The trials were conducted in Horsham and Mildura by the Victorian Department of Primary Industries (DPI)

Project leader, German Spangenberg, said analysis of the crop, grown last year and harvested early this year, confirmed increased crop yields and maintenance of grain size.

"Twenty-four lines of GM wheat were tested and, of those, seven were identified as providing higher yields under drought stress," Professor Spangenberg said.

"Two lines exceeded the yield of the control experimental variety by 20pc."

The results were announced by Victorian Premier, John Brumby, this week at the BIO 2008 conference in San Diego, California.

Mr Brumby said large wheat-producing countries affected by drought, such as Australia, the US, Argentina, China and India, were having to embrace new technologies to continue to meet the demands of the global wheat market.

"These initial results are very promising and suggest that these genetically modified wheat lines may be part of the solution to help farmers maintain and improve their crop yields in a changing global environment," Mr Brumby said.

"Around the world 35-50pc of wheat-growing areas are under drought risk. The number of drought-affected wheat growing areas is likely to increase with the effects of climate change."

However, farmers must face a lengthy wait before the GM cultivars are available commercially.

Drought-tolerant GM wheat lines are some years off consideration for commercial use yet.