How wild potatoes could help spuds resist the deadly blight that caused the Irish Potato Famine

Scientists believe that genes from wild potatoes could help protect regular crops from the disease that caused the Irish potato famine.

Wild potatoes could save our beloved spuds from their biggest threat: late blight.

Commercially grown cultivars are extremely vulnerable to this aggressive disease, which was behind the potato famines that devastated Ireland, the Highlands and large swathes of Northern Europe in the mid 19th-century, leading to the death of more than one million people.

Caused by a fungus-like mould that thrives in warm, wet weather, late blight destroys leaves and stems, killing a plant in days and often making the tubers rot. According to research by plant scientists at the University of Dundee and the James Hutton Institute, the disease spreads easily among British and American potato crops because the genetic differences in their lineage are very limited.

‘Our preliminary data suggests that the most commercially valuable potato varieties grown in the UK and the US contain a maximum of four genes already defeated by the late blight pathogen, P. infestans,’ explains Dr Ingo Hein, principal investigator in plant pathogen co-evolution at the University of Dundee.

However, scientists believe that genes from wild potatoes can be used to help regular spuds become more resistant to late blight.

‘Crucially, we have been able to identify new genes that remain effective against this disease, which are not current used in commercial potato production, and so, by combining these effective genes, we can prolong the longevity of individual resistances to the disease,’ continues Dr Hein.

This would not only help keep chips on British plates but also reduce the amount of chemicals used in potato-growing.

‘Currently, the control methods for late blight in most parts of the world are based mainly on the use of chemical sprays which can be environmentally hazardous and expensive,’ notes Dr Hein.

He and his team have now secured £625,000 in funding from the Biotechnology and Biological Sciences Research Council to identify the most blight-resilient potatoes.