New insights into the genetic origins of wheat could help inform changes that improve its ability to fight off diseases, scientists say. Photo by Bru-nO/Pixabay
Nov. 1 (UPI) -- Modern wheat bread may have originated in the Caucuses region of present-day Georgia in eastern Europe, a study published Monday by Nature Biotechnology found.
After sequencing the DNA from 242 unique accessions of Aegilops tauschii, a wild relative of bread wheat, collected from areas of Turkey and Central Asia, the key ingredient appears to have been first cultivated about 300 miles from the so-called Fertile Crescent, the researchers said.
The Fertile Crescent is the region of the Middle East stretching across Iraq, Syria, Lebanon, Palestine, Israel, Jordan and Egypt that scientists consider to be the birthplace of modern civilization because the land provided a vibrant source of food, according to the researchers.
The discovery was made as part of an international research project seeking ways to improve wheat crops globally, and making the crop more like some of its ancestors could make it less susceptible to disease, they say.
"The discovery of this previously unknown contribution to the bread wheat genome is akin to discovering the introgression of Neanderthal DNA into the out of Africa human genome," researcher Kumar Gaurav said in a statement.
"This group of Georgian accessions form a distinct lineage that contributed to the wheat genome by leaving a footprint in the DNA," said Gaurav, a postdoctoral scientist at the John Innes Center in Norwich, England.
The newly discovered lineage may have been more geographically widespread in the past and it may have become separated during the last ice-age, he and his colleagues said.
The origin of modern hexaploid bread wheat, which accounts for 95% of all cultivated wheat globally, has long been the subject of intense research, with evidence suggesting that it was cultivated 10,000 years ago in the Fertile Crescent.
It is a complex combination of different grasses with a sizable genetic code, according to the researchers.
Through a combination of natural hybridizations and human cultivation, Aegilops tauschii contributed to the genome of hexaploid wheat, adding the properties for making dough and enabling it to flourish in different climates and soils.
However, domestication, while increasing crop yield, came with a cost: eroding genetic diversity that gave wheat protective traits against disease and heat.
Indeed, the analysis by Gaurav and his colleagues revealed that just 25% of the genetic diversity present in Aegilops tauschii made it into hexaploid wheat.
Additional experiments showed that it is possible to transfer genes for a subset of these protective traits into modern wheat, using a library of synthetic wheats, to create a specially bred wheat that incorporates Aegilops tauschii characteristics, the researchers said.
Ancestral Aegilops tauschii DNA found in modern bread wheat includes the gene that gives superior strength and elasticity to dough, according to the authors of a companion analysis published Monday by Communications Biology.
"We were amazed to discover that this lineage has provided the best-known gene for superior dough quality," co-author Jesse Poland, professor of plant pathology, at Kansas State University, said in a press release.