The Millennium Seed Bank Project
Volume 2 Number 9 - December 1997
Seed banks have been used for the conservation of crop germplasm for several decades and international standards have recently been affirmed, by FAO and the International Plant Genetic Resources Institute, for their operation.
The Kew Seed Bank
The Kew Seed Bank has shadowed this work since the late 1960s and adapted the techniques for the conservation of 'wild' species. Initially, the Bank's work was to more efficiently meet the needs of the annual Index Seminum seed exchange by collecting seed from the gardens and storing it for distribution over several years. Improved technology based on research, redirection of effort towards conservation of seed collected directly from the wild, and greater emphasis on conditional distribution for research rather than display, has followed.
Concentrating on seed of native plants of the United Kingdom (U.K.) and those from within the world's drylands, the Kew Seed Bank has demonstrated the wide applicability of seed banking for the ex situ conservation of wild plant populations over decades and the potential for storage over centuries. Perhaps seed banking's greatest significance within the array of botanic garden conservation techniques is the amount of intra-specific variation that can be conserved.
About three years ago, the Kew Seed Bank held seed collections representing less than 2% of the world's flowering plants. Against a background of increasing threat to the world's floras, a decision was taken to scale up the work and, in 1995, RBG Kew submitted the 'Millennium Seed Bank (MSB) Project' for funding to the Millennium Commission, one of the distributors of the U.K.'s national lottery funds.
The Commission, which funds U.K. based projects marking the Millennium, granted up to £30 million towards this Project.
Aims of the Millennium Seed Bank Project
The Project aims to
(a) collect and conserve seed of 10% of the world's flowering plants, mainly from within the drylands, through international effort, by the year 2010,
(b) collect and conserve seed from most U.K. species producing 'bankable' seed by the year 2000,
(c) make many of the seed available for research through benefit-sharing agreements according to the terms of the Convention on Biological Diversity (CBD),
(d) carry out the research necessary to maximise seed longevities and to improve the efficiency of seed banking and assemble a seed information database,
(e) transfer the technology to partners in collaborating countries by providing research opportunities and training and
(f) provide a building, by the year 2000, located next to the Kew Seed Bank at Wakehurst Place in Sussex, as the focus for the above work and in which seed banking techniques and wider plant conservation issues can be interpreted for the public.
About 70% of the total Project funding of £80 million (about $128 million) is now in place with the Millennium Commission's grant boosted by substantial contributions from the Wellcome Trust and Orange plc.
The MSB Project aims to build on previous collaboration with institutes within the drylands in African and Latin American countries. However, RBG Kew will be pleased to hear from botanic gardens, especially the relatively few that are located in arid or semi-arid areas and where the mean temperature of the coolest month does not fall below zero, that might be interested in collaborating with the Project. It is also keen to hear from any botanic garden that might wish to back-up their own seed conservation work by depositing wild collected and high quality, duplicate samples within the MSB. Please contact email@example.com to discuss the possibilities.
Setting Up Your Own Seed Bank
Not all seed banking needs to be on such a scale. In essence, seed banking involves
(a) random and even sampling of mature seed,
(b) checking that the seeds of the species can be dried without killing them, either by reference to the literature, experimentation or even a considered guess based on small seed size, fruit type or habitat,
(c) cleaning and drying as soon after harvesting as possible, (d) careful packaging and placing at a low temperature and
(e) the monitoring of viability.
At a low technological level, seeds can be effectively dried using desiccants such as silica gel or even other dry seeds. Once properly dried and sealed inside a foil bag, seeds will often live years or decades even at room temperatures, though lower temperatures give significantly longer storage and are obviously preferred if affordable.
It is stages (b) and (e) which lend certainty to the operation but which present the most difficulty for botanic gardens with limited resources. It is hoped that the MSB Project will eventually not only try to help close the gap in our knowledge of species' seed storage behaviour but also improve dormancy-breaking treatments necessary for monitoring seed viability. This aside, it could be argued that even in the absence of stages (b) and (e), it is better to conserve seed collections, albeit at a lower standard, that safeguard some but not all of the species, than do nothing and limit the value of material collected by botanic gardens.
It is surely important that more botanic gardens add seed banking to their armoury of techniques for fighting against plant genetic erosion and extinction. However, in order to have any hope of winning this fight, the botanic gardens community will need to co-ordinate effort, gradually improve standards up to those used in crop germplasm conservation, examine the possibilities for collaboration on storage and research, and capitalise on the political climate afforded by the CBD. In this way, botanic gardens may play an even more crucial role in the final line of defence against plant extinction.