AGRICULTURE REPORT - Hybrids

AGRICULTURE REPORT - Hybrids²
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Broadcast: Tuesday, June 08, 2004

This is Steve Ember with the VOA Special English Agriculture Report.

Since ancient times, farmers have chosen the seeds for the coming year from the biggest and best plants in their crop. The hope is that these seeds will have the same good qualities as their parent plants. This method is called inbreeding. But experts say it is not the best way to develop seed with strong, healthy qualities over time.

In nineteen-oh-six, the genetic³ researcher G.H. Shull started work on breeding corn in New York State. He found that if he mated two inbred groups of corn plants, he could create a stronger new line of corn. This process is called crossbreeding. It produces hybrids from putting together different kinds of related plants.

Researchers soon recognized that they could crossbreed four inbred lines of corn. The result is stronger than corn crossbred only once. Hybrid¹ corn first appeared in nineteen-twenty-one. Today, almost all corn planted in the United States is hybrid. And farmers harvest about seven times more corn from each hectare than they did seventy years ago.

Corn is not the only hybrid crop. Yuan Longping is called the Father of Hybrid Rice. He and other Chinese scientists worked on this idea in the nineteen-sixties and seventies. The first hybrid rice appeared in nineteen-seventy-four. Mister Yuan used three lines of parent seed that produced fifteen to twenty percent more grain. By nineteen-ninety-five, half of all the rice grown in China was hybrid.

There are also hybrid animals. Long ago, farmers discovered that a female horse mated with a male donkey produces a mule⁴. This animal is strong and good for work, although it cannot reproduce.

In the early nineteen-eighties, American fish farmers wanted to raise striped bass⁵. This fish had almost disappeared from the wild. So researchers created a fast-growing hybrid bass. By two-thousand, fish farmers harvested almost seven-million kilograms of the new sunshine bass.

Hybrids are not the answer to every problem in agriculture. New hybrid seeds must be bought each year. They also cost more than other seed. Hybrids can take many years to develop. And not all crops can be crossbred successfully. But hybrids have been an important development for productivity.

This VOA Special English Agriculture Report was written by Mario Ritter. This is Steve Ember.

1 hybrid   

n.(动，植）杂种，混合物

参考例句：

• That is a hybrid perpetual rose.那是一株杂交的四季开花的蔷薇。
• The hybrid was tall,handsome,and intelligent.那混血儿高大、英俊、又聪明。

2 hybrids   

n.杂交生成的生物体( hybrid的名词复数 )；杂交植物（或动物）；杂种；（不同事物的）混合物

参考例句：

• All these brightly coloured hybrids are so lovely in the garden. 花园里所有这些色彩鲜艳的杂交花真美丽。 来自辞典例句
• The notion that interspecific hybrids are rare is ill-founded. 有一种看法认为种间杂种是罕见的，这种看法是无根据的。 来自辞典例句

3 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。

4 mule   

n.骡子，杂种，执拗的人

参考例句：

• A mule is a cross between a mare and a donkey.骡子是母马和公驴的杂交后代。
• He is an old mule.他是个老顽固。

5 bass   

n.男低音(歌手)；低音乐器；低音大提琴

参考例句：

• He answered my question in a surprisingly deep bass.他用一种低得出奇的声音回答我的问题。
• The bass was to give a concert in the park.那位男低音歌唱家将在公园中举行音乐会。