Image caption Wheat provides one fifth of the global population's intake of calories

Scientists have unlocked key parts of the complex genetic code of wheat, one of the world's most important crops, which could help improve food security.

The team hopes the data will accelerate the development of varieties more resilient to stresses, such as disease and drought, that cause crops to fail.

The 2012 wheat harvest was hit by extreme weather events around the globe, causing a sharp rise in prices.

Details of the findings have been published in the journal Nature.

In 2011, the global output of 681 million tonnes made bread wheat the third most-produced food crop (behind maize and rice) and accounted for about 20% of the calories consumed by the world's population.

The study - involving UK, US and German scientists - has built on the 2010 publication of the draft genome, resulting in the development of tools that can decipher the genetic code of segments of the genome.

The researchers hope the information could help breeders produce varieties that are better suited to cope with future threats to production yields.

Key traits

"One of the things about why bread wheat is grown all over the world is that you are able to adapt it to local environments," explained co-author Neil Hall from the University of Liverpool's Institute of Integrative Biology.

"The tools we have generated will allow people to more rapidly identify where in the genome these traits are located and breed them into new lines."

Facts about the 'staff of life' Wheat ( Triticum spp ) was one of the first domesticated food crops

) was one of the first domesticated food crops For about 8,000 years, it has been the basic staple food of many major civilisations

The crop can be grown from equatorial regions to within the Arctic Circle

Wheat has been recorded growing as high as 4.5km above sea level

Raised bread loaves are possible because the wheat kernel contains gluten, which traps minute CO2 bubbles when fermentation occurs

It is grown on more than 240m hectares, more than any other food crop (Source: UN FAO)

Prof Hall told BBC News that the tool would also "help identify disease resistance and better grain quality".

"We know that there are wild varieties that are particularly good when it comes to drought resistance or flood resistance, but they have very low productivity," he added.

"You have got to get those high-productivity traits into backgrounds that are more resistant to things like drought or disease."

The researchers say that breeders and researchers will now be able to select plants with desirable combinations of genes using the genetic landmarks (known as markers) identified in the study.

"With markers, breeders can track the genetic make-up of plants when new varieties are being bred," explained co-author Prof Mike Bevan from the John Innes Centre, Norfolk.

"Plants lacking the desired traits can be eliminated more efficiently, and those with the desired characteristics identified more quickly, speeding up the production of new varieties."

Prof Hall said that while it was difficult to forecast when the first varieties of wheat using the new technique would be grown, he said that it was possible that it could be as little as five years.

Prof Douglas Kell, chief executive of the UK's Biotechnology and Biological Sciences Research Council, which funded the research, commented: "In the face of this year's wheat crop losses, and worries over the impact on prices for consumers, this breakthrough in our understanding of the bread wheat genome could not have come at a better time.

"This modern strategy is a key component to supporting food security and gives breeders the tools to produce more robust varieties with higher yields."