Breeding key to canola heat tolerance

Peter MilneCountryman
UWA plant breeding researcher Professor Wallace Cowling.
Camera IconUWA plant breeding researcher Professor Wallace Cowling. Credit: UWA

Climate change will drive down canola and wheat yields unless lessons from animal breeding can speed the development of greater drought and heat stress tolerance, according to a UWA researcher.

UWA plant breeding researcher Wallace Cowling, who will talk at the AusCanola conference in Perth this week, said global temperatures were predicted to rise by between one and four degrees Celsius this century, and what were now one in 20-year events could become annual events in 50 years.

“The modelling suggests that traditional plant breeding can’t keep pace with the climate and get yield and heat and drought tolerance and disease resistance,” he said.

His research showed heat and drought-tolerance traits could be bred for, but they had low inheritability.

“We have to have some very good methods for selection otherwise we’ll miss it,” he said.

His team is one of a handful around the world turning to techniques long used in animal breeding.

He said plant breeders were inclined to improve one trait at a time, which was a mistake.

“We’re proposing a method that comes out of animal breeding, and it allows us to select for all of these economic traits in what animal breeders call an economic index,” he said.

Borrowing from techniques used by sheep breeders, they would use decades of data in their analysis and plan their work ahead. “The animal breeders optimise matings to get the best long-term genetic progress, and we’re going to use the same software,” he said.

Applying these animal breeding techniques to canola could allow his team to complete a crossing and selection cycle in two years instead of the six to eight years common in traditional plant breeding.

Canola and wheat are most susceptible to heat and drought while flowering.

“Even if there is no drought a couple of days above 30 degrees and you will cause a major reduction in final yield of canola,” he said.

“You throw in drought on top of that and ... you’ve got the recipe for a disaster for crop yields.”

Professor Cowling said areas of central NSW last year during the flowering of wheat and canola had their first September days recorded above 30C.

“This caused a major reduction in yield to the point that many farmers just cut their canola and wheat for hay,” he said.

The next step for the UWA team is to attract funding for trials to verify their modelling and before a larger-scale breeding program kicked off.

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