Banking seeds for the future

Verloren Valei recently received its first visit from South African members of the Millennium Seed Bank Partnership.

On the 8 March 2023, a team from the South African National Biodiversity Institute’s Millennium Seed Bank Partnership Project visited Verloren Valei, their first trip to gather seeds from the reserve. These seeds are collected in line with a target list of seeds which will ultimately be stored in the Millennium Seed Bank in the United Kingdom and the brand new seed bank at Kirstenbosch National Botanic Garden in Cape Town.

As its name suggests, the Millennium Seed Bank (MSB) was formed in 2000 by the renowned Kew Royal Botanical Gardens. The actual Millennium Seed Bank is located at Wakehurst Place in Sussex, and its aim is to provide a store of non-crop (i.e. wild) plant species from around the world. The seeds are storied in underground vaults at -20°C, and are regularly monitored to ensure they are still viable.

Millennium Seed Bank at Wakehurst Place in the United Kingdom
One of the six -20°C cold rooms in the underground vault

The Global Seed Vault which stores seeds from crop species is located at Svalbard in Norway.

The aim of the MSB is to provide “insurance” for wild plant populations, support in situ conservation and support community projects aimed at creating sustainable livelihoods. The MSB is also a resource for research scientists.

Jo Osborne, Southern African Programme Officer at the Millennium Seed Bank, says that seed banking is highly effective because most seed-bearing plants produce many seeds a year. Following the MSB’s strict protocols, the harvesting of a small percentage of them does not affect the existing population. Most seeds are desiccation-tolerant, which means they can be dried and then frozen.

“Seed collection allows us to obtain high genetic diversity in a small volume of material from relatively few samples,” she says. “The dried and frozen seeds can survive for very long periods of time, and it’s a relatively low-tech process. Seed banks are really Plan B, Plan A being to conserve the native populations in the wild.”

Ms Osborne is quick to point out that seed banks have their limitations too—many species are difficult to germinate and propagate, and the banks are also unsuitable for species that do not respond well to desiccation. Some species , such as those in the families Ericaceae and Orchidaceae, are short-lived in seed banks. These and similar species need other solutions to be conserved, such as cryogenic storage at -180°C, or via living collections at alternative, protected sites such as in a botanical garden.

Verloren Valei is famous for its orchids, and many of them are reliant on the presence of soil bacteria, or mycorrhiza, with which they live in symbiosis. This means that germinating the seeds successfully is extremely difficult. It’s challenges like these that the research conducted using the seed bank’s samples aims to overcome.

It’s a process

As noted, the Millennium Seed Bank Partnership follows clear protocols to ensure that the collection does not damage the in situ population. Thereafter, the seeds are sent to Kirstenbosch, where they are processed to remove impurities, and then onwards to the Millennium Seed Bank. There they are processed to ensure quality, before being stored in one of the underground vaults. The seeds are monitored for viability every decade, and a seed list is made available to researchers who can make requests to be given seeds for specific projects.

South Africa, with its rich plant biodiversity, is a major contributor to the seed bank, and has already had cause to be thankful for the collaboration. The first withdrawal from the seed bank was to recover Marasmodes undulata, which had become extinct in the wild, The last wild remnants of this yellow shrub were restricted to one site—the Orleans Camp Site in Paarl—until it was wiped out by a bush fire.

“The partnership with South Africa is a really great collaboration,” says Ms Osborne.

In the field

The seed-collecting expedition to Verloren Valei was led by Ntsakisi Masia, a conservation technician at SANBI, based at the Thohoyandou National Botanical Garden. Thohoyandou National Botanical Garden is responsible for seed collecting in Limpopo and Mpumalanga. She her colleagues were on the lookout for Moraea pubiflora, Moraea spathulata, Wahlenbergia lycopodioides, Hypoxis costata, Schizochilus cecilii subsp. culveri, Delosperma sutherlandii, Eulophia parvilabris, Monsonia transvaalensis, Streptocarpus dunnii, Drosera collinsiae, Geranium multisectum, Moraea elliotii, Holothrix scopularia and Delosperma deilanthoides.

“The reserve is breathtakingly rich in flora,” says Ms Masia. “We managed to collect several of our targets, and will be returning soon to collect more seeds from those were still in flower.”

Ntsakisi Masia and Itumeleng Machete collecting specimens of Helichrysum albilanatum herbarium in the field
Fergy Nkadimeng collecting seeds of Asparagus laricinus at Verloren Valei

The project to develop South Africa’s national seed collection is funded by the Arcadia Threatened Biodiversity Hotspots Programme and the Garfield Weston Foundation’s Global Tree Seed Bank Programme. The South African team collaborated with the Instituto de Investigação Agrária de Moçambique to provide training for its seed-collecting programme.

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