AGRICULTURE REPORT - Scientists Complete a Genetic Map of Ri

AGRICULTURE REPORT - Scientists Complete a Genetic¹ Map of Rice
By Mario Ritter

Broadcast: Tuesday, August 16, 2005

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 genes² 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 productivity³. 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 mustard⁴ family. Its genome was completed in two thousand.

Genes produce proteins which guide the building of organisms. Genes are placed along chromosomes⁵. 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 supervised⁶ 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.  I'm Faith Lapidus.

1 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

2 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

3 productivity   

n.生产力，生产率，多产

参考例句：

• Farmers are introducing in novations which increase the productivity.农民们正引进提高生产力的新方法。
• The workers try to put up productivity.工人设法提高生产率。

4 mustard   

n.芥子，芥末，深黄色，强烈的兴趣，热情的人

参考例句：

• This meat should be seasoned with salt and mustard.这肉里应该加点盐和芥末调味。
• This mustard is hot enough to bite your tongue.这种芥末很辣，你的舌头会吃不消的。

5 chromosomes   

n.染色体( chromosome的名词复数 )

参考例句：

• Chromosomes also determine the sex of animals. 染色体也决定动物的性别。 来自《简明英汉词典》
• Each of four chromosomes divide longitudinally. 四种染色体的每一种都沿着纵向分裂。 来自《现代汉英综合大词典》

6 supervised   

v.监督，管理( supervise的过去式和过去分词 )

参考例句：

• The architect supervised the building of the house. 建筑工程师监督房子的施工。 来自《简明英汉词典》
• He supervised and trained more than 400 volunteers. 他指导和培训了400多名志愿者。 来自辞典例句