BOILED, baked, chipped, roast or mashed, a meal is rarely quite complete without a serving of the nation’s favourite starch on the side.

Scots have tucked into potatoes ever since the first spuds arrived from South America in the late 16th century, while Scottish growers today supply about 35 per cent of the UK’s supplies. 

But new research suggests that genetic differences and climate change have left the humble spud vulnerable to the same disease that caused the devastating Irish and Highland potato famines. 

According to plant scientists at Dundee University and the James Hutton Institute, commercial potato crops in Scotland and America are under constant threat of potato blight, the disease that sparked the 1845 Irish famine and also devastated Highland crops. 

Now, in an attempt to make our favourite varieties of potatoes more effective at staving off the disease and any effects of climate change, scientists have turned to unusual varieties of “wild” and often slightly wonky looking potatoes to help battle the blight. 

They have developed tools which have unravelled for the first time the historical and geographical patterns of resilient genes in American and British cultivated potatoes, as well as identified genes in the wild varieties that could help boost commercial crops’ resistance. 

It’s hoped that by combining the genes, potato farmers will be able to grow “super spuds” with extra-resistance and therefore ensure tatties stay on the menu. 

Dr Ingo Hein, Principal Investigator in plant pathogen co-evolution, says tackling the threat of blight using gene technology developed in Scotland in collaboration with the Sainsbury Laboratory in Norwich, would also help farmers avoid the use of pesticides on their crops. 

“Our preliminary data suggests that the most commercially valuable potato varieties grown in the UK and US contain a maximum of four genes already defeated by the late blight pathogen, P. infestans,” he said.

“Crucially, we have also been able to identify new genes that remain effective against this disease that are not currently used in commercial potato production. 

“By combining these effective genes we can prolong the longevity of individual resistances to the disease and reduce the need for chemical sprays on plants.

“This is highly relevant for breeding as 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.”

But while the technology to cultivate our favourite potatoes with extra genes to make them disease-resistant may exist, a bigger challenge may be encouraging supermarkets, consumers and potato processors to embrace the new varieties – particularly if the genetic tweak affects how they look, cook and taste.

Mr Hein added: “Potato growers will be delighted because they will need fewer chemical sprays, but the consumer, processor and supermarket who tend to prefer varieties they know. They have the same varieties for 50 or 100 years, and there seems to be a hesitancy to adapt.”

The 19th-century potato blight devastated crops in Ireland but also brought hardship and starvation as it spread across Europe. In Scotland, potato crops continued to be affected by the disease for around 10 years, leading to the demise of Highland and island communities as families were forced to give up their crofts and farms and face little other option but to emigrate to Australia and Canada. 

Many at the time thought the days of cultivating potatoes were over because of the difficulty in eradicating the disease. 

However, just a few miles from where today’s gene research is being carried out, 19th century Dundee fruit farmer William Paterson also used a form of “selective breeding” to grow improved strains of blight-resistance potatoes. 
He imported potatoes from South Africa, America and Australia, and grew the best tubers along with his own strongest crops. His new disease-resistant variety called Victoria is present in the parentage of many potato varieties still grown today.

However, cultivated crops are not as resistant to blight as wild potatoes, while the pathogen responsible is said to have developed over the years to overwhelm what natural resistance commercially-grown crops might have. 

Crops require to be sprayed regularly with pesticides, while some of the country’s most popular varieties, such as King Edwards, are said to be most at risk to the pathogen. 

According to Dr Glenn Bryan, who is responsible for the Commonwealth Potato Collection, which contains about 1,500 samples of wild potato species, European potato crops have been particularly vulnerable to blight since they first arrived here. 

He said: “The first potatoes that came to Europe lacked important genes for resistance. These pathogens that cause disease are very tricky, they can evolve quickly to overcome any weaknesses. They can spread across vast distances. They might have been blown here on the wind from Mexico, or carried on the boots of someone.” 

Potatoes are the fourth most important global crop after wheat, rice and maize.

Wild potatoes can differ dramatically in colour and shape from potatoes typically found in today’s supermarket aisles. In many cases, the potato is no bigger than a 50p coin, while high levels of glycoalkaloids make them bitter and in some cases toxic. 

However, according to Mr Bryan, there could be a place on the dinner table for certain varieties of wild potato.

“Most aren’t cut out for mass production, you couldn’t make chips from them or they are hard to peel because they’re a bit knobbly. They’re also not so easy to grow,” he said. 

“But if you go to the Andes, Peru, Chile and Bolivia, you will see these primitive potatoes being sold. What we see in the supermarkets is a tiny amount of the varieties of potato that we could generate in Britain.”