The Seed Unit at the Royal Botanic Gardens, Kew

Abstract

Botanic gardens have, for many years used the exchange of seed as one of the ways by which they increase the size of their collections. Annual seed lists have become a regular feature of a botanic garden's modus operandi, and often list large numbers of items collected during the previous year(s) from plants growing in the gardens. Until recently the Seed List distributed by the Royal Botanic Gardens, Kew contained 4000-5000 items, representing the annual haul from plants growing in the Gardens. At the end of each season surplus seed was set aside or thrown away, and new collections were made for the next seed list. Repeat collections made year after year, of the seed of many species, which may later be thrown away for lack of demand, is wasteful and time consuming. One way of reducing this waste is to store the seed under conditions which prolong its viability so that collections from one year can be retained for distribution in succeeding years until the stock is exhausted. The implications of doing this have already been discussed (Thompson, I97oa) in relation to the quality of the material in the Seed List. However, improved storage conditions are not a complete answer to the problem. The viability of seed held in store for many years must be checked periodically to ensure that seed that has died is not kept and later distributed. These viability measurements may be based on chemical or biological tests, and the tests require seed samples which are free from contamination with other parts of the plant, undeveloped seeds,-soil, etc. Thus the change from a system based on annually repeated collections to one based on single collections stored for long periods, not only demands provision of special storage conditions, but also of seed testing facilities, and improved methods of harvesting and cleaning. The scale and complexity of these additional facilities will vary with the particular needs of different establishments. The intention here is to describe the Seed Unit, which has been established at the Royal Botanic Gardens, Kew, for the storage, testing and distribution of seed.