久久亚洲国产成人影院-久久亚洲国产的中文-久久亚洲国产高清-久久亚洲国产精品-亚洲图片偷拍自拍-亚洲图色视频

您現在的位置: Language Tips> Audio & Video> Special Speed News  
   
 





 
Researchers seek drought-resistant crops
[ 2008-06-03 10:54 ]

 

Download

This is the VOA Special English Agriculture Report.

One cause of the current food crisis is drought. Food prices are high in part because of dry weather in places as far distant as Spain and Australia.

Around the world, the amount of land affected by drought has doubled in the past thirty years. So says the National Center for Atmospheric Research in the United States. And scientists concerned about climate change believe it will cause more drought in many areas in the future.

A lot of research is going into efforts to develop drought-resistant crops. One project involves tobacco plants genetically engineered to keep their leaves during water shortages.

Eduardo Blumwald and Rosa Rivero at the University of California, Davis, led a team from the United States, Japan and Israel. Rosa Rivero says they chose tobacco because it has big leaves. Also, it grows fast and has structural similarities with some other plants.

The researchers did an experiment with two groups of tobacco plants. They worked with a set of normal plants and a set of transgenic plants. These had a gene added to interfere with the biological causes of leaf loss during drought.

The researchers put all the plants in a greenhouse to grow under normal conditions for forty days. Then, for fifteen days after that, the plants did not receive any water.

The normal plants lost their green color. Finally, they lost their leaves. But the researchers say the transgenic plants kept their leaves and their color.

After the fifteen dry days, all the plants were watered again for a week. The transgenic plants returned to normal growth, and their seed production was close to normal. But the other plants all died.

Rosa Rivero says the transgenic plants kept a relatively high water level. They also continued to produce energy during the dry period, although at a reduced level. The amount of seeds they produced was close to normal.

In addition, the researchers found that the plants could survive on only thirty percent of the normal amount of irrigation water. Yield loss was minor, they said.

The findings appeared late last year in the Proceedings of the National Academy of Sciences. The University of California has applied for patent protection for the technology.

The researchers expect to move forward with field testing of the transgenic tobacco in late August. They hope for similar results with crops like tomatoes, rice, wheat and cotton.

And that's the VOA Special English Agriculture Report, written by Jerilyn Watson. I’m Steve Ember.

(Source: VOA 英語點津姍姍編輯)

 
英語點津版權說明:凡注明來源為“英語點津:XXX(署名)”的原創作品,除與中國日報網簽署英語點津內容授權協議的網站外,其他任何網站或單位未經允許不得非法盜鏈、轉載和使用,違者必究。如需使用,請與010-84883631聯系;凡本網注明“來源:XXX(非英語點津)”的作品,均轉載自其它媒體,目的在于傳播更多信息,其他媒體如需轉載,請與稿件來源方聯系,如產生任何問題與本網無關;本網所發布的歌曲、電影片段,版權歸原作者所有,僅供學習與研究,如果侵權,請提供版權證明,以便盡快刪除。
相關文章 Related Story
 
 
 
本頻道最新推薦
 
Walking in the US first lady's shoes
“準確無誤”如何表達
英國新晉超女蘇珊大媽改頭換面
豬流感 swine flu
你有lottery mentality嗎
翻吧推薦
 
論壇熱貼
 
別亂扔垃圾。怎么譯這個亂字呀?
橘子,橙子用英文怎么區分?
看Gossip Girl學英語
端午節怎么翻譯?
母親,您在天堂還好嗎?

 

主站蜘蛛池模板: 久久综合色播 | 99久久精品国产亚洲 | 久久亚洲欧洲日产国码 | 手机看片国产免费久久网 | 美女视频永久黄网站免费观看国产 | 午夜精品久视频在线观看 | 国产高清视频免费 | 欧美一级做一a做片性视频 欧美一级做一级爱a做片性 | 亚洲欧美国产视频 | 亚洲国产成人在线观看 | 亚洲欧美一区二区三区在线播放 | 91原创视频在线观看 | 美女网站在线观看视频18 | 日韩一级一欧美一级国产 | 秋霞手机入口二日韩区 | baby在线观看免费观看 | 亚洲欧美日本人成在线观看 | 亚洲九九香蕉 | 亚洲性爰视频 | 日产一一到六区网站免费 | 久久人 | 久视频免费精品6 | 中文字幕一二区 | 三级手机在线观看 | 明星国产欧美日韩在线观看 | 成人看片在线观看免费 | 亚洲毛片视频 | 毛片在线免费观看网站 | 国产网站在线看 | 欧洲美女与男人做爰 | 欧美人成一本免费观看视频 | 99精彩视频| 日韩在线观看视频免费 | 9久9久女女热精品视频免费观看 | 美国免费高清一级毛片 | 国产做a爰片久久毛片 | 国产美女高清一级a毛片 | 久久精品国产线看观看亚洲 | 日韩中文字幕在线观看 | 中日韩一区二区三区 | 亚洲爱爱天堂 |