Race on for new wheat breeds

With one fifth of the world's food needs dependent on the 200 million hectares of wheat which grows worldwide, any yield decline due to climatic factors could be disastrous.

Although wheat's global yield rose 20 per cent from 1987 to 1997, a one per cent decline from 1997 to 2007 flagged that wheat production would struggle to sustain the escalating global population, which is likely to rise from seven billion to nine billion by 2050.

As climatic conditions across Australia's wheatbelts change, atmospheric carbon dioxide concentration and temperatures rise and rainfall lessens, a significant challenge confronts wheat breeding programs as they race to bring on new adapted varieties.

Leading the way in assessing the challenge and finding a way to combat it is CSIRO Plant Industry and the University of WA's institute of agriculture, which are working together at UWA's Shenton Park Field Station to inform wheat breeders about how climate change and variability will affect the genetic traits they select for.

A research collaboration of UWA institute of agriculture director Kadambot Siddique, Helen Bramley, of UWA, and Jairo Palta, of CSIRO and UWA, is evaluating the impact of the interaction between elevated carbon dioxide, high temperature and terminal drought on high-yielding traits of wheat.

Another component will identify wheat genotypes with efficient root-to-shoot signalling patterns associated with response to water stress, using pots to manipulate moisture in the rhizosphere.

According to Professor Siddique, evaluating how wheat crops respond to changing climatic conditions will help quantify the impact of climate change and identify possible improvements.

"While studies into the impact of future climate change have so far focused on the effects of increasing average temperatures or carbon dioxide levels independently, climate change models predict that in southern Australia the increase in carbon dioxide concentration, temperature and incidence of terminal drought will occur simultaneously," he said.

"It is crucial that we quantify how wheat genotypes respond to these factors, backed up with accurate data, so that we can ensure a sustainable future for wheat production through improved varieties, efficient decision support systems and innovative agronomic packages.

"Our research will generate new information relevant to wheat physiology and breeding strategies to help in the development of future water efficient wheat varieties.

"The results will allow wheat breeders to select traits to best respond to the changing climate."

Outputs generated by the research include:

·Wheat lines/varieties identified with greater yield and grain quality under the predicted future climate.

·A new method to directly monitor leaf hydration that will assist wheat pre-breeding scientists and breeders select drought and high temperature tolerant germplasm.

·The molecular basis for changes in water use under climate change identified and this information to be used to develop molecular markers.

·New information about hydraulic mechanisms affected by water deficit and high temperature under climate change relating to grain development, stomatal response, plant hormone signalling and root architecture as a trait to produce improved yield under terminal drought.