Wheat varieties with improved resistance and tolerance to the devastating crown rot disease are edging closer to commercial reality following significant industry investment in pre-breeding research.
The Grains Research and Development Corporation (GRDC) has been investing in pre-breeding programs at the University of Sydney’s Plant Breeding Institute (PBI) at Narrabri for more than five years, enabling researchers to assess the performance of individual breeding lines under crown rot conditions.
One of PBI’s leading research fellows, Dr Philip Davies, said a phase of pre-breeding research had recently been completed which would allow germplasm with enhanced crown rot tolerance and resistance to be delivered to commercial breeding companies.
“This is where we go and look for sources of resistance in either wild relatives of wheat, land races from overseas or bringing the resistance in from overseas cultivars and then make them more agronomically adaptable to the region. These sources can then be passed onto the breeding companies,” he said.
“At the same time, the material we have already made available to breeding companies is making its way through the breeding cycle and will hopefully make it into growers’ paddocks in the next seven or eight years.”
Dr Davies’ extensive work within the GRDC-funded crown rot pre-breeding research recently saw him named winner of the prestigious 2016 GRDC Emerging Leader Award, which was presented at today’s GRDC Grains Research Update in Narrabri.
Crown rot is caused by the fungus Fusarium pseudograminearum and is one of the most serious disease threats to winter cereal crops in Australia costing northern growers around $80 million on average each year.
While the current research is ground breaking and promises to save millions of dollars in crop yield in the longer term, Dr Davies said genetic improvement was unlikely to offer a `silver bullet’ to growers in terms of complete varietal resistance and tolerance.
“The work looking at altering management practices has made huge gains in the level of risk that growers can manage as well as the losses that are experienced,” he said.
“But management alone or genetics alone is never going to be the answer. It needs to be a blend of both.
“The GRDC investments are reflecting that – there’s been significant investment in a national crown rot management project led by NSW Department of Primary Industries (DPI) cereal plant pathologist Dr Steven Simpfendorfer looking at crop rotations, operations between crops like inter-row sowing, nitrogen management and weed management in fallow.
“That work combines with the pre-breeding work in resistance and tolerance, and eventually commercial breeding, to bring resistance sources to the market.”
Resistance centres on the ability of a plant to halt the invasion or progression of pathogen infection while tolerance is the physiological response of a plant which enables it to mitigate yield loss in spite of pathogen infection.
“With crown rot, you are never going to get absolute resistance – there’s no such thing as a plant that is immune to crown rot simply because of the way the pathogen works and interacts with the plant,” he said.
“So we are always going to have to look for those partial sources of resistance and tolerance so the plants can escape yield loss.
“And that’s the real focus of the pre-breeding program here - looking for yield under crown rot whether that’s through resistance or tolerance.”
To see Dr Davies discussing the crown rot pre-breeding program, visit the GRDC YouTube channel or follow this link.
Dr Philip Davies, Research Fellow, PBI
02 6799 2244/0403 613974
Sarah Jeffrey, Senior Consultant Cox Inall Communications