Hybrid wheat breakthrough may boost yields

Genome sequencing allowed researchers to pinpoint the gene responsible for sterility, allowing cross pollination

A breakthrough discovery by Australian researchers is making it easier to bring hybrid wheat to farmers.

Researchers at the University of Adelaide found a naturally occurring gene that, when turned off, eliminates self-pollination and allows for cross pollination in wheat plants.

“That is the core element for being able to do hybrid breeding,” said Ryan Whitford, hybrid wheat program leader at the University of Adelaide.

“You need to do cross pollination en masse, like at a commercial scale.”

Wheat is a self-pollinating crop but the university had mutant lines of wheat that were male sterile and able to cross pollinate.

The challenge was identifying which gene in those plants was responsible for the sterility.Re-searchers have been trying to do that since the 1960s.

The tool that made it possible was the sequencing of the wheat genome.

But it still took more than four years to find the elusive gene due to the complexity of the wheat genome.

The gene has been incorporated into DuPont Pioneer’s hybrid wheat program.

“Wheat genetics are very complicated,” Marc Albertsen, DuPont’s research director, said in an email.

“The Ms1 gene is unique in that it functions as though it were in a simpler genetic background.”

Wheat genes typically require variants in three pairs of chromosomes to exhibit an altered trait. In Ms1, only a single pair of chromosomes was required.

DuPont is using the gene in its Seed Production Technology (SPT) hybrid breeding system.

“Cloning this gene has enabled the use of SPT, a superior system for producing hybrid wheat that does not limit the breadth of potential parents that could be used to produce the most productive hybrids possible,” said Albertsen.

DuPont hopes to commercialize hybrid wheat in the next 10 years. Syngenta hopes to have its hybrid wheat on the market by 2020.

Whitford said European companies have used chemicals to induce male sterility in wheat plants but if they get the dosage wrong or wind or rain disrupts the process, it results in poor quality hybrid seed.

“That is really a commercially risky approach,” he said.

Using genetics to introduce male sterility ensures large-scale cross pollination and good quality hybrid wheat seed that is no different than corn and canola hybrids.

Whitford said the technology is classified as a new breeding technology and does not result in genetically modified seed being sold to farmers or consumers.

Wheat yields have lagged far behind corn yields, growing by slightly more than one percent a year.

The hope is that hybrid wheat will provide a 10 to 15 percent yield boost over conventional varieties.

“I will be really excited when this is actually used and getting out to the growers,” said Whitford.

Hybrid seed loses its effectiveness after one generation, so farmers can’t save the seed for next year.

That means increased return on investment for wheat breeding companies, which in turn will lead to more research and development expenditures, he said.

“They will be able to make greater yield gains and try and catch up to what has been seen in corn.”

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