Researchers have successfully reconstructed the genetic code of 6,000-year-old barley grains, making it the oldest plant to have its genome sequenced, according to a press release on Tuesday.
Bronze-age barley grains had been found by scientists in a cave in the ancient Masada fortress near the Dead Sea, said the release from Bar-Ilan University near Tel Aviv.
The desert cave in southern Israel is difficult to access and was used only for a short time by humans, probably as a temporary refuge. Ehud Weiss, of Bar-Ilan, said that the region's extreme dryness helped preserve the barley's genetic material for several millennia.
Up to now, only prehistoric corn had been genetically reconstructed.
For the study published online Monday in the Nature Genetics journal, an international research team, which included members from Bar-Ilan and Germany's Max Planck Institutes, used half the found grains for radiocarbon dating, and the other half to extract the ancient DNA.
"For us, ancient DNA works like a time capsule that allows us to travel back in history and look into the domestication of crop plants," said Johannes Krause, director of the archaeogenetics department at Max Planck.
Nils Stein, of Germany's Leibniz Institute, who directed the comparison between the ancient and modern genomes, said: "Our analyses show that the seeds cultivated 6,000 years ago greatly differ genetically from the wild forms we find today in the region."
In contrast, there was "considerable genetic overlap" with present-day cultivated varieties from the region, showing that the domestication of barley in the area was advanced early on, he said.
The similarity between the ancient and modern domestic barley was "amazing" given how much climate, local flora and fauna, and agricultural methods have changed, said Martin Mascher from the Leibniz Institute of Plant Genetics and Crop Plant Research.