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WASHINGTON, May 2 (Xinhua) -- Rice originated in China, a team of U.S. genome researchers has concluded in a study tracing back thousands of years of evolutionary history through large-scale gene re-sequencing.Their findings, which appear Monday in the latest issue of the Proceedings of the National Academy of Sciences (PNAS), indicate that domesticated rice may have first appeared as far back as approximately 9,000 years ago in the Yangtze Valley of China. Previous research suggested domesticated rice may have two points of origin -- India as well as China.Asian rice, Oryza sativa, is one of world's oldest crop species. It is also a very diverse crop, with tens of thousands of varieties known throughout the world. Two major subspecies of rice -- japonica and indica -- represent most of the world's varieties. Sushi rice, for example, is a type of japonica, while most of the long-grain rice in risottos are indica.Because rice is so diverse, its origins have been the subject of scientific debate. One theory -- a single-origin model -- suggests that indica and japonica were domesticated once from the wild rice O. rufipogon.Another -- a multiple-origin model -- proposes that these two major rice types were domesticated separately and in different parts of Asia. The multiple-origin model has gained currency in recent years as biologists have observed significant genetic differences between indica and japonica, and several studies examining the evolutionary relationships among rice varieties supported more than domestication in both India and China.In the PNAS study, the researchers re-assessed the evolutionary history, or phylogeny, of domesticated rice using previously published datasets, some of which have been used to argue that indica and japonica rice have separate origins. Using more modern computer algorithms, however, the researchers concluded these two species have the same origin because they have a closer genetic relationship to each other than to any wild rice species found in either India or China.In addition, the study's authors examined the phylogeny of domesticated rice by re-sequencing 630 gene fragments on selected chromosomes from a diverse set of wild and domesticated rice varieties. Using new modeling techniques, which had previously been used to look at genomic data in human evolution, their results showed that the gene sequence data was more consistent with a single origin of rice.In the study, the investigators also used a "molecular clock" of rice genes to see when rice evolved. Depending on how the researchers calibrated their clock, they pinpointed the origin of rice at possibly 8,200 years ago, while japonica and indica split apart from each other about 3,900 years ago. The study's authors pointed out that these molecular dates were consistent with archaeological studies.Archaeologists have uncovered evidence in the last decade for rice domestication in the Yangtze Valley beginning approximately 8, 000 to 9,000 years ago while domestication of rice in the India's Ganges region was around about 4,000 years ago."As rice was brought in from China to India by traders and migrant farmers, it likely hybridized extensively with local wild rice," explained New York University biologist Michael Purugganan, one of the study's co-authors. "So domesticated rice that we may have once thought originated in India actually has its beginnings in China."

BEIJING, April 24 (Xinhua) -- The Chinese government has ordered food companies to keep clear and intact records of all their production and selling operations as part of the efforts to prevent the illegal use of food additives.All food manufacturing and management companies must examine all products in stock for any trace of illegal food additives and keep records of the results in accordance with laws and regulations, according to a circular released Sunday by the food safety committee under the State Council, or China's Cabinet.The circular came days after Vice Premier Li Keqiang warned of the great harm from illegal additives in food, promising "a firm attitude, iron-hand measures and more efforts" in dealing with the problem.Companies that fail to keep genuine and intact records and documents will be ordered to reform, and those providing fake records and certificates will be suspended from operations and punished accordingly, said the circular.According to the circular, it is strictly forbidden to produce and sell non-edible materials that are likely to be used in food production without official certificates, and authorized production companies of these materials must adopt a real-name selling system.These materials, including those banned in animal feed and drinking water, should not be sold to food and feed companies, the circular added.A series of food safety scandals emerged in China recently. In one of the latest cases, steamed buns in Shanghai were reported, last week, to have been dyed, sold past their expiration date, or laced with coloring additives to mislead consumers.

BEIJING, April 10 (Xinhua) -- While advocating Internet freedom worldwide, the U.S. imposes fairly strict restriction on cyberspace on its own territory, said the Human Rights Record of the United States in 2010 issued by the Information Office of China's State Council Sunday.The United States applies double standards on Internet freedom by requesting unrestricted "Internet freedom" in other countries, which becomes an important diplomatic tool for the U.S. to impose pressure and seek hegemony, and imposing strict restriction within its own territory, the report said.According to the report, on June 24, 2010, the U.S. Senate Committee on Homeland Security and Governmental Affairs approved the Protecting Cyberspace as a National Asset Act, which will give the federal government "absolute power" to shut down the Internet under a declared national emergency.

BEIJING, May 21 (Xinhua) -- China's State Food and Drug Administration (SFDA) issued a circular on Friday banning the use of Nimesulide, an anti-inflammatory drug, for children under the age of 12, considering potential side-effects such as liver and kidney damage.Nimesulide is a non-steroidal anti-inflammatory drug that first became available in Italy in 1985. It is now used in more than 50 countries and regions.The drug entered Chinese markets in 1997.According to the SFDA, while common adverse reactions to the drug include vomiting and stomache, domestic and overseas statistics indicate that more severe issues are related to the drug, such as blood coagulation disorders, decreased white blood cells and damage to liver and kidney.Previously, the SFDA only prevented the use of the drug among children one year old or younger.Also on Friday, the SFDA ordered the suspension of the production, sales and use of Duxil (almitrine and raubasine compound) due to its "unobvious" efficacy.According to the SFDA, clinical research found "little" evidence proving the drug effectively improves the cognitive ability for patients suffering vascular cognitive impairment.The drug was supposed to treat symptoms related to cognition and sensory nerve damage.The moves came after a two-month nationwide campaign was launched earlier this month to probe the quality of essential drugs and ensure drug safety.Official figures show that China's National Center for Adverse Drug Reaction Monitoring received 692,904 reports of adverse reactions in 2010, up 8.4 percent compared with those in 2009.Among the total, 109,991 cases involved new or severe adverse reactions, a year-on-year increase of 16.2 percent.

GUIYANG, Jan. 23 (Xinhua) -- Migrant workers, or off-farm workers, in China should enjoy paid annual family-visit vacations as their urban counterparts, a political advisor in southwest China's Guizhou Province had said."Localities could legislate on the issue on a trail basis," said Yu Peixuan, a member of the Guizhou Provincial Committee of the Chinese People's Political Consultative Conference (CPPCC), made this proposal at the political advisory body's annual session held Jan. 16-22.If migrant workers took paid home leave every year, they would have more time to help their wives in rural homes do the heavy farm work and educate their children, said Yu. "Thus, family ties would be cemented."Statistics show that 47 million women remain at home in rural China when adult males go off to cities to earn their livings.These women played an important role in taking care of the elderly people and children in their rural homes, but they also face many practical difficulties, such as heavy farm work and dull daily life.One of the major factors affecting these women's quality of life was the lack of communications with their husbands, said Yu.Yu called on large enterprises to allow migrant workers to take paid home leave first to set an example for other enterprises.According to the present Labour Law, regular workers at government organs, institutions and state-owned enterprises are eligible for paid vacations of one month per year to visit separated spouses in different cities or regions.

来源：资阳报