Wheat breeding genetic research and development for high yield varieties

Dr Viridiana Silva-Perez from the Australian research Council Centre of Excellence for Translational Photosynthesis using the new hyperspectral reflectance tool. Photo Charles Tambiah.

Wheat researchers have developed a gene discovery technique which may pave the way for breeding programs to deliver the next generation of high performance crops.

The new hyperspectral reflectance technique is essentially a phenotyping tool which uses a new methodology that both speeds up the process and delivers new, valuable genetic information.

“We measure the colour of light reflected from leaves, which contains information about many leaf properties, including photosynthesis, the process by which plants transform sunlight and carbon dioxide into sugars,” said lead researcher Dr Viridiana Silva-Perez.

The new methodology was published in a recent study in the Journal of Experimental Botany.

Discovering genetic information in wheat is a mammoth undertaking. Wheat genes contain 40 times more base pairs than rice and six times more than a human

The new methodology enables “measurement of many plants to map populations and identify useful genes for improving crop production,” Dr Silva-Perez said.

She works with the ARC Centre of Excellence for Transnational Photosynthesis, which is aiming to deliver the next step change in cropping, following the high-yielding dwarf varieties from Norman Borlaug’s green revolution.

Australian National University Professor John Evans, a chief investigator at the ARC Centre of Excellence for Translational Photosynthesis was another author of the study.

“It will allow rapid discovery of genetic markers associated with photosynthetic traits that can be introduced into the wheat breeding pipeline,” explained Mr Evans, another of the study’s authors.

“The outcomes from the Green Revolution were maximised by breeding. To continue to grow crop yields we need to increase biomass and that is dependent on photosynthesis.

“Up to now, a sticking point has been how to measure photosynthesis and get at plant genetics. The new methodology allows breeders to select for photosynthetic characteristics.”

Mr Evans said conventional techniques take 20 minutes per leaf to get at part of the information provided by the new method, which can be used to analyse up to 100 measurements an hour.

The new tool allows scientists to measure the size of a “engine” in a plant’s cell.

“It permits us to ask very useful questions about what is happening inside the plant, for example, if the plant can get more carbon for the water it spends,” he said.

The new technique was field tested on wheat in Australia and Mexico and has since been used on other crops including corn, rice and sorghum in Australia, the UK and USA

Funding for the research was funded by the Grains Research and Development Corporation (GRDC), the Australian Research Council Centre of Excellence for Translational Photosynthesis, MasAgro – a partnership between CIMMYT and Mexico, CSIRO and Australian National University.