Wednesday, Aug 24, 2005
GM rice — top of the crops
Johnjoe McFadden— © Guardian Newspapers Limited 2004
WHILE WE in the West are preoccupied with cloning sheep, pigs, dogs and, of course, ourselves, scientists in the developing world are focussed on an organism of far greater importance: rice.
According to a Chinese saying, "the most precious things are not jade and pearls but the five grains." Earlier this month the genome of one of those five grains was laid bare when the complete genome sequence of rice was published in the journal Nature.
Rice is the staple food crop for three billion people, mostly in Asia. But most of those dependent on the crop still go hungry. About 800 million people do not have enough to eat, many of them children, and about five million will die of diseases related to malnutrition. And with the world's population increasing at a rate of about 86 million people a year, things could get a lot worse. It is estimated that rice production will have to increase by about 30 per cent in the next 20 years to keep pace with population growth and economic development. Where is all the food going to come from?
There are two principal ways to boost food production: increasing the amount of land under cultivation or increasing yields. Until the 1960s the favoured strategy was putting more land under the plough, resulting in the loss of much of the world's wilderness and native forest.
But in the 1960s scientists such as Norman Borlaug pioneered a new strategy, increasing crop yields through a mixture of seed improvement and technological inputs: the green revolution. As crops of the new varieties were planted, first in Mexico and then throughout the world, particularly in Asia, harvests soared and have continued to rise at a rate of about 2 per cent a year.
But the green revolution is grinding to a halt. There have been only small yield increases in recent years, and it is thought that rice grown on the most productive irrigated land has now achieved maximum production levels. The challenge for the future is to increase yields in more marginal lands, where much of the crop ends up in the bellies of insects or is devastated by drought or disease.
Many scientists (including Mr. Borlaug) believe that the only way to provide food security for the world's poorest people is to genetically engineer crops that are more resistant to nature's ravages.
The potential value of GM crops was highlighted earlier this year with the publication of the results of a Chinese study that demonstrated a 10 per cent increase in yield for farms that planted an insect-resistant GM variety of rice.
In a typically Chinese understatement, Jikun Huang, the director of the Centre for Chinese Agricultural Policy at the Chinese Academy of Sciences, said: "The performance of insect-resistant GM rice in trials has been impressive." Not only were yields up, but the use of pesticides dropped by 80 per cent and farmers reported a dramatic reduction in pesticide-related health problems.
But inserting a single gene is just tinkering. What the rice genome project provides is a blueprint of the entire genome and the capability to engineer the crop to meet the needs of farmers throughout the world.
The rice genome was sequenced by the International Rice Genome Sequencing Project, a unique collaboration of researchers in Japan, China, Taiwan, Thailand, Korea, the U.S., Canada, France, India, Brazil, the Philippines and the U.K. The project, with its insistence on making its data immediately available to scientists anywhere in the world at no cost, is a glowing example of one of the positive benefits of globalisation.
Of course, many aid organisations — often heavily influenced by Western green campaigns — have attacked the emphasis on GM technology, calling it a "technical fix" that does little to address the real social and economic causes of world poverty and hunger. They said the same several decades ago when widespread famine was predicted to follow a population explosion. The population explosion materialised but the famine did not. The reason was that while others argued for social reform, pioneering plant breeders launched the green revolution and saved millions from starvation.
Some 1.2 million people live on less than one dollar a day, and that dollar usually buys rice. But the crop is prone to many diseases, pests, and unpredictable climate change. Genetic engineering of crops to generate new varieties resistant to disease, pests, drought and salinity could revolutionise third-world farming. The release of the rice genome sequence places a powerful toolkit in the hands of researchers eager to improve crop yields.
(Johnjoe McFadden is professor of molecular genetics at the University of Surrey, England, and author of Quantum Evolution.)
Copyright © 2005, The Hindu.