East Anglian scientists prove GM potatoes can withstand potato blight

GM potato trial at the John Innes Centre in Norwich.
Prof Jonathan Jones with a GM potato plant

GM potato trial at the John Innes Centre in Norwich. Prof Jonathan Jones with a GM potato plant picture by Adrian Judd for EDP Mike Pollitt

Scientists at East Anglia’s world-class plant research centre have successfully proved that GM potatoes can withstand attacks by a devastating disease.

Results of the three-year trials could help to reduce the £3.5bn global losses caused by late potato blight.

These trials of two varieties of potatoes, containing genes from a wild relative, survived one of the worst seasons for late blight for more than a quarter of a century.

Already this technology, developed by a team at the Sainsbury Laboratory, is now helping scientists in the United States to produce new potential varieties of potatoes with late blight resistance.

The project, which was led by Prof Jonathan Jones, and partly funded by research charities and also the taxpayer, involved planting about 192 potato plants inside a three-metre high steel security fence at Colney on the Norwich Research Park.

In the third and final season, the GM potatoes survived while the ordinary commercial variety, Desiree, was 100pc infected by early August. And also the blocks of 16 GM tubers each weighed between 6kg and 13kg while the untreated blocks weighed between 1.6kg and 5kg.

A paper, which is published today and has been peer-reviewed for the Royal Society’s scientific journal, reports that the team led by Prof Jones has made further progress in developing resistance to late blight.

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“With new insights into both the pathogen and its potato host, we can use GM technology to tip the evolutionary balance in favour of potatoes and against late blight,” said Prof Jones.

The introduced gene, from a South American wild relative of potato, triggers the plant’s natural defence mechanisms by enabling it to recognise the pathogen. While cultivated potatoes have a total of around 750 resistance genes, late blight is usually able to infect plants.

“Breeding from wild relatives is laborious and slow and by the time a gene is successfully introduced into a cultivated variety, the late blight pathogen may already have evolved the ability to overcome it,” said Prof Jones.

The trials were carried out with Desiree and also Maris Piper potatoes, which were among key varieties grown commercially. They were grown in pots in a greenhouse and were then transplanted after any risk of frost to test the response in a field situation. All the potatoes, which were grown inside the £20,000 green cage, were later destroyed and were not allowed to enter the food chain.

Late blight has been one of the biggest challenges to the production of potatoes around the world. In the middle years of the 19th century, strains were responsible for the Irish Potato Famine, which resulted in the loss of an estimated one million lives to starvation between 1845 and 1847.

To grow high-quality crops for the table, for processing into chips and crisps and a range of other products, growers have to rely on the only weapon in the plant protection armoury, spraying a fungicide to check spread of the infection.

Typically, a main crop potato field might be sprayed between 10 and 15 times before harvest and even up to 25 times in a bad blight year across most of Europe.

It was also costly, with each application costing about £20 an acre, and in moist and humid conditions, might have to be repeated every five to seven days.

The research, which was part-funded by the Biotechnology and Biological Sciences Research Council, cost more than £750,000, plus a further £46,039 for security to safeguard the field trials.

The trials have been criticised by anti-GM group, GeneWatch, which claims they have cost £3.2m. “Taxpayers’ money is being wasted on yet more GM research that is a very long way from delivering what farmers really need” said Dr Helen Wallace, director.

“There are blight-resistant non-GM potatoes already on the market. Why waste money, take unnecessary risks, and end up with a product that no one wants to eat?”