VOA慢速英语20061128a

AGRICULTURE REPORT - Genetic 1 Map Could Point Way to an Improved Honey BeeBy Jerilyn Watson

Broadcast: Tuesday, November 28, 2006

This is the VOA Special English Agriculture Report.




Scientists now have a genetic map of the world's most important insect -- important to the food supply. The results showing the order, or sequence, of ninety-eight percent of the honey bee genome created a buzz of excitement. Understanding how a honey bee is designed should help scientists produce stronger bees.

Honey bees are the world's major source of pollination 2 for food, fiber 3 and oilseed crops. Bees gather nectar from flowers; the liquid gives them food and material to make honey. As they land, their bodies pick up and drop off fine particles of pollen 4. Most flowering plants need pollination to reproduce.

But Kevin Hackett, an official at the United States Department of Agriculture, noted 5 that the world's honey bee population is decreasing. He called the sequencing of its genome a powerful tool for fighting back against the causes.

One cause is the varroa mite 6 which can kill young bees even before they leave their eggs. Another is the tracheal mite which nests in the breathing tube of adult bees.

Some people think that insect poisons have also played a part in reducing bee populations.

Experts say honey bees are responsible for as much as twenty thousand million dollars worth of food production in the United States alone. But scientists have estimated that the bee population in the United States fell by fifty percent over the past half-century.

The main results of the Honey Bee Genome Sequencing Project Consortium appeared in the journal Nature. This international team is led by human-genome researchers at Baylor College of Medicine in Houston, Texas. Related reports appeared in other publications.

Like humans, bees have genes 7 that give them a sense of day and night. Scientists believe this helps honey bees gather food.

Bees find flowers by smell. Bees have more genes for a sense of smell than other insects whose genes have been mapped. But one of the project scientists noted they have fewer genes for taste. He thinks this might help them avoid pesticides 8 and plant diseases to find food.

The genetic research suggests that honey bees came from Africa. Their brains have similar genetic parts as the fruit fly. But fruit flies like to be alone. Scientists are interested in how, over millions of years, honey bees developed the complex social order in which they live.

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