RESEARCHERS expect to have genetically modified salt tolerant cereal lines in the paddock for trials next year, in a big boost for the 70pc of Australian farmers affected by salinity.
A project into salt tolerance, conducted jointly by the University of Adelaide and the Australian Centre for Plant Functional Genomics (ACPFG) has had some promising results.
"I'm excited by what is happening – the preliminary results are looking good, we are confident we will be able to reduce the amount of salt that gets into the plant, which then limits the yield," project leader Mark Tester said.
He said there was huge application within the Australian grains industry for salt tolerant lines, with research out of the University of Adelaide showing that 70pc of the nation's grain belt was in some way affected by excess salinity.
"We estimate that salinity could be costing up to $200 million annually, working on yield limitations of 10pc across 70pc of the cropping area," Prof Tester said.
"It is certainly pegging back crop yields across a large part of the wheat belt, and it's not necessarily where salt is visible in the field – the major problem is with salt present in the subsoil."
Work is being done on three cereal varieties – rice, barley and wheat.
Unfortunately, Prof Tester said the wheat, Australia's most important crop, was the hardest species to build, due to its complex genetic make-up.
"We started with work on the trial species, a brassica that acts as the 'lab rat' of plant breeding, and we have then built the salt tolerant rice and barley varieties, with the wheat not far away.
"There have been results that have shown we have got it right in rice, which is a much easier plant to work with, and we're expecting some greenhouse data from the barley and the wheat this year.
"Field trials of some lines are likely to commence next year."
The core of the work involves keeping the salt in parts of the plant where it does less damage.
The genetic modificiation allows the plant to keep salt out of the leaves of a model plant species.
The researchers modified genes specifically around the plant's water conducting pipes so that salt is removed from the transpiration stream before it gets to the shoot.
"What we are doing is simply amplifying a natural process."
Prof Tester warned that the salt tolerant lines would not cure the problem of salinity.
"We are not building mangroves here – we don't yet know how much of that 10pc yield constraint we will be able to recapture – but we're hoping it will be around half, cutting yield constraints to 5pc."
The work has been conducted in the shadow of high profile research into drought tolerance, but Prof Tester believes salt tolerant lines will hit the market first.
"I think drought tolerance is really complex, there is no magic bullet there, but salt tolerance is something more tangible," he said.
However, Prof Tester did think the improvement in a plant's ability to handle salt would allow it access to more water.
"There is chatter between salt and drought tolerance, a spin off benefit of improved salt tolerance will be able to use more water in the soil profile, thus improving plant available water (PAW) levels which will be valuable in dry periods."
The news will be of particular interest to farmers in some of Australia’s worst hit salty patches, such as the eastern wheat belt in WA and parts of the south-eastern Mallee in Victoria.
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