Genetically Engineered Rice Varieties Cut Use of Pesticides

A study in China suggests that two kinds of genetically engineered rice can reduce the costs, and dangers, of using pesticides.

One kind of rice includes a gene found in the bacterium known as Bt. Bt lives in soil and on plants; it is a natural insecticide. It is poisonous to some kinds of insects. Bt maize is commonly planted in the United States. The other kind of rice was engineered to resist insects with a gene from the cowpea plant.

The two-year study involved tests of Bt rice in Hubei province and cowpea rice in Fujian. Scientists collected information from small farms already testing insect-resistant rice without technical aid. Some farmers are growing both insect-resistant and traditional rice.

The scientists found that the Bt rice produced six to nine percent more grain than other kinds of rice. The cowpea rice, based on fewer observations, did not appear to increase productivity.

Still, the findings show that resistance to insects improved for both kinds of rice. The study says farmers used eighty percent less insecticide than usual.

Science magazine published the findings. Jikun Huang led the study. He is director of the Center for Chinese Agricultural Policy, in the Chinese Academy of Sciences.

The study notes that no country has yet released a major food grain crop that has been genetically changed. Engineered crops are now used mostly for animal feed and products like cotton.

The Chinese farmers in the study made their own decisions about when to use insecticides. Those with traditional rice crops used chemicals almost four times per growing season on average. But farmers with the insect-resistant rice used insecticides an average of less than once per season.

Less insecticide meant fewer sick farmers. The study says the farmers growing insect-resistant rice did not report any health problems from the use of poisons.

China has not approved genetically engineered rice for market. But a report from Hubei last month said insect-resistant rice appears to have been sold illegally for the last two years. That report came from the environmental group Greenpeace, which oppose genetic engineering. China says it is investigating the Greenpeace report.

Some countries will not import genetically engineered foods. Not everyone is sure that such products are safe for people or the environment.

Source:
VOA News Service
Author: Mario Ritter
First published: May 9, 2005

Scientists Complete a Genetic Map of Rice

Scientists now know a lot more about a grain that people have eaten for ten thousand years. Research teams around the world have completed a map of the genes of rice. Such a map is called a genome. The findings appeared last week in the magazine Nature.

The map represents 95% of the rice genome. And the information is considered 99.99% correct.

The aim is to speed up the improvement of rice. The scientists warn that the kinds of rice plants used now have reached the limit of their productivity. Yet world rice production must grow by an estimated thirty percent in the next twenty years to meet demand.

In their paper, the researchers say rice is an excellent choice for genetic mapping and engineering. Rice genes have only about three hundred ninety million chemical bases. That might sound like a lot. But other major food grains have thousands of millions.

The new map could better explain not just rice. Rice shares a common ancestor with other crops in the grass family. These include corn and wheat.

Also, rice shares more than 70% of its genes with Arabidopsis. This plant is in the mustard family. Its genome was completed in 2000.

Genes produce proteins which guide the building of organisms. Genes are placed along chromosomes. Rice has twelve chromosomes. The scientists found almost thirty-eight thousand genes. By comparison, studies have found only about twenty-five thousand genes in humans.

The International Rice Genome Sequencing Project in Tsukuba, Japan, led the research. The effort started in 1998.

The Rice Genome Research Program in Japan supervised the mapping of about half of the genome. American researchers were responsible for three chromosomes. Chinese and Taiwanese researchers mapped one each. A French group mapped one and part of another. Researchers in Brazil, Britain France, India, South Korea and Thailand also took part.

The project was expected to take ten years. But the work was finished in six because many of the groups shared information and technology. Two companies, Monsanto of the United States and Syngenta of Switzerland, also shared their research.

Source:
VOA News Service
Author: Mario Ritter
First published: August 15, 2005