Scientists develop blight resistant GM potato

UK scientists have developed a genetically modified (GM) potato which is resistant to late blight. The three-year study on Desiree potatoes was funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and The Gatsby Foundation.

In northern Europe, farmers typically spray a potato crop 10-15 times, or up to 25 times in a bad year.

In the third year of the trial (2012) the potatoes experienced ideal conditions for late blight. The scientists did not inoculate any plants but waited for races circulating in the UK to blow in.
Non-transgenic Desiree plants were 100 per cent infected by early August while all GM plants remained fully resistant to the end of the experiment.

There was also a difference in yield, with tubers from each block of 16 plants weighing 6-13 kg while the non-GM tubers weighed 1.6-5 kg per block.

Scientists introduced a gene from a South American wild relative of potato which triggered the plant’s natural defence mechanisms by enabling it to recognise the pathogen.

Cultivated potatoes possess around 750 resistance genes but in most varieties, late blight is able to elude them.

Professor Jonathan Jones from The Sainsbury Laboratory (TSL) said: “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.

“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.”

Scientists hope to replace chemical control with genetic control, though farmers might be advised to spray even resistant varieties at the end of a season, depending on conditions.