The Threat to Plant Genetic Resources

Plant genetic resources are increasingly threatened at the ecosystem, species, and genetic levels, largely as a result of human activities. For example, in the case of crop plants, the proportion of the wheat crop in Greece contributed by landraces or old, indigenous varieties declined from 80 percent in 1930 to less than 10 percent in 1970. In China, nearly 10,000 wheat varieties were in use in 1949, but only 1000 were still in use by the 1970s (FAO 1998). In Cambodia, unique rice varieties were lost in the 1970s when war disrupted agricultural production. Stored seed in the national gene bank was eaten or rotted, and numerous landraces would therefore have died out, were it not for the duplicates preserved in the International Rice Research Institute (IRRI) gene bank in the Philippines. In Mexico and Guatemala, urbanization has displaced some of the populations of teosinte (Zea mexicana), the closest relative of corn, and these populations have also suffered genetic pollution from genetically modified corn (Quist and Chapela 2001).

It is likely that virtually all plant species are currently suffering loss of genetic variation to varying degrees: it was estimated that 25 to 35 percent of plant genetic diversity could be lost over the next 20 years (Maxted, Ford-Lloyd, and Hawkes 1997).

National and international agencies must deal with a paradoxical confrontation between conservation and development. Plant breeders throughout the world are rightly engaged in developing better and higher-yielding cultivars of crop plants. This involves the replacement of genetically variable, lower-yielding landraces with products of modern agriculture, which are much more genetically uniform. Thus, genetic uniformity is replacing diversity. These same plant breeders are, however, dependent upon the availability of a pool of diverse genetic material for success in their work, and thus are unwittingly causing the genetic erosion of plant diversity that they themselves will need in the future—hence the paradox. Of course, replacement of traditional landraces by modern cultivars is not the only cause of genetic erosion or loss of genetic diversity; other changes in farming systems, the intensification of production systems, overexploitation, introduction of exotic cash crops, human socio-economic changes and upheaval (e.g., extinction of tribal cultures, urban sprawl, land clearances, food shortages), as well as both natural and man-made calamities (e.g., floods, landslides, or wars) have all acted against the retention of socio-economically important biodiversity.

TABLE 21.3 Estimated Annual Markets for Genetic Resources Products (ten Kate and Laird, 1999)


Lower Estimate

Estimate (US $


(US $ billion)





Botanical Medicine



Major Crop






Crop Protection






Cosmetics & Personal



Care Products




Plant genetic resources cost/benefit analysis

The economic benefit of plant genetic resources use has recently been reviewed by ten Kate and Laird (1999). Although it is very difficult to estimate precisely the annual global market value of plant genetic resources, they suggest a range of figures between US $500 to $800 billion; the breakdown of figures is given in Table 21.3. The use of wild species by local communities should not be underestimated; for example in Tanzania in 1988, it was estimated that the value of all wild plant resources to rural communities, whether through subsistence consumption or sale, was more than US $120 million (8 percent of agricultural GDP) (FAO 1998).

Of the industries that depend on diversity, agriculture remains by far the largest. Phillips and Meilleur (1998) estimate that endangered food crop relatives have a worth of about US $10 billion annually in wholesale farm values. Various studies, mostly conducted on cereals, have estimated that more than 50 percent of the increase in crop production has been due to the improvement of crop cultivars, and such improvement is brought about by transferring desirable genes/traits to crops from landraces and other more distant germplasm sources. Thus, the transfer of dwarfing genes from Japanese semi-dwarf material to U.S. and Mexican wheat stocks led to the revolution of wheat production in the world during the 1960s and 1970s (see Grains, pp. 45, 53). This so-called "green revolution" helped food-deficient countries like India become food sufficient, and ultimately even net exporters within a short period of 10 years.

The transfer of genes for high sugar content to the tomato (Lycopersicon esculentum) from its wild relative (L. chmielewskii) has generated an additional income of US $5 to $8 million per year for the tomato industry (Iltis 1988). Although precise estimates of the global value associated with the use of plant genetic resources do vary, it is clear that plant genetic resources have a real and substantial value.

