Scientists Grew Palm Trees From 2,000-Year-Old Seeds
Judean dates were once renowned for their size and flavor
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In ancient times, the region of Judea was known for its plump, delicious dates, which delighted the palates of classical writers like Pliny the Elder; in his sweeping natural history treatise, the Roman author marvels at the Judean date’s “unctuous juice” and “extremely sweet sort of wine-flavour like that of honey.” The palm trees that bore these tasty fruits eventually died out—but now, researchers in Israel have brought them back to life.
As Alice Klein of New Scientist reports, a team led by Sarah Sallon of the Louis L. Borick Natural Medicine Research Center in Jerusalem has sprouted six new trees from the 2,000-year-old seeds of Judean date palms, discovered at various archaeological sites. The trees were once “grown in plantations around Jericho and the Dead Sea,” the researchers explain in Scientific Advances. By the 19th century, following years of warfare, “no traces of these historic plantations remained.”
Seeds of the Judean palm have, however, survived for millennia—possibly due to the unique environmental conditions of the area around the Dead Sea, which is situated 1,388 feet below sea level. Precipitation and humidity there are low, and the region boasts the thickest atmosphere on Earth, which might protect ancient relics from cosmic radiation, according to the researchers.
In 2008, Sallon and her colleagues announced that they had germinated a 1900-year-old date seed discovered at Masada, an ancient fortification located high above the Dead Sea, where Judean rebels took a dramatic stand against the Romans in 73 or 74 A.D. According to Sarah Zhang of the Atlantic, the researchers named that tree Methuselah, after a biblical figure who lived to the age of 969.
The success of the experiment took Sallon by surprise—“I was so not expecting it,” she tells the Atlantic—and she and her team had not taken basic measurements, like seed weight or size. They decided to give the project a more systematic try, with 34 seeds found at various archaeological sites around the Judean desert, including Masada and Qumran, the site where the Dead Sea scrolls were discovered.
The seeds were soaked in water, supplemented with hormones that encourage germination and rooting, and planted at a kibbutz in southern Israel. Of the 34 seeds, six eventually sprouted, four male and two female. (Male date palms produce pollen, and females produce flowers.) They too were given biblical names: Judith, Hannah, Uriel, Jonah, Boaz and Adam.
Because Judith and Hannah have not yet reached sexual maturity, the researchers haven’t been able to produce any ancient Judean dates. They do note, however, that the ancient seeds were wider and longer than those of modern varieties, their large size suggesting that they came from domesticated crops. In fact, as New Scientist notes, genetic analysis of the seeds revealed that some of them came from female date palms that had been pollinated by male palms from different regions.
“Our results reinforce the historical narrative that a highly sophisticated domestication culture existed in ancient Judea,” the researchers write. “Local farmers with an interest in maintaining genetic diversity in their date plantations ... used cross-breeding with foreign (genetically different) males to develop a rich collection of varieties.”
This surprising experiment could prove useful to today’s date farmers, because introducing ancient genes to the modern genetic mix may help protect date palms against factors like climate change and pests. “These ancient seeds might represent lost genetic diversity we don’t see any more,” Oscar Alejandro Pérez-Escobar of the Royal Botanic Gardens Kew, who was not involved in the research, tells the Atlantic.
When the time is right, Sallon and her colleagues hope to use ancient male seedlings to pollinate ancient females. The fruit might not taste the same as the Judean dates eaten thousands of years ago; as the Atlantic notes, “Sexual reproduction—crossing a male and female tree—scrambles genetic lineages and introduces uncertainties.” But according to the study authors, resurrecting these sweet treats of yore will help scientists “more fully understand the genetics and physiology of the ancient Judean date palm once cultivated in this region.”