Seed banks work as storage facilities for seeds from various plant species, preserving genetic diversity and safeguarding plant resources for future generations. Here’s how they work:
1. Seed Collection and Selection
Best seed banks collect seeds from different plant species, focusing on varieties with unique characteristics or at risk of extinction. They may collect seeds from wild plants, cultivated crops, or rare varieties. Collection can occur in the field, where trained personnel harvest seeds from mature plants or obtain seeds from other seed banks or institutions.
2. Seed Cleaning and Drying
Collected seeds are carefully cleaned to remove any impurities like dirt, plant debris, or insect parts. This ensures they are viable and not susceptible to disease. Drying is a critical step because seeds need to have low moisture content to remain viable in storage. Moisture is removed by placing seeds in a controlled drying environment, which typically involves cool and low-humidity settings.
3. Seed Testing and Quality Control
Before storage, seeds undergo germination tests to check their viability. If a certain percentage of seeds germinate successfully, they are deemed viable for storage. Seeds are also inspected for signs of diseases or pests, as infected seeds could compromise the collection.
4. Storage in Controlled Environments
Dried seeds are placed in sealed containers, often glass or aluminium pouches, to prevent moisture from getting in. The storage facilities maintain a cold and stable temperature, typically around -20°C (-4°F), which helps slow down the seed’s metabolic rate and prevents premature germination or degradation. Some seeds, called "recalcitrant seeds" (like those of tropical plants), do not tolerate drying and freezing well, so they are stored in different conditions, such as moist environments at slightly above-freezing temperatures.
5. Periodic Monitoring and Regeneration
Stored seeds are periodically tested for viability to ensure they’re still capable of germinating. If their viability drops below a certain threshold, new seeds are collected or existing seeds are germinated and harvested to replace the old stock. This process, known as "regeneration," ensures the bank always has a viable supply of seeds, even for species that may have become extinct in the wild.
6. Access and Utilization
Seed banks aren’t just storage vaults; they are resources for scientists, breeders, and farmers. Seed banks share seeds with researchers who are working on plant breeding, disease resistance, or climate adaptability. They are also accessed in emergencies when crops are lost due to disasters.
Seed banks play a vital role in biodiversity conservation, food security, and ecological resilience. They help safeguard plant genetic diversity, allowing for adaptation to changing climates and emerging agricultural challenges. Examples like the Svalbard Global Seed Vault and national seed banks worldwide underscore the importance of these facilities for global conservation efforts.