FOUR years of research has led to the discovery of genes in barley that may hold the key to breeding larger yielding crops.
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Carried out at the University of Adelaide's Waite Research Institute, researchers used molecular biology and genetic techniques to examine three multiovary barley mutants and discover which genes boosted fertility and made plants more receptive to cross pollination.
While these barley mutants were first discovered in the 1980s, it was the first time the genes responsible for increasing fertility had been identified.
One of the mutants produced up to three times the number of seeds than other plants without compromising its structure.
Researcher Caterina Selva, who has specialised in plant genetics throughout her study and research career, said the discovery had big potential.
"The three mutants looked similar, but the gene that was affected was different in all of them," she said.
"One particular gene, when affected, can give rise to multiple seeds.
"The plant was then able to produce one to three seeds in each flower when it was cross-pollinated.
"This particular mutant has the double advantage of being male sterile, so it doesn't produce any pollen, but it has more female reproductive units, meaning you have increased chances of successful cross pollination."
Dr Selva said sequences obtained from the mutant could be used to modify the flower structure of conventional barley, making it more receptive to hybrid breeding.
"By mixing the mutant with other varieties of barley, we can create stronger, more resilient crops that produce higher yields in even the most challenging of environments," she said.
Hybrid breeding has not been used much in wheat and barley due to the structure of the plants, but is widely used in crops such as maize, rice and cotton.
Dr Selva said the discovery was made using several approaches.
"First we used the microscope to examine how the flowers developed in a normal barley flower and then the mutants," she said.
"That gave an indication of which genetic pathway was affected in the mutant.
"Then we also looked molecularly - looking at the differences in nucleotides between the normal barley plant and the mutants.
"By looking at these nucleotides, we were able to pin down which DNA sequence was affected in the mutant."
Dr Selva said the genetic techniques would need to be field tested and incorporated into breeding varieties before making a commercial impact, but the genetic finding was sound and a step towards facilitating hybrid breeding in wheat and barley.
An associate professor from the University of Adelaide's school of Agriculture, Food and Wine - and senior author of the research published in the Journal of Experimental Botany - Matthew Tucker said these studies on gene mutations was an example of how changing one gene could have a positive impact on grain yields.
"We can overcome barriers to cross pollination by using the more fertile, mutated plants to produce stronger barley and more of it," he said.
"This is even more important in the face of rapid urbanisation, volatile international markets, and extreme weather conditions, which are making growing barley more challenging."
Australia produces more than nine million tonnes of barley a year and it is one of the nation's most widely grown crops, covering about four million hectares of land.
Dr Selva said the finding highlighted the importance of sustained research, saying while they were working with three mutants, only one showed the potential to be used for hybrid breeding.
