WASHINGTON – Fruit seeds stored away by squirrels more than 30,000 years ago and found in Siberian permafrost have been regenerated into full flowering plants by scientists in Russia, a new study has revealed.
The seeds of the herbaceous Silene stenophylla plant, whose age was confirmed by radiocarbon dating at 31,800 years old, are far and away the most ancient plant material to have been brought back to life, said lead researchers Svetlana Yashina and David Gilichinsky of the Russian Academy of Sciences.
The previous record for viable regeneration of ancient flora was with 2,000-year-old date palm seeds near the Dead Sea in Israel.
The latest findings could be a landmark in research of ancient biological material, and highlight the importance of permafrost in the "search of an ancient genetic pool, that of preexisting life, which hypothetically has long since vanished from the earth's surface", they wrote.
The study, to appear in Tuesday's issue of Proceedings of the National Academy of Sciences, described the discovery of 70 squirrel hibernation burrows along the bank of the lower Kolyma river, in Russia's northeast Siberia, and bearing thousands of seed samples from various plants.
"All burrows were found at depths of 20-40m from the present day surface and located in layers containing bones of large mammals such as mammoth, woolly rhinoceros, bison, horse, deer, and other representatives of fauna" from the Late Pleistocene Age.
Scientists were able to grow new specimens from such old plant material in large part because the burrows were quickly covered with ice, and then remained "continuously frozen and never thawed", in effect preventing any permafrost degradation.
In their lab near Moscow, the scientists sought to grow plants from mature S Stenophylla seeds, but when that failed, they turned to elements of the plants' fruit, which they described as "placental tissue", to successfully grow regenerated whole plants. -- AFP