Einkorn (Triticum monococcum) was the first domesticated wheat species, and was central to the birth of agriculture and the Neolithic Revolution in the Fertile Crescent around 10,000 years ago. In new research, scientists generated and analyzed genome assemblies for both the wild and domesticated variety of einkorn. Their results show that around 1% of the modern bread wheat (Triticum aestivum) A subgenome originates from einkorn.
Bread wheat (left) has been bred over thousands of years to have large grain size, and be easy to harvest, but it has lost much of the resilience still maintained in the wild, ancient einkorn wheat (right). Image credit: Kimbra Cutlip / University of Maryland.
Einkorn was the first wheat species that humans domesticated around 10,000 years ago in the Fertile Crescent, a region in the Near East that is often referred to as the Cradle of Civilization.
Wild einkorn was an ingredient of the oldest known bread-like products, baked by hunter-gatherers in modern-day Jordan four millennia before the dawn of agriculture.
Einkorn had a pivotal role in the establishment of agriculture in the Fertile Crescent and it is the only diploid (presence of two complete sets of chromosomes in a cell) wheat species of which both wild and domesticated forms exist.
A noticeable difference between wild and domesticated einkorn is the grain dispersal system.
Wild einkorn has a fragile rachis that facilitates seed dispersal, whereas the rachis in domesticated einkorn is non-brittle.
“Einkorn is still consumed today, cherished for its unique flavor profile and numerous nutritional benefits,” said first author Dr. Hanin Ahmed, a researcher at King Abdullah University of Science and Technology.
“However, its significance in global food production over the millennia has gradually declined as the popularity of bread wheat soared.”
“Bread wheat varieties generally produce higher yields, making them more economically viable for large-scale commercial agriculture.”
“Yet, compared to its wild cousins, modern bread wheat has a reduced genetic diversity — and many breeders are now concerned about how existing crops will fare in the face of climate change and new disease threats.”
“Because einkorn has maintained a larger gene pool, it could hold the genetic secrets needed to develop bread wheat that can continue to feed the world’s growing population.”
By comparing the einkorn genome with the genome of bread wheat, which was successfully sequenced in 2018, Dr. Ahmed and colleagues can look for mismatches, narrowing down the potential targets for genetic traits that differ between the ancient and modern wheat grains.
They sequenced both the domestic and wild variety of einkorn, identifying about 5 billion base pairs that combine to make up individual genes and placing them in the correct order.
“Our genomic analyses now show that the history of wheat is much more complex and involved a lot of mixing and gene flow between different wheat species, including einkorn, which likely grew in close proximity to other wheat varieties, leading to DNA mixing between the two closely related species that remains evident to this day,” said co-senior author Dr. Simon Krattinger, also from King Abdullah University of Science and Technology.
“The most exciting thing about having this genome sequenced is that einkorn is truly a model species that we can use for research, not only as a reference for bread wheat, but other small grains like rye, barley, oats,” said co-author Adam Schoen, a Ph.D. student at the University of Maryland.
“This is the first step. We are not only breeding einkorn genes into bread wheat, but we now have a chance to improve einkorn to make it easier to grow and harvest, because it is healthier and more nutritious than bread wheat,” said co-senior author Professor Vijay Tiwari, also from the University of Maryland.
The findings appear today in the journal Nature.
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H.I. Ahmed et al. Einkorn genomics sheds light on history of the oldest domesticated wheat. Nature, published online August 2, 2023; doi: 10.1038/s41586-023-06389-7
