Researchers find new varieties of wheat needed to resist global warming trends

Some of Australia’s most popular wheat varieties cannot withstand the global warming trend, and new varieties will be needed before too long, according to a new study from the University of Sydney.

Professor Daniel Tan undertook the research and said wheat varieties susceptible to heat stress produced significantly lower yields, suggesting that more careful plant breeding and selection was urgently needed.

Researchers from the University of Sydney’s Plant Breeding Institute tested 23 varieties of Australian wheat at 35 degrees Celsius and higher CO2 levels.

Common wheat varieties tested include Suntop – one of the most widely adapted wheat varieties on Australia’s east coast – and Mace and Scepter in Western and South Australia.

“We looked at all 23 popular strains using a heat and carbon test, and when you hit them with any of the key factors, especially during flowering, the result was a reduction in yield,” Mr. Tan said.

“I think in 2018 and 2019, and doing it in the middle of the drought before that, we saw the impact of heat and CO2 on the wheat crop.

It was very obvious that we were getting the worst effects, and there’s also this long hot period in the spring where you had very high temperatures resulting in very little pinched grain and the processes of the plant shutting down because of the heat.”

Researchers examined 23 popular varieties using a heat and carbon test.( Provided: University of Sydney)

Focus on better resilience

Professor Tan said it was important for the grain industry to develop new varieties of wheat that can withstand heat better.

“We need more new varieties of wheat because it’s better to have a range of options,” he said.

“It’s a bit concerning because the next 10 to 20 years could even be a few degrees higher than predicted for global warming, and that’s happening faster than predicted, so we’re trying to get some new varieties in the pipeline to take care of then.”

Finding and developing more resilient varieties would be a priority for the future.

“It depends on the year, but it takes a wheat [variety] which could be resilient. You have to have that resilience in your variety physically,” Mr. Tan said.

“Our goal was not to create a very high yielding variety that can withstand high temperature, but we need a variety that can maintain its yield despite the high temperature.

A greenhouse with wheat growing inside.
Researchers say now is the time to develop more resistant wheat varieties.(Provided: University of Sydney)

Teresa H. Sadler