Big Yields and Big Gluten-Free Dividends Loom as Science Cracks the Genetic Code of Sorghum

Celiac.com 11/03/2021 - Sorghum is an ancient gluten-free grain thought to be native to Africa. Sorghum is prized for its drought hardiness, and thrives in places where seasonal drought conditions are common, such as northern Australia, where it is the main summer crop. In fact, sorghum is Australia's third largest grain crop. 

Sorghum has a lot going for it. It's high in proteins and minerals. It's naturally gluten-free. Its grains are also notoriously small, which is a problem on numerous levels. Now scientists have cracked the genetic code that will help them grow more and bigger sorghum in Australia, while avoiding genetic modification. 

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Because sorghum grains are small, they are relatively difficult to process. In grains, bigger is better because bigger grain means less husk and more useful amounts of the grain for each kernel. "Those two things together, grain number and grain size, are what makes up yield and sorghum farmers are interested in yield," says UQ professor David Jordan.  "The other reason (grain size) is important is farmers get penalized if they have small grains, because for feeding animals, small grains...don't get broken and that breaking is very important to use the starch that's in that grain."

In the past, when plant breeders tried to grow bigger grains, they got fewer of them. That problem caught the attention of Jordan and his team at the Queensland Alliance for Agriculture and Food Innovation (QAAFI). Jordan and his colleagues, including Research Fellow Dr Yongfu Tao, set out to map of sorghum's genome, looking to find the genes that control grain size, and to separate them from the genes that control for the number of grains. "What we're doing is searching through sorghum lines from around the world that have a range of different characteristics and genes that are not present in elite commercial cultivars," he said.  "Some are very large, double the size of current commercial grains. There's a lot of genetic potential there."

The team mapped the genome and found 125 areas where the DNA sequence was tied to grain size and response to environmental conditions. Mapping the genome and isolating genes responsible for grain size, will allow plant breeders to grow bigger grains while still getting the same number. 

That means that a gluten-free grain crop that is not widely grown, may become much more widespread, and soon be appearing in more gluten-free flours, cereals and pastas.

Read more at ABC.net