Aberdeen: New way to breed potatoes with resistance to potato blight

Paul Birch of Dundee University, with his team at the Scottish Crop Research Institute and researchers at Aberdeen University have developed a new approach to breeding resistance to the mould-like organism Phytophthora infestans, the cause of late blight in potatoes and tomatoes. This disease is estimated to cost £5-6 billion a year worldwide.

The findings of the research were discussed with industry at a meeting in London last week, and now the approach is to be taken forward in a new project working with colleagues at the Sainsbury Laboratory in Norwich to identify resistance in potato plants that could then be used for breeding new resistant varieties. It is also hoped that it will be possible to combine resistance to late blight with resistance to nematodes, another serious problem for potato farmers, in a single genetically modified variety.

Birch said, “In the past we have tried to breed resistance to late blight by identifying plants that survive a period infection and could, in future generations, potentially give rise to resistant varieties.” This approach is slow and resource-intensive with no guarantee of how long the resistance will last for. To date, all such resistances have been defeated because of the broad extent of variation in the population of P.infestans in the environment.

“With our discovery, we can use genetic analysis to identify plants for breeding that are inherently resistant to infection. When introduced into cultivated varieties, such disease resistance should be far more durable,” Birch said.