Scientists may have advanced in the battle against a threat that could reduce Australia’s valuable wheat crop.
Researchers are developing wheat that is able to withstand a new strain of rust that is in danger of causing major losses to Australia’s $ 6 billion annual grain crop.
Wheat gas rust can invade all parts of the plant, including gas, leaves and inflorescence.
Infectious wheat plants can shorten grain, and untreated disease can reduce grain yields by up to 90 percent.
The new Ug99 snort (discovered in Uganda in 1999) is a true stream of wheat gas rust first discovered in Africa and the Middle East that has acquired over 17 out of 34 genes against gas rust found in wheat.
About 30 percent of conventional wheat varieties are susceptible to the Ug99 strain, and scientists are working to ensure Australian crops are protected from the disease.
Ug99 was not found in Australia, but a revolution could cost the industry up to $ 1.4 billion over a decade, according to the CSIRO.
A major gas rust revolution in Australia in 1973 affected crops across four states and cost the wheat industry between $ 1.8 billion and $ 2.7 billion (in 2014/15 dollars).
In a crisis to avert the Ug99 revolution, scientists are working to develop wheat with a stronger and potentially more stable level of protection by “stacking” five protective genes together.
Researchers combined and applied five different genes against wheat to make it more difficult for rust pathogens to successfully attack wheat.
“Our approach is like putting five locks on a door – you make it very difficult to get in,” said Dr Mick Ayliffe, CSIRO’s lead researcher.
“Robust field tests showed that our approach to gene stacks provided complete protection against the rust pathogens we were targeting.”
Dr Ayliffe said the approach could be used worldwide to protect crops.
“This promising gene stacking technology is a way we could protect not only Australian but international crop rust as well,” said Dr Ayliffe.
“It is a valuable insurance policy in the event that we do not address mutations in wheat rust by a catastrophic disaster, with the potential to bring long-term solutions into the field much faster than we used to. “
Wheat provides about 20 percent of the world’s calorie intake, making crop protection extremely important for world food security, with corn rust also affecting barley, oats , rye and triticale crops.
Dr Ayliffe said the international study had focused on stem rust. However, the same technology can breed against stripe and leaf rust diseases as well, and in existing wheat varieties to combat.
Wheat rust can move quickly, making it difficult for wheat breeders to respond quickly using conventional breeding.
The disease spreads from plant to plant with spores, which are small, light, and last for several days.
In addition to being spread by wind, spores can easily attach to clothing, machinery and equipment allowing movement and dispersal between farms and regions.
Adoption of this new inbreeding technology would also be a valuable tool for integrated pest control, reducing the need for fungicides and increasing the sustainability of control tools for farmers.