Australia
October 17, 2008
Key points:
• GRDC-funded project delivers new sources of rust resistance to
breeders
• Diversity in resistance sources critical to providing robust
defence against emerging rust pathotypes
• Australia in ‘excellent’ position to defend against stem, leaf
rust
University of Adelaide
researchers have identified new sources of stem and leaf rust
resistance in wild grass relatives of wheat sourced mostly from
the ‘fertile crescent’ of the Middle East.
The research project, supported by growers and the Australian
Government through the Grains
Research and Development Corporation (GRDC), has helped
position the Australian grains industry to better defend against
emerging rust races such as the virulent Ug99 stem rust
pathogen, which scientists believe may pose a serious threat to
global wheat supplies.
Project supervisor Dr Ian Dundas, of the School of Agriculture,
Food and Wine at the University of Adelaide, said the project
was part of a concerted global effort helping to underpin the
sustainability of wheat cultivation.
“Australia is in an excellent position to combat the threat of
cereal rust,” Dr Dundas said. “This is one of many projects
under the Australian Cereal Rust Control Program (ACRCP)
developing new sources of rust resistance for growers.
“Nearly two decades ago, the ACRCPAustralian research
organisations and GRDC recognised the danger to the economic
viability of Australian wheat producers from the emergence of
new strains of rust and began investing heavily in this type of
research. In the long term, this work will assist Australia’s
competitive advantage in the global market place.
“Finding alternative sources of resistance is vitally important.
Diversity in resistance genes and variation in sources of
resistance is one of our best defences when confronting any new
rust pathotypes.”
The project has involved working with wheat breeding lines which
contain chromosome fragments from uncultivated relatives of
wheat.
“These are mostly wild grasses from the region in the Middle
East where modern bread and durum wheat species originated,” Dr
Dundas said. “The fertile crescent is a centre of genetic
diversity.”
In a recent project, Dr Dundas’ team has identified three new
sources of stem rust resistance from the species Triticum
speltoides, and two new sources of leaf rust resistance from the
species Triticum searsii and Triticum tripsacoides.
Plant pre-breeding is not a fast process. Dr Dundas said there
was considerable work to be done before the newly identified
genes found their way into wheat varieties for Australian
growers.
“Provided the resistance sources meet our expectations, we could
see them in wheat varieties within the next 10 years,” he said.
“An important step will be testing wheat breeding lines with the
newly identified resistance genes in the field. We’ve been
working with scientists in the United States, where they will
test these lines for resistance to the Ug99 stem rust pathogen.
“This virulent form of stem rust was identified in Uganda in
1999 and has now spread into the Middle East.”
The GRDC is a major investor in the fight against cereal rust
and part of a world-wide collaboration of scientists working to
overcome the threat of Ug99. The GRDC said immediate priorities
for effective rust management were growing resistant wheat
varieties, managing the ‘green bridge’ of volunteer growth, and
responding to outbreaks with strategic fungicide applications.
Growers can access detailed information about rust management by
visiting
www.grdc.com.au/rustlinks.
Other news
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