The conservation and maintenance of representative collections covering the genetic variation of cultivated plants and their wild relatives is still inadequate. The paucity of such collections and the inadequacy of fundamental research in this area hinder the development of practical work on the utilization of the world's genetic resources. In addition, insufficient knowledge and commercial interests interfere seriously with an international exchange of information and resources.
Plant genetic resources are essential for future food supplies. They are, however, declining at an alarming rate and the threat to plant species has never been greater. The chief cause of the decline is the replacement of local crop varieties, which is a direct result of £green revolution' technology.
Of the 250,000 flowering plant species currently estimated to exist, tens of thousands remain undiscovered and only some 5,000 have been tested for their pharmaceutical attributes. Some 25,000 of these species are currently under threat. The tropical, non-industrialized world contains almost all the areas rich in wild crop genetic resources. These areas are also those of high political and economic instability and in greatest need for development.
Genetic resources conservation is directly related to the fundamental problem of the future of human welfare in terms of food supply and of other plant products. The conservation of plant resources on which the future improvement of the world's staple crops must depend has more than scientific interest; it is a safeguard to meet the inevitable requirements of population pressure. Crop improvement, which has contributed so much to plant productivity and total world production, requires, and will continue to require ever more urgently, the genetic resources on which the increasingly sophisticated methods of plant breeding will depend. The extinction of wild species and varieties - probably at a rate of one a day - may pose a grave threat to world food supplies. Conservation of plant genetic resources has to be carried out both ['ex-situ'] through an appropriate system of gene banks and ['in-situ'] through a world wide network of protected areas including biosphere reserves and biogenetic reserves.