Genes of 6,000-year-old barley grains sequenced for first time

Scientists have succeeded for the first time in sequencing the genes in 6,000-year-old barley seeds, making these the oldest plant genome to be reconstructed to date.  The 6,000-year-old Chalcolithic barley grains were retrieved from Yoram Cave in Israel, close to the Dead Sea. Genetically, the prehistoric barley is very similar to present-day barley grown in the Southern Levant, supporting the existing hypothesis of barley

domestication having occurred in the Upper Jordan Valley.  The analysed grains, together with tens of thousands of other plant remains, were retrieved during a systematic archaeological excavation headed by Uri Davidovich, from The Hebrew University of Jerusalem, and Nimrod Marom, from University of Haifa in Israel. The cave is very difficult to access and was used only for a short time by humans, some 6,000 years ago, probably as ephemeral refuge, researchers said. Most examination of archaeobotanical findings has been limited to the comparison of ancient and present-day specimens based on their morphology. Up to now, only prehistoric corn has been genetically reconstructed. In this research, the team succeeded in sequencing the complete genome of the 6,000-year-old barley grains."These archaeological remains provided a unique opportunity for us to finally sequence a Chalcolithic plant genome.

The genetic material has been well-preserved for several millennia due to the extreme dryness of the region," said Ehud Weiss, of Bar-Ilan University.

In order to determine the age of the ancient seeds, the researchers split the grains and subjected half of them to radiocarbon dating while the other half was used to extract the ancient DNA.