GM potato ‘completely resistant’ to late blight

A genetically-modified potato, altered by a gene taken from a variety of potato that grows wild, is completely resistant to late blight, which costs farmers globally nearly €5 billion a year.

The research, published today, has provoked excitement amongst scientists, with one arguing that it offers farmers a tool in a 170-year-old battle “that stacks the odds in our favour”.

In the trials carried out outside Norwich, the Desiree potato -a strain developed in the Netherlands in the 1960s - was altered by a gene taken from a wild variety of potato, Solanum venturii.

The Desiree, a waxy variety of potato used in all types of cooking from roasting to mashing and salads, has been favoured by growers because it is fairly resistant to disease.

Over three years, between 2010 and 2012, a GM-modified version of Desiree was grown alongside non-GM varieties to test its ability to withstand potato blight, Phytophthora infestans.

In 2010, blight arrived when plants were already fully-grown and the tubers mostly developed; while in 2011 East Anglia was exceptionally cool and dry.

However, the last year of the trial in 2012 had the most dangerous conditions for blight: repeated periods in July and August where temperatures were above 10 per cent for two days at a time, along with high humidity.