官方APP下载:英语学习播客(支持苹果手机、安卓手机)
创办于2003年
UNSV记不住?那就记中文谐音“忧安思危”吧!
  Slow and Steady Wins the Race!
UNSV英语学习频道 - Slow and steady wins the race!
公众微信服务号
英语全能特训(微信公众服务号)
UNSV英语学习频道淘宝网店
客服短信:18913948480
客服邮箱:web@unsv.com
初级VIP会员
全站英语学习资料下载。
¥98元/12个月

AGRICULTURE REPORT - Unwrapping the Genetic Secrets of a Chocolate Bar

作者:Jerilyn Watson and Steve Baragona 发布日期:10-19-2010

Scientists have mapped the genetic code of two kinds of cacao or cocoa tree, which provide the beans used to make chocolate
Scientists have mapped the genetic code of two kinds of cacao or cocoa tree, which provide the beans used to make chocolate

This is the VOA Special English Agriculture Report.

Cacao or cocoa trees grow in hot, rainy areas of Africa, Asia and Central and South America. Their beans are used to make cocoa powder, cocoa butter and of course chocolate.

There are five to six million growers, maybe more. Many are poor family farmers with only a few hectares.

West Africa produces more than half of all cocoa beans. Ivory Coast leads the world in production, followed by its neighbor Ghana.

The trees are usually in their fifth year when they start to grow the pods that contain the beans. The trees produce the most pods when they are ten, but they are still productive long after that.

Workers use large knives to cut the lower pods and long tools to remove pods from high on the tree. Later they break open the pods to remove the beans.

A half-gram of chocolate requires about four hundred beans. The World Cocoa Foundation says an average pod contains twenty to fifty beans. And experts say growers can lose perhaps one-third of their harvest to diseases and insects.

But now scientists have genetic maps of two kinds of cocoa trees. These genomes are mostly complete and could lead scientists to new ways to increase production and prevent disease.

Mapping genes is the first step to understanding an organism. Next comes learning the job of each gene.

The American food company Mars took the lead in paying for mapping the genes of the Forastero cocoa tree. The Forastero provides eighty to ninety percent of the world's cocoa beans. Mars depends on those beans for its M&Ms and other chocolate candies.

The company's research partners included several universities and the United States Department of Agriculture.

The average West African cocoa farmer produces about four hundred kilos of beans per hectare. But Howard-Yana Shapiro, head of plant science and external research at Mars, thinks that science could greatly increase the yield.

HOWARD-YANA SHAPIRO: "There's a yield potential of maybe four thousand kilos, ten times what the average is in West Africa."

A competitor of Mars, Hershey's, supported the gene mapping of the Criollo, a far less common cacao tree. Cirad, a French government research center, led scientists from six countries in creating that genome.

We'll talk more about the cocoa industry next week, when we look at efforts to help child laborers in Ivory Coast and Ghana.

And that's the VOA Special English Agriculture Report, written by Jerilyn Watson and Steve Baragona. You can read and listen to our reports at www.unsv.com. And you can watch captioned videos on YouTube at VOA Learning English. I'm Bob Doughty.

版权所有©2003-2019 南京通享科技有限公司,保留所有权利。未经书面许可,严禁转载本站内容,违者追究法律责任。 互联网经营ICP证:苏B2-20120186
网站备案:苏公网安备 32010202011039号苏ICP备05000269号-1中国工业和信息化部网站备案查询
广播台