Unlike bread wheat, durum wheat is generally intolerant to salinity

Flickr/ Aske Holst

A variety of wheat that thrives on salty soils has been bred by scientists who say they will make it freely available to the developing world.

The enhanced durum wheat is 25 per cent more productive in saline soils than its normal counterpart, according to Rana Munns, chief research scientist at the Australia-based CSIRO Plant Industry.

Munns and her team isolated two salt tolerance genes from an old species of wheat (Triticum monococcum) and, using non-GM methods, introduced them into commercially important Australian durum wheat (Triticum durum)lines.

The genes limit the passage of sodium from the roots to leaves, where it can be toxic to the plant.

Some 17 million hectares of durum wheat are cultivated worldwide, with 60 per cent of cultivation taking place in developing countries in regions including the Middle East, North Africa, Latin America and central India, according to the Food and Agriculture Organization.

Some soils are naturally salty, for example in India and in semi-arid regions such as the Middle East, but salinity can also be caused by irrigation. Around one third of the world's food is produced on irrigated land, and is thus susceptible to salinity problems. Introducing salt-tolerance genes to crops is one way of dealing with this issue (see Genetic change could make crops thrive on salty soils).

"The [salt tolerance] gene is now present in an Australian durum wheat line," Munns told SciDev.Net. "This line is available to breeders in developing countries for backcrossing into local durum wheat cultivars."

Unlike bread wheat, durum is generally intolerant to salinity so the first salt-tolerant durum line is a great achievement, said Francis Obgbonnaya, researcher at the International Center for Agricultural Research in the Dry Areas, Syria.

"The additional significance is that it is non-GM and CSIRO Plant Industry is willing to share it with developing countries," he said. 

Rodomiro Ortiz, a consultant for Mexico-based International Maize and Wheat Improvement Center (CIMMYT), said that the work illustrates the power of using non-GM approaches to make use of natural genetic variety to improve crops.

But Hans-Joachim Braun, global wheat director at CIMMYT, said: "Breeding salt tolerant plants for such systems will provide a short term solution but in the long term this will only make the situation worse as it allows farmers to continue with sub-optimal practices that increase salt concentration. Such salt problems must be addressed through engineering and agronomy practices".