The case for conserving biodiversity is well-established on economic as well as scientific grounds. Biodiversity is essential for sustainable development, adaptation to a changing environment and the continued functioning of the biosphere - indeed, to human survival itself. Plant breeders are dependent upon the availability of a large pool of diverse genetic material represented by local races and wild relatives, since in themselves modern crop varieties provide too restricted a genepool for further breeding. Without the ability to draw from a diverse genetic reservoir, further improvement may not be possible. It is therefore essential that guidance is available on collecting plant germplasm. This reference work aims to provide the prospective collector of plant germplasm with generic as well as specific, and theoretical as well as practical, information. The International Plant Genetic Resources Institute (IPGRI), together with FAO, IUCN and UNEP, co-operated to produce this book. The volume is a reference work and is aimed at both new and experienced collectors as well as those with a general interest in plant genetics, breeding and biodiversity.