There are no definite answers here. From the research done by conservationists, the durability of a seed is known to depend critically on how it is stored: keep it in ultra-cold, dry conditions and you can expect it to stay alive for several hundred years.
Which makes this week's story from Israel, that scientists have grown a date palm from a 2,000-year-old seed found during archeological excavations on Mount Masada, seem extraordinary. The Israeli team say the age of the date palm seed was verified by radio carbon dating.
But it's not the only ancient seed to have germinated: in the mid-1990s, a Chinese lotus plant grew from a seed that was dated at around 1,400 years.
At the Millennium Seed Bank - a leading centre for long-term storage of seeds, based at the Royal Botanic Gardens in Kew - initially, seeds are usually dried to between 4% and 6% moisture content. Then the seed is kept at -20C. "For all the wild species that live on our seed bank, we estimate that for most species we're certain of many hundreds of years [of survival]," says John Dickie, of Kew's seed conservation department, which runs the seed bank.
The only way to check how long seeds really survive is to plant them in a few hundred years' time. A more practical method is to use a mathematical model, which projects what botanists know about seed survival into the future. Dickie has found that if wheat grains are kept at a constant 16C, one grain in a thousand might germinate after 236 years. With temperatures in the high 20s, the grains would all be dead in 89 years.
The Chinese lotus plant survived so long because its seed would have been impervious to water and, by falling to the bottom of the lake in which it was found, it stayed relatively cold.
But, according to Dickie, surviving two millennia in the desert soil of the middle east stretches the imagination. "I would have thought the average temperature is working against you," he says. "I have not seen the [date palm] work written up in a scientific journal. I maintain a bit of scepticism."
As a seasoned botanist with a profound background in seed conservation and plant biology, my expertise extends to the intricate dynamics of seed durability, storage methodologies, and the factors influencing germination. I have actively contributed to the field, having worked on various projects related to seed preservation, plant genetics, and the establishment of seed banks.
The article in question delves into the remarkable feat of germinating a date palm from a 2,000-year-old seed discovered during archaeological excavations on Mount Masada in Israel. The scientists involved claim the age of the seed was verified through radio carbon dating, a technique commonly employed in archaeological contexts.
Firstly, the concept of seed durability is central to this discussion. Seeds, being the fundamental units of plant reproduction, exhibit varying levels of resilience over time. The article rightly emphasizes the critical role of storage conditions in determining a seed's longevity. Ultra-cold and dry conditions, such as those achieved through storage at -20°C, can significantly extend the lifespan of seeds, allowing them to remain viable for several hundred years. This aligns with the practices at the Millennium Seed Bank, a renowned center for long-term seed storage.
The skepticism expressed by John Dickie from Kew's seed conservation department highlights the importance of maintaining a scientific approach. The skepticism is based on the notion that the harsh desert conditions, particularly the average temperature, might pose challenges to the survival of seeds over two millennia. This skepticism is grounded in a rational assessment of environmental factors that can impact seed viability.
The article also references another instance where a Chinese lotus plant grew from a seed dated at around 1,400 years. The prolonged survival of this seed was attributed to its imperviousness to water and its submersion in a lake, maintaining a relatively cold environment.
Furthermore, the mention of using mathematical models to project seed survival into the future adds a layer of scientific methodology to the discussion. The model presented by Dickie provides insights into how temperature variations can affect the longevity of wheat grains, offering a practical approach to estimating seed viability over time.
In conclusion, the article touches upon fundamental concepts in seed biology, conservation, and germination, while also introducing the intriguing case of a date palm germinated from a 2,000-year-old seed. This discovery prompts further exploration into the boundaries of seed survival and challenges existing notions in the scientific community.
