New genes for an old breed

A new breeding strategy that involves the transfer of genes looks set to produce new wheat strains that are resistant to stripe rust and pre-harvest sprouting, and fast.

Developed by researchers at the University of Queensland, the new breeding strategy reduces development time from more than 10 years to just two-and-a-half years. That means fast-maturing, high-yielding wheat varieties develop in less than half the time.

“Pending the performance of the wheat lines, we reckon that this new wheat variety with high-yield potential, resistance to stripe rust and pre-harvest sprouting tolerance could be available to southern growers in less than four years,” said Dr Lee Hickey from UQ’s Queensland Alliance for Agriculture and Food Innovation.

In collaboration with his PhD supervisor Dr Mark Dieters, Hickey used a novel approach to transfer multiple genes for resistance to stripe rust and grain dormancy into the Australian wheat cultivar H45.

H45 was a successful wheat variety released in the 1990s that was adopted by growers in Victoria and NSW and then abandoned because of its susceptibility to current strains of stripe rust.

As with all Australian wheat varieties, H45 also lacks adequate grain dormancy to protect it against pre-harvest sprouting; that is, germination of grain in the spike that occurs in response to rainfall at crop maturity - which results in crops being downgraded, bringing in less money for growers.

Field trials

Field trials are currently being conducted in Victoria and New South Wales and the technique is expected to start providing benefits to farmers within the next few years.

The UQ geneticists are working with the Ballarat, grower-owned, seed company GrainSearch.

“We developed 84 wheat lines, each 90 to 95% genetically similar to the H45 variety, but with multiple genes for resistance to rust and pre-harvest sprouting,” Dr Hickey said.

“There are no wheat varieties available to Australian growers that offer adequate protection against pre-harvest sprouting, so this would be a first.

“The population also displays useful variation in physiological characteristics, including days to flowering, maturity, spike length, leaf width, seedling vigour and grain size.

“These characters will be important for determining which line becomes the new wheat variety.”

The UQ team has used the same techniques to rapidly produce disease-resistant strains of barley.

The researchers are working with breeding companies and seed companies across Australia and overseas to speed up grain improvement techniques.

GrainSearch was formed in 2002 by a small group of innovative grain growers. It has grown to become the largest grower-owned seed company in Australia, with more than 200 grower-based shareholders. Their primary objective is to seek out, through the latest research and development techniques, new varieties of seed that significantly improve the productivity of shareholders, farming businesses and agricultural enterprises.