A new gene to stop barley leaf rust

The University of Queensland's Dr Lee Hickey led a team that discovered that the gene Rph20 provides resistance to leaf rust in some barley variety adult plants.

“Leaf rust is a fungal disease that could destroy almost a third of the nation's barley crop,” said Dr Hickey, a research fellow at UQ's Queensland Alliance for Agriculture and Food Innovation.

“The discovery will enable selective breeding of barley that will provide genetic protection to the disease.

“This will result in much lower chemical use, reduced crop losses, and a more reliable grain supply.”

Dr Hickey said the crop disease could also leave Aussie beer drinkers thirsty as the country's primary use of barley was to make beer, as well as stock feed.

“But for areas like North Africa and Southwest Asia it is a food staple,” he said.

Dr Hickey teamed up with scientists from the Queensland Department of Agriculture, Fisheries and Forestry, the University of Sydney and Uruguay's Instituto de Investigacion Agropecaria.

Using field trials in Australia and Uruguay, the team was able to identify the specific gene.

They then developed a diagnostic DNA marker to determine the presence of the gene.

Using the marker, they traced the gene's origins to a type of barley first cross-bred in the Netherlands in 1928.

“It was a surprise that we could trace the gene back so far,” Dr Hickey said.

“There have been no reports of a strain of leaf rust that has overcome the Rph20 resistance.”

He said his research also showed that the Rph20 gene had resistance to powdery mildew, another devastating barley disease.

“It seems to be a key gene in the barley genome,” he said.

Dr Hickey has declined to patent the DNA marker, preferring the information to be freely available to other researchers.

The research was partially funded by a grant from the Grains Research and Development Corporation.

Dr Hickey was one of 12 early-career scientists who unveiled their research to the public for the first time thanks to Fresh Science, a national program sponsored by the Australian Government through the Inspiring Australia initiative.