Discovery of gene code for rice may help feed world

Scientists have deciphered the genetic blueprint of the rice plant - the world's most important staple crop - in what is seen by many as a vital step towards feeding the planet.

Proponents of the breakthrough say understanding the genetic code will enable scientists to develop new varieties that could boost yields to sustain the growing human population.

More than half of the people on earth rely on rice for 80 per cent of their dietary needs, but production must increase by a third in the next 20 years to feed the developing world.

A Japanese-led consortium of 32 institutions in 10 countries helped in the Rice Genome Sequencing Project. The completed map, published in the journal Nature, shows that the plant has 37,544 genes, about 7,500 more than the human genome, positioned along 12 chromosomes.

"Rice is a critically important crop, and this finished sequence represents a major milestone," said Robin Buell, a plant geneticist at the Institute for Genomic Research in Rockville, Maryland, one of the consortium.

"We know the scientific community can use these data to develop new varieties that deliver increased yields and grow in harsher conditions.

"The genetic map will greatly speed the hunt for genes that increase yield, protect against disease and pests, or provide drought-resistance in rice and other cereal crops."

Knowing the precise details will also give scientists an insight into other closely related cereal crops such as barley, corn, wheat, rye, sorghum and millet, said Joachim Messing of Rutgers, the state university of New Jersey.

"The rice genome is the Rosetta Stone of all the bigger grass genomes," Dr Messing said. "Knowing its sequence will provide instantaneous access to the same genes in the same relative physical position in other grasses and accelerate plant gene discovery in many important crops such as corn and wheat."

The importance of publishing the full rice genome was underlined in 2002 when 20 leading scientists publicly complained about the plans of multinational companies to keep the data they had on rice genes a commercial secret. But Monsanto and Syngenta have since donated their data to the consortium, which enabled the project to be completed on time and to budget.

Richard McCombie, of Cold Spring Harbor Laboratory in New York, a co-leader of the study, said: "This study revealed thousands of genetic markers or signposts in the rice genome that are of immediate use to plant breeders and others working to improve rice agriculture.

"This is also the first finished genome sequence we have from any crop plant, so rice is a great model to use genome sequence information to improve many aspects of agriculture."