However, there is a cost involved in conserving this diversity. Using the FAO (1998) figure of 6.1 million accessions in world gene banks, and using the estimates of Smith and Linington (1997) for the cost of obtaining the material (US $597 each) and incorporation of the material into the gene bank (US $273 each), we then have a total cost of US $5.3 billion for collecting and conserving the world's germplasm in gene banks. Even the cost of maintaining existing ex situ gene bank accessions is not insignificant considering the commitment to conserve is open-ended. Taking Smith and Linington's (1997) estimates of the annual cost of maintaining an accession of US $5 each, then for 6.1 million accessions the running cost is US $30.5 million per year. We have no estimate of in situ expenditure, but for the United States at least, it has been estimated that more than 98 percent of all conservation expenditure is spent on in situ activities related to wild species (Cohen et al. 1991). Although these figures are relatively high, they are small compared to the annual market for genetic resources use. Therefore simple cost/benefit analysis clearly indicates humans are very short-sighted to carelessly oversee loss and threat to plant genetic diversity.

International treaties and plant genetic resources

Recognition of the fundamental importance of these issues was highlighted at the United Nations Conference on Environment and Development (UNCED) held in Rio de Janeiro, Brazil in 1992, and has been enshrined in the resulting Convention on Biological Diversity (CBD). Its objectives are:

... the conservation of biological diversity, the sustainable use of its components and the fair and equitable sharing of the benefits arising out of the utilization of genetic resources, including by appropriate access to genetic resources and by appropriate transfer of relevant technologies, taking into account all rights over those resources and to technologies, and by appropriate funding (

The CBD was the first global treaty that linked the conservation of biodiversity to sustainable utilization. It represents a milestone in biodiversity conservation thinking, reflecting international acknowledgement of the loss of our biological resources, their role in human development and wealth creation, and the urgent need for conservation action and sustainable exploitation. The CBD is now recognized as the primary guiding framework for the conservation, management, and use of biodiversity.

More specific reference to plant genetic resources is made in the International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGRFA), agreed by 116 countries in Rome in November, 2001. The International Treaty is in harmony with the CBD, and many of its articles make explicit propositions in the CBD, especially as regard Farmers' Rights—recognizing the contribution that the local and indigenous communities and farmers of all regions of the world have made to the conservation and development of plant genetic resources. Farmers' rights are equated with plant breeders' rights. It is a legally binding international agreement, which will come into force when ratified by at least 40 states. The objective of the ITPGRFA was expressed in Article 1.

The objectives of this Treaty are the conservation and sustainable use of plant genetic resources for food and agriculture and the fair and equitable sharing of the benefits arising out of their use, in harmony with the Convention on Biological Diversity, for sustainable agriculture and food security (

It takes into consideration the particular needs of farmers and plant breeders, and aims to guarantee the future availability of the diversity of plant genetic resources for food and agriculture on which they depend, and the fair and equitable sharing of the benefits.

These Treaties both provide a broad framework for plant conservation linked to sustainable and equitable use of resources, but they lack any specific strategy for achieving their objectives. The CBD's Conference of the Parties, who are charged with implementing the CBD, adopted a Global Strategy for Plant Conservation (GSPC) at its seventh meeting in November, 2001. GSPC provides the necessary specific conservation targets that are to be achieved by 2010, several of which relate to plant genetic resources (the full list of targets is provided in Conservation of Wild Plants, p. 402):

• Thirty percent of production lands to be managed consistent with the conservation of plant diversity

• Seventy percent of the genetic diversity of crops and other major plant genetic resources to be conserved

• No species of wild flora is to be subject to unsustainable exploitation resulting from international trade

• Thirty percent of plant-based products to be derived from sources that are sustainably managed

• A reversal of the decline of plant resources that support sustainable livelihoods, local food security and health care

• Every child to be aware of the importance of, and the need to conserve, plant diversity

• The number of trained people working with adequate facilities in plant conservation and related activities to be doubled

• Networks for plant conservation activities established or strengthened at international, regional, and national levels

Even more detailed targets are being used by many national governments and regions—for example, the European Plant Conservation Strategy.

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