while providing mitigation co-benefits, and to help facilitate the transition towards more resilient, low-carbon economies and societies. The diagram below illustrates how different CWR traits and genes can help agriculture respond to some of the threats posed by climate change.