Noah’s Ark of Plants. “An insurance policy for the future”

Noah's Ark of Plants.  "An insurance policy for the future"


South of Londonin the heart of the English countryside, between rolling hills and honey-colored houses, stands the Millennium Seed Bank, the largest seed bank in the world, ranging from the palms of Madagascar to the tundra of Alaska. Opened in 2000, the facility, which receives public funding and donations, was started by the Kew Gardensthe Royal Botanic Gardens. It preserves 2.5 billion seeds, which belong to over 40,000 species from 190 countries, equal to about 20% of the world’s flora.

“Perhaps the most important conservation initiative ever undertaken,” says the documentary maker David Attenborough. At the headquarters, priorities are the endangered plantswhich, according to scientists, would even be two out of five speciesespecially threatened by the change of use of agricultural land and come on climate changes. To the plants at risk are added those present only in a specific geographical area and those useful from a food or therapeutic point of view.

The first stages of processing

The new seeds, collected by collaborators in special partnerships and by the bank’s own scientists during field work, arrive at the facility wrapped in cloth or paper bags. Once unpacked, they are taken to the initial drying chamber, similar to an aircraft cabin, maintained at a temperature of 15°C with a relative humidity of 15%. This phase, which lasts from two weeks to six months, is capable of extending the life of the seeds by 40 times. The latter, after being cleaned by hand or using a vacuum cleaner to remove plant debris, are subjected to quality testing, which includes an X-ray analysis to identify and discard damaged, insect-infested or empty specimens. At this point, the selected seeds are introduced into the main drying chamber, which operates at 18°C ​​with 15% humidity. To avoid dehydration, staff are allowed to work in this area for up to two hours.


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The underground vault

In the next stage, the seeds are placed in labeled glass jars, so that each one has its own identity card, which indicates the name of the plant, the country of origin, the date of arrival in the bank. Thus, conservation can begin in the underground vault, large enough to contain 33 buses, in one of the six freezing chambers, at a temperature of -20°C. These cells are all armored, flood-proof, bomb-proof, radiation-proof, and energy-efficient, powered by solar panels.

From orchids to rare plants

Scientists monitoring the collections, intended to be kept for decades, possibly centuries, enter these rooms in overalls and gloves, as if ready for an expedition to the North Pole. They take a look at the very numerous seeds of the orchid family, without neglecting those of rare plants, such as the smallest water lily in the world or Deschampsia antarctica, a plant native to the frozen continent. ‘Every ten years the frozen specimens are removed and tested to see if they can still successfully germinate,’ says Professor John Dickie, project manager. “Seed collections are generally stored not only in the Seed Bank but also in their country of origin. A duplication that increases security and makes them more accessible.

The research laboratories

Alongside the seed collections, there are biology laboratories. Here the experts deal, for example, with the so-called recalcitrant seeds, possessed by one plant species out of ten, that is, which cannot be dried and, therefore, preserved with conventional methods. Research is therefore underway to develop new storage systems. One of these is cryopreservation, in which the seeds, or parts of them, are dried very quickly and then frozen using liquid nitrogen, at -196°C. But the challenges don’t end there. “There is still a lot of work to be done, thousands more species need to be collected and added to the vault,” Dickie announces. “Faced with so many endangered plants, we need an insurance policy for the future, one that helps the green heart of our planet survive and thrive, protecting our botanical heritage for future generations, one seed at a time” .


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