Although it is preferable to preserve plant species in their natural biotope, a seed bank can be a last lifebuoy for protecting endangered plants from extinction. Seeds are small: in a space of a few cubic metres, thousands of species can be stored at the same time. Moreover, they can keep their germinating power for dozens, even hundreds of years if they are properly dried before being frozen. The long-term seed banks of the Botanic Garden contain, in particular, rare and endangered flowering plants from Belgium, endangered plant species from the copper flora of Katanga (Democratic Republic of Congo) and wild beans.
Of course, we also preserve seeds from the Botanic Garden’s extensive collection of living plants. The storage period is shorter, with the aim of propagating species. The seeds also function as a back-up for our plant collection and are exchanged with other botanic gardens and scientific institutions all over the world. Every year, we deliver our seed list to a network of 600 correspondents.
> List of Seeds (Index seminum)
Seeds from our endangered wild plants
Part of our collection contains seeds from rare wild plants from Belgium. They are preserved at a temperature of -20 °C, which allows them to keep their germinating power for a very long time (100 years). Germination experiments are regularly carried out to check this. This ex-situ conservation fits into a global strategy to preserve plant species, and, where possible, to reintroduce them into their natural environment.
Seeds from the copper flora of Katanga
The Copperbelt of Katanga in the Democratic Republic of Congo consists of hills with extremely high concentrations of copper in the soil. Usually, that metal is toxic for plants, but some 600 species, which have adapted to the copper-rich soil, thrive there. 30 of these species are not found anywhere else. This flora is being threatened, however, by mining activities.
The Seed Bank of the Botanic Garden is responsible for the long-term storage of collected seeds – a valuable undertaking in itself, and an important part of a broader conservation strategy. After the mining activities have finished, the seeds will be sowed again to stabilize the soil and to protect against erosion.
Wild bean seeds
Our Seed Bank also contains an important collection of wild beans and bean type plants (Fabaceae). The genera Phaseolus and Vigna are particularly well represented. They include protein-producing plants that play an important nutritional role – for example, the common bean (Phaseolus vulgaris), the runner bean (Phaseolus coccineus), the black-eyed pea (Vigna unguiculata), and the mung bean (Vigna radiata).
The aim of the collection is the long-term preservation of the genetic variability of this group – essential to secure the future of these important food crops. These seeds are also stored at -20 °C. A collection such as this one is an important source of genetic material for scientific research and breeding.
> Database Phaseolinae