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Scientists Complete Genetic Blueprint of Rice

Scientists have finished mapping the genetic blueprint of rice, work that could lead to a significant increase in the output of rice and other grains to meet a growing global population.

Experts say more than half of the world's population eats rice as part of the daily diet. They project that over the next two decades, the demand for rice will grow by 30 percent as the global population increases. But with present conditions, there won't be enough rice to go around.

So plant geneticists have been working to identify the molecular building blocks of rice that could potentially increase yields by making the grain resistant to pests, diseases and harsh weather conditions.

In a study published in the August 11 issue of the journal Nature, researchers from 10 countries, led by Japan's International Rice Genome Sequencing Project, report pinpointing the locations of more than 37,500 rice genes along the plant's 12 thread-like chromosomes.

The genetic material is tightly packed inside the nucleus of each cell and is responsible for a wide variety of plant traits.

Researcher Robin Buell of the Institute for Genomic Research in Rockville, Maryland, says different strains of rice have different characteristics that make them vulnerable to various growing conditions.

For example, she says some strains are more tolerant of stressful conditions but yield less than strains that are susceptible to diseases or unfavorable soil conditions.

"So, what you want to do is something that is well known in the breeding community called hyper-vigor where you bring the best traits from two very different parents and bring them together and try to make the optimal variety," she said. "So, having the genome sequence will accelerate peoples' efforts to identify the genes that are important for these traits and bring them together in a genetic background that's most well-adapted to the environmental conditions."

Researchers began sequencing the rice genome in 1998.

Now that it's complete, study co-author of Richard McCombie of Cold Spring Harbor Laboratory in New York says the public will be able to gain free access to all or parts of the genetic information.

"Having the whole thing also makes it possible that people can look at just small parts of it that are of interest to them," he said. "So for instance if scientists and breeders in a given country have mapped a trait that is very important to the agriculture in their country, they can look in that region now of the genome and look at that small part of the sequence and see the genes that are there."

Researchers say the finished rice sequence shows that it shares many of the same genes with other cereal grains, including corn, wheat, and barley, holding out the potential for improvement of those crops as well.