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Pollen can travel farther than thought
文章来源: 文章作者: 发布时间:2006-05-23 字体: [ ]

By Mario Ritter

 

 Listen to this story

This is Gwen Outen with the VOA Special English Agriculture Report.

Wind plays an important part in the reproduction of many crops. In some cases, though, the effect can be surprising. A study recently appeared in the Proceedings of the National Academy of Sciences. This study involved a genetically engineered kind of grass.

Scientists found that pollen from the grass spread up to 21 kilometers to fertilize other grasses. This was true of plants grown for the experiment. The scientists say they found similar evidence of gene flow in wild plants up to 14 kilometers away. Earlier studies of genetically engineered plants had found pollination at distances of one kilometer or less.

Scientists from the United States Environmental Protection Agency led the new study in the state of Oregon. The team planted a kind of grass engineered to resist RoundUp, a poison that kills weeds.

Two companies, Monsanto and Scotts, developed this kind of creeping bentgrass for use on golf courses. Scotts also wants to market the grass for home use. There are concerns that the genetically engineered bentgrass could pass its chemical resistance genes to wild grasses or weeds.

In Hawaii, some fruit growers face a similar issue that involves papaya trees. These growers do not use chemicals or biotechnology. But tests have found genetically engineered seeds in their papayas. The organic growers say this is the result of pollen from genetically engineered papaya trees on nearby farms. Those trees were designed to resist a virus that was destroying Hawaii's papaya crop.

Now, the industry has come back to life. But the New York Times told how one organic grower reacted after tests showed that some of his fruit contained the genetically engineered seeds. He cut down all 170 of his trees. He has planted new ones, although the same thing could happen again.

Some plant scientists say farmers should not worry too much about problems from so-called genetic pollution. They say plants do not easily pass genetic qualities to other organisms in the wild. They say this is especially true of a single quality, like resistance to chemicals.

Still, the age-old spread of pollen in the wind is a modern issue in the debate over biotechnology.

This VOA Special English Agriculture Report was written by Mario Ritter. This is Gwen Outen.    

Vocabulary:
 

pollination: transfer of pollen from the anther to the stigma of a plant(授粉)

papaya: an evergreen, usually dioecious, tropical American tree (Carica papaya) having a crown of palmately divided leaves with pinnate lobes and large, yellow, edible fruit(番木瓜树)


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