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Broadcast: January 7, 2003
By Mario Ritter
This is the VOA Special English Agriculture Report.
Rice is the world's most important crop. Much has been done to increase its productivity. Modern genetic science has tried to change the genes of rice to improve it. However, traditional methods for growing rice also have been very successful. Today, we show that both methods for improving crops are needed.
Recently, Ray Wu of Cornell University in Ithaca, New York and other researchers tried to create a kind of rice that is able to grow in difficult conditions. They discovered genes from the e-coli bacterium1 that help plants make a special sugar called trehalose. The sugar is believed to help organisms remain healthy in difficult or dry conditions.
The Cornell team engineered genes of basmati rice to accept the gene that helps form the special sugar. The team reported that the genetically engineered basmati rice was able to survive in salty soil, at low temperatures and during dry periods.
The scientists say the new rice will be able to feed people even during periods of dry weather and in areas with increasingly salty water.
However, not all genetic change is produced by combining genes from very different organisms. Olga Linares of the Smithsonian Tropical Research Institute has shown that traditional agricultural methods remain important. She reported to the National Academy of Sciences that a new rice would have been impossible without traditionally grown African rice.
There are two kinds of rice in the world - Asian rice and African rice. Mizz Linares notes that about eighty percent of the rice grown in Africa is Asian rice. Only fifteen percent is native African rice. However, researchers at the West African Rice Development Association in Ivory Coast were able to combine African rice with Asian rice to create what is called a hybrid. The new rice plant is called NERICA, or "New Rice for Africa." The new rice is able to survive difficult conditions, like long periods of dry weather.
The plants also produce more rice and can help increase food production. In southern African countries, food production has decreased since the nineteen-sixties. Many experts see NERICA rice as a way to solve that problem. Yet, NERICA would not have been possible if farmers in Senegal had not continued growing their traditional crops.
1． bacterium [bAk5tIErIEm] n. 细菌
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