A University of Copenhagen professor has said food crops should be 'rewilded' to imbue them with lost traits that have been bred out of them over hundreds or thousands of years.

Calls to protect crops' wild relatives have grown in volume in recent years, in order to preserve the biological diversity that has been bred out of food crops over many centuries (but especially so over the course of the last century), and with it potential resistance to certain climatic conditions and diseases.

Elaborating on these calls, and using an idiosyncratic definition of the term 'rewilding', a plant scientist at the University of Copenhagen has called for beneficial traits to be returned to crops. On Tuesday (16th December), Copenhagen's Michael G. Palmgren said that genes with beneficial traits that have accidentally been bred out of food crops over the last millennia should be reinserted.  

Palmgren believes that, "Once the genes that have been mutated unintentionally have been identified, the next step would be to re-establish wild-type properties. Rewilding would allow crop plants not only to better utilise available resources in the environment and have higher nutritional value, but also to better resist diseases, pests, and weeds."

Prof Palmgren is advocating the genetic modification of plants, but claims his recommended 'rewilding' would be less controversial than current GM techniques, as the process would involve the transfer of genes from closely related species, not from unrelated organisms.

Palmgren, who did not quantify the potential increases in yield or resilience his proposal could produce, did acknowledge that "Studies tell us that many consumers look with some reservation upon GMO-based products, in part because they are considered alien. Rewilded crops represent a different path, yet if branded as GM products may likely face considerable challenges for market penetration."

Rewilding is typically viewed as the restoration of degraded habitats, by connecting different areas of more natural ecosystems (based on the idea that smaller, fragmented areas are more vulnerable) and reintroducing threatened species, including apex predators, to ensure more functioning biodiversity and attempt to recreate or mimic the environment's more natural state.

Though Prof Palmgren believes his proposals could drive up food production – and 'feed the world's growing population' – as well as making crops more resilient, sustainable farm groups have suggested his controversial strategy risks continuing down the same narrow path that has led to the homogenisation of crops and the multitude of problems agriculture now faces.

Soil Association policy director, Peter Melchett said that, whilst Palmgren's recommendations reflect the growing interest in the useful traits in older versions of modern crops, the recommendations appear to ignore key systemic issues under debate in world agriculture.

Melchett said, "Many scientists are now recognising that ancient relatives of modern crops like wheat, barley, oats and a range of fruits and vegetables, contain vitally important characteristics which have been lost in recent decades, as plant breeding focused solely on increasing yields in response to manufactured Nitrogen fertiliser, with crops reliant on high doses of pesticides."

"It is widely accepted that modern crop plants have lost significant levels of beneficial nutrients compared to varieties grown half a century or more ago."

He added that a recent meta-analysis showed that crop varieties used in organic and lower-impact agriculture are more resilient, more resistant to disease and insect attack, and less depends on high levels of Nitrogen fertiliser than ones relying on conventional, high-input packages.

The Soil Association policy advisor also claimed Palmgren's calls for 're-wilding' crops "Ignores the fact that a great deal of scientific work is already underway to investigate desirable traits in older versions and wild relatives of our major crop plants," pointing out that the European Union has funded a major research project looking at crop varieties suitable for low-input systems.

He concluded that "None of this… research requires the use of GM technology, and that outdated technology is unlikely to be helpful in acquiring complex, multi-gene traits from wild plants or older crop varieties."