We live in critical times for the world's diversity of plants and animals. It is universally agreed that a catastrophic loss of biological diversity is occurring at the moment, with species, and equally importantly, genes being lost forever. However, the signing of the Biodiversity Convention at the Earth Summit in 1992 drew attention to the need to conserve and equitably utilize biological diversity for the benefit of all humankind. The convention placed emphasis on the need for a complementary approach to conversation that employed both ex situ and in situ techniques. This book therefore provides a practical and theoretical introduction to the techniques of in situ conservation of plant genetic resources. It includes methodologies, case studies and in-depth discussion of on-farm and genetic reserve conservation, written by acknowledged international experts on the subject.