Biodiversity, or genetic variation, is essential to the health of our planet and the wealth of our societies. Whether we regard it as a moral issue or as an economic one, its importance is paramount.

Throughout the history of evolution, species have died out at a steady rate, but this loss of biodiversity has always been balanced out by genetic mutation and natural selection. But in the modern world, we have reached a situation in which the rate at which species are dying out is far outstripping the rate of evolutionary increase.

The advent of biotechnology offers solutions to several present and future problems concerning biodiversity. Permitting the transfer of genes between different species of plants, animals and micro-organisms for example, hugely increases the genetic resources available to plant breeders. Associated techniques of recombinant DNA technology also allow conservationists to characterise existing genetic resources far more quickly and accurately. Since the beginning of agriculture, farmers have taken advantage of genetic resources that until recently have been freely available throughout the world.

High dependence on few plants

The prosperity of nations has initially been built on the successful development of agriculture that has in turn been dependent on the use of suitable genetic raw materials.

Today, out of an estimated quarter of a million species of flowering plants, around 500 are used as human food and only three species (rice, wheat and maize) supply almost 60% of the nutrients that humans derive from plants. Such high dependence on so few plant species is exacerbated because the genetic variation within each of these species has been eroded through selection programmes of plant breeders. There is a danger that these crops will not have retained sufficient genetic variablity to enable them to adapt to environmental changes.

In order to produce improved plants that, for example, are resistant to pests and diseases, or more tolerant to salinity and drought, or have lower requirements for soil nutrients, plant breeders traditionally rely on accessing genetic material from as wide a range of wild species and traditional varieties as possible. Biotechnology may offer alternative solutions to some of these problems, but efforts to conserve genetic diversity are essential and need to ensure both security and availability of resources and provide adequate informaiton about it to anyone who wants it. All conservation methodes available, in-situ, on-farm and in gene banks, must be put to work. In addition, traditional knowledge about local varieties and wild plants and their uses should be tapped.

FOOD TODAY 06/1998