Salt-Tolerant Wheat Improves Yield by 25%

Adelaide, AUSTRALIAResearchers at the University of Adelaide used a non-GM" crop breeding technique to introduce a salt-tolerant gene into a commercial durum wheat that shows improved grain yield by 25% on salty soils over its durum wheat parent, according to a new study published in the journal Nature Biotechnology. The findings may lead to new varieties of salt-tolerant durum wheat that could be a commercial reality in the near future.

Salinity poses an increasing threat to food production due to climate change, and salinity is a particular issue in the prime wheat-growing areas of Australia, the world's second-largest wheat exporter after the United States. With global population estimated to reach 9 billion by 2050, and the demand for food expected to rise by 100% in this time, salt-tolerant crops will be an important tool to ensure future food security."

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. This is the first study to confirm that the salt-tolerant gene increases yields on a farm with saline soils.  The researchers found that wild relatives of modern-day wheat remain a significant source of genes for a range of traits, including salinity tolerance. They discovered the new salt-tolerant gene in an ancestral cousin of modern-day wheat, Triticum monococcum.

Although the researchers used molecular techniques to characterize and understand the salt-tolerant gene, the gene was introduced into the durum wheat through non-GM" breeding processes, which means they produced a novel durum wheat that is not classified as transgenic, or GM," and can therefore be planted without restriction.

"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 the plant's success," they said. The salt-tolerant gene (known as TmHKT1;5-A) works by excluding sodium from the leaves. It produces 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."

They found under standard conditions, the wheat containing the salt-tolerance gene performed the same in the field as durum that did not have the gene. But under salty conditions, it outperformed its durum wheat parent, with increased yields of up to 25%.