DNA fingerprinting helps track stored grain "superbugs"
University of Queensland researchers are using DNA fingerprinting to track down fumigation-resistant "superbugs" which each year threaten 40 million tonnes of stored grain and stand in the way of an additional $900 million in premium quality grain sales for Australia.
Industry experts believe controlling the stored grain beetles would boost sales of premium quality grains, those free of both pests and chemical residues, from $400 million to $1.3 billion annually, significantly boosting Australia's current $6 billion industry.
The bonanza depends on controlling insects which have recently been found to have resistance levels 235 times greater than normal to the cost-effective and environmentally-safe phosphine fumigant which is currently the only suitable control method.
Dr Paul Ebert, Dr Paul Reilly and PhD candidate David Schlipalius, researchers in the UQ Biochemistry Department, are working on the project with the Grains Research and Development Corporation (GRDC) and the Farming Systems Institute (QDPI), with support from Grainco Australia, one of the country's major grain storage providers.
The UQ researchers are the only group in the world tracking the resistance genes in the pest. The development of a rapid and reliable DNA fingerprinting procedure which readily identifies insect genotypes represents a major advance in the project.
"The fingerprints help us to find (map) the genes that make the beetles resistant. Knowing how the genes work will help us to devise strategies to kill the beetles," Dr Ebert said.
"The fingerprints, with some improvements, will also let us quickly identify the super-resistant beetles. A company like Grainco will use this information to tailor the dose of fumigant to the resistance profile of the pests."
The "superbug" problem came to the attention of UQ graduate Dr Patrick Collins of the Farming Systems Institute, leader of a GRDC-funded national project to monitor phosphine resistance in stored grain pests, two years ago.
While Dr Collins has been able to monitor resistance levels among insects, there is no early detection system that allows either him, farmers or grain storage companies to respond to the "superbugs" before a control failure. In addition, little information exists on which to develop a test, as neither the mode of phosphine action nor the basis of resistance is known.
"Control of stored grain pests is particularly difficult in countries with moderate climates, such as Australia, because insects are able to breed throughout the year," Dr Ebert said. "We are competitively disadvantaged relative to our major competitors in the lucrative premium grains market because they have much harsher climates that naturally limit pest populations."
The project is a prime example of the application of fundamental research to 'real-world' problems of regional and national significance, and is particularly appropriate in a political climate in which universities are encouraged to be responsive to regional needs, Dr Ebert said.
For further information, contact Dr Ebert on (07) 3365-2973.
