The breakthrough is buoying hopes that farmers can harness technology to keep up with the rapidly rising global demand for food.

More than a decade ago researchers at the University of Adelaide began cross-breeding varieties of durum wheat — the grain used to make noodles and pasta — to come up with a strain that would thrive in the 30 per cent or so of soils worldwide that have a high sodium content.

By mixing ancestors of 10000-year-old durum with modern variants the team, led by Matthew Gilliham, isolated the gene that in the past had given durum wheat its tolerance to salt but which by genetic diversity had been lost.

“Now we’ve discovered the gene it’s possible to find similar genes in other crop species or transfer this gene to other crops species by using modern genetic modification techniques,” Gilliham said.

Work has already started on breeding up a salt-tolerant strain of the wheat used to make bread.

The work to produce the world’s first salt-tolerant wheat strain is detailed in a paper published in the journal Nature Biotechnology.

“The salt-tolerant gene prevented salt build-up in leaves,” Gilliham said. “Basically it prevents salt being stored in the shoots. It stores them lower down where it is less toxic.”  Australia is the world’s second-largest wheat exporter after the United States and is billing itself as one of Asia’s major food producers.

“The gene works by producing a protein that removes the sodium from the xylem, which are the ’pipes’ plants use to move nutrients and water from their roots to their leaves,” Gilliham said. “This is not genetic engineering in the modern sense of the word. This was done using the same techniques that have been used for 10000 years.”