Image caption The humble spud provides the world's fourth-largest crop

An international team has uncovered the full DNA sequence of the potato for the first time, the journal Nature reports.

The breakthrough holds out the promise of boosting harvests of one of the world's most important staple crops.

Researchers at the James Hutton Institute in Dundee, which contributed to the work, say it should soon be possible to develop improved varieties of potato much more quickly.

The genome of an organism is a map of how all of its genes are put together.

Each gene controls different aspects of how the organism grows and develops.

Slight changes in these instructions give rise to different varieties.

Each individual has a slightly different version of the DNA sequence for the species.

Professor Iain Gordon, chief executive of the James Hutton Institute, said decoding the potato genome should enable breeders to create varieties which are more nutritious, as well as resistant to pests and diseases.

Colour and flavour

He hopes it will help meet the challenge of feeding the world's soaring population.

The research is far from complete. Analysing the genetic sequence of the plant will take several more years.

At the moment it can take more than 10 years to breed an improved variety.

By locating the genes that control traits like yield, colour, starchiness and flavour, the research should make it possible to develop better spuds much more quickly.

Potatoes provide the world's fourth-largest crop, with an annual, global yield of 330m tonnes.