Scientists Complete a Genetic Map of Rice magazine, percent, completed, represents, English

李武军

I'm Faith Lapidus with the VOA Special English Agriculture Report.
Scientists now know a lot more about a grain that people have eaten for ten thousand years. Research teams around the world have completed a map of the genes of rice. Such a map is called a genome. The findings appeared last week in the magazine Nature.
The map represents ninety-five percent of the rice genome. And the information is considered ninety-nine point nine-nine percent correct.
The aim is to speed up the improvement of rice. The scientists warn that the kinds of rice plants used now have reached the limit of their productivity. Yet world rice production must grow by an estimated thirty percent in the next twenty years to meet demand.
In their paper, the researchers say rice is an excellent choice for genetic mapping and engineering. Rice genes have only about three hundred ninety million chemical bases. That might sound like a lot. But other major food grains have thousands of millions.
The new map could better explain not just rice. Rice shares a common ancestor with other crops in the grass family. These include corn and wheat.
Also, rice shares more than seventy percent of its genes with Arabidopsis. This plant is in the mustard family. Its genome was completed in two thousand.
Genes produce proteins which guide the building of organisms. Genes are placed along chromosomes. Rice has twelve chromosomes. The scientists found almost thirty-eight thousand genes. By comparison, studies have found only about twenty-five thousand genes in humans.
The International Rice Genome Sequencing Project in Tsukuba, Japan, led the research. The effort started in nineteen ninety-eight.
The Rice Genome Research Program in Japan supervised the mapping of about half of the genome. American researchers were responsible for three chromosomes. Chinese and Taiwanese researchers mapped one each. A French group mapped one and part of another. Researchers in Brazil, Britain France, India, South Korea and Thailand also took part.
The project was expected to take ten years. But the work was finished in six because many of the groups shared information and technology. Two companies, Monsanto of the United States and Syngenta of Switzerland, also shared their research.
This VOA Special English Agriculture Report was written by Mario Ritter. Our reports are online at WWW.51VOA.COM. I'm Faith Lapidus.