Gene key to defend barley from rust

AN INTERNATIONAL study led by a Queensland scientist has found a way to better safeguard an important food crop and the world’s beer supply.

The study, led by University of Queensland geneticist Dr Lee Hickey, successfully identified a gene that protects barley against leaf rust, a disease that hit Queensland farmers in 2010 and could destroy almost a third of the national crop.

In Australia, barley is used primarily for beer and stockfeed. The situation is much more significant in North Africa and Southwest Asia, where barley is a critical human food, and rust commonly attacks vulnerable plants.

Barley farmers around the world spend large amounts of money on fungicides to combat leaf rust. Dr Hickey’s discovery will enable selective breeding of barley to provide genetic protection to the disease, resulting in much lower chemical use, reduced crop losses, and a more reliable grain supply.

Dr Hickey, a research fellow at the University of Queensland’s Alliance for Agriculture and Food Innovation, conducted his pioneering study with collaborators from the Queensland Department of Agriculture, Fisheries and Forestry, the University of Sydney and Uruguay’s Instituto de Investigacion Agropecaria.

In field trials in Australia and Uruguay, the research team was able to identify a specific gene, Rph20, that provided resistance to the leaf rust pathogen in the adult plants of some barley varieties. The team then successfully developed a diagnostic DNA marker to determine the presence of the gene. The researchers traced its origins back 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,” he said.