Researchers may be close to developing high-yielding “elite wheats” with increased resistance to crown rot, a disease which costs the industry close to $100 million a year.
Researchers at the University of Southern Queensland in Toowoomba, supported by the Grains Research and Development Corporation (GRDC), have been trawling through the chromosomes of several wheat lines that show resistance to the fungal disease.
They hope they have finally unlocked their secret, identifying between three and five genetic regions in each line that work together to create resistance.
These key genetic regions are now being incorporated by commercial breeding companies into the DNA of high-yielding varieties to create adapted, high-yielding wheats, which will reduce losses due to the disease and be highly desirable to farmers due to an improved “bottom line”.
Leading the research is Professor of Molecular Plant Sciences Mark Sutherland, who said the research was at an exciting stage, with the most recent field trials showing promising early results.
He was hopeful the first of the adapted wheat germplasm could be available to commercial wheat breeding companies in three years to be used in commercial variety development, although he stressed that the research was still a long way from complete and results were not yet guaranteed.
“We are as confident as you can be when you are dealing with the difficult genetic systems present in wheat that we are on the right track,” Prof. Sutherland said.
Crown rot, (Fusarium pseudograminearum), is a destructive fungus that causes an estimated $100M damage to Australian wheat and barley crops each season and can devastate individual crops.
Prof. Sutherland said the first step in finding a solution was identifying lines of wheat with significantly better resistance, however these were five low-yielding, unadapted wheat germplasm that did not grow well in Australian conditions.
“The aim then was to get this resistance into lines of wheat adapted to Australia possessing other traits that farmers require,” Prof. Sutherland said.
“After we successfully cross an unadapted resistant line with a susceptible variety, we screen the plants in subsequent generations for the presence of genetic markers linked to the resistance, to identify those lines most likely to express the desirable trait.
“Keeping these genes together in subsequent generations when the line is crossed to an elite but susceptible breeding line, is a bit like herding cats.
Paddock trials of potentially resistant wheats were recently harvested and are currently being rated for disease symptoms, yield and the presence of the genetic markers.
“We have already been able to discern differences in the paddock in small experimental rows, with crown rot much more obvious in the populations without resistance,” Prof Sutherland said.
“Now we have to demonstrate whether the more resistant lines maintain their resistance across multiple large plot yield trials in different cereal growing environments across several states.
“The research is certainly at an exciting stage.”
Caption: Crown rot, (Fusarium pseudograminearum), is a destructive fungus that causes an estimated $97M damage to Australian wheat and barley crops each season and can devastate individual crops.
Mark Sutherland, Professor of Molecular Plant Sciences, University of Southern Queensland
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