The current world population of 5.6 billion is expected to double to 11 billion by 2050. Ninety-seven percent of that increase will occur in developing countries, where 90% of the population will be living 50 years from now. Asia will be, by far, the most populous continent. Food demands will more than double by the year 2025 and could triple by 2050.2 By the year 2025, the grain requirements of the developing countries will be more than three times that of the entire USA harvest. The enormity of the food security issue is best illustrated by the fact that in the next fifty years the global population will consume twice as much food as has been consumed since agriculture began 10,000 years ago.3,4 The challenge for the agricultural sector is to double food production by 2025, and triple it by 2050, on less land, with less water, and under increasingly challenging conditions.5 Food security and biodiversity will continue to be our most pressing challenges.
For the developed nations, population increases can be accommodated in part by eating lower on the food chain and consuming grains directly, but the developing world is already doing that. Because new arable land in the developing world is becoming steadily more scarce, higher yields can come with better agronomy dependent on a combination of more fertilizer, plowing, water lifting energy and improved plant material. All but the last are agricultural inputs that compete for meager resources available in developing countries. Therefore, breeding for better crop plants will be the central focal point around which all strategies to increase crop yields will develop.
Watanabe and Pehu6 in a recent book titled, "Plant Biotechnology and Plant Genetic Resources for Sustainability and Productivity", outline several case studies on different crops/ commodities that look closely at the introduction of a particular crop or commodity. They also cover topics on the contribution of plant introduction to the global economy. Nevertheless, it is relevant to take a look at the contribution and other values of PGRFA to modern varieties, including its role in integrated pest management (IPM).
The improvements in agricultural production brought about through the use of modern varieties have been possible because of the rich and varied genetic diversity in farmers' landraces, and of wild and weedy species. There are now several examples of the introgression of valuable agronomic traits from landraces, and wild relatives of crops.1 The green revolution of the 1960s is a good example that permitted spectacular increases in yields of rice and wheat, without which it is unlikely that the food needs of rapidly expanding populations would have been met. In wheat, rice and maize, about half of the increase in production has been ascribed to breeding new varieties through the use of plant genetic resources. The remaining increase was derived from the use of fertilizers, pesticides and improved crop management. Over the past 25 years, irrigated rice production has increased at 3% per year. Nearly 60% of that growth is the result of increases from breeding. Other successful products of this era through plant breeding are hybrid corn and changes in the photope-riod response of soybeans, making it the most important legume and oil crop in the world.7,8
There is no doubt that plant genetic resources are very valuable. Estimates of the global value associated with the use of these resources vary from hundreds of millions to tens of billions of dollars per year. For example, the contribution of rice landraces from South Asia, assembled in the region's genebanks, is estimated to be about $150-200 million per year.9 Similarly, estimates for the core wheat collection, maintained at the International Maize and Wheat Improvement Center (CIMMYT) in Mexico, to agriculture in the OECD countries range from $300 million to $11 billion per year.10 These ranges indicate the difficulty in assessing their value. Most estimates do not usually give the value of the genetic material per se, but rather aggregate value of both the genetic material and the work of plant breeders and other research inputs.
Host plant resistance to pests and diseases is the first line of defense, and is an essential component of integrated pest management (IPM) programs worldwide. Several successful IPM programs depend on the development of plant varieties resistant to both biotic and abiotic stresses. Plant genetic resources (wild, primitive and cultivated gene pools) provide the essential genes needed to develop resistant crop plants. Successful programs in rice, potatoes, beans, wheat, maize, vegetables, fruits and other crops have been developed using conventional breeding strategies. However, as a result of the last twelve years' using tools of genetic engineering, it is now possible to add specific genes (transgenes) to many crop plants, most microorganisms, and some insects.
During the period from 1986 to 1997, approximately 25,000 field trials of transgenic crops were conducted globally on more than 60 crops with 10 traits in 45 countries. The most frequent crops featured in transgenic crop field trials were maize, tomato, soybean, canola, potato and cotton, and the most frequent traits tested were herbicide tolerance, insect resistance, product quality and virus resistance.11,12
Plant genetic resources continue to play a major role in genetic improvement of crops. Strong international collaboration is already underway in:
1. The characterization of important genes and gene products;
2. The relationship between gene structure and function;
3. Regulatory mechanisms of gene expression;
4. Alteration and use of germplasm resources; and
5. The cellular and molecular mechanisms underlying human nutrient requirements.2 Research in these areas is essential to meet the needs of sustainable food and agriculture development.
Was this article helpful?