|
| all news articles | by topics |
|
news
articles about singapore's wild places
|
| see
also BBC Online, 10 Aug 05 Rice genome unravelled at last PlanetArk website, 11 Aug 05 Scientists Map Rice Genome, Predict Higher Yields Story by Gideon Long LONDON - Scientists