A team of Australian scientists involving the University of Adelaide have bred salt tolerance into a variety of durum wheat that shows improved grain yield by 25 per cent on salty soils.

As the problem of rising soil salinity, caused by overdrawn water tables and excessive development of fresh water resources increases around the world, this Australian breakthrough could prove a life-saver for many people.

Using “non-GM” crop breeding techniques, scientists from CSIRO Plant Industry have introduced a salt-tolerant gene into a commercial durum wheat. Researchers at the University of Adelaide’s Waite Research Institute led the research into how the gene delivers salinity tolerance to the plants. The results were published in the journal Nature Biotechnology.

CSIRO Plant Industry scientist Dr Rana Munns said the research is the first of its kind in the world to fully describe the improvement in salt tolerance of an agricultural crop – from understanding the function of the salt-tolerant genes in the lab, to demonstrating increased grain yields in the field.

Dr Munns said, “The work is significant as salinity already affects over 20 per cent of the world’s agricultural soils, and salinity poses an increasing threat to food production due to climate change.”

Domestication and breeding has narrowed the gene pool of modern wheat, leaving it susceptible to environmental stress. Durum wheat, used for making such food products as pasta and couscous, is particularly susceptible to soil salinity.

Salty soils are a major problem because if sodium starts to build up in the leaves it will affect important processes such as photosynthesis, which is critical to a plant’s success. The salt-tolerant gene, known as TmHKT1;5-A, works by producing a protein that removes the sodium from the cells lining the xylem, which are the ‘pipes’ plants use to move water from their roots to their leaves.

Dr Munns said new varieties of salt-tolerant durum wheat could be a commercial reality in the near future.

“This means we have produced a novel durum wheat that is not classified as transgenic, or ‘GM’, and can therefore be planted without restriction,” she said.

The researchers are taking their work a step further and have now crossed the salt-tolerance gene into bread wheat. This is currently being assessed under field conditions. The salt-tolerant wheat will be used by the Australian Durum Wheat Improvement Program (ADWIP) to assess its impact by incorporating it into recently developed varieties as a breeding line.

The paper’s senior author, Dr Matthew Gilliham from the University of Adelaide said, “With global population estimated to reach nine billion by 2050, and the demand for food expected to rise by 100 per cent in this time, salt-tolerant crops will be an important tool to ensure future food security.”

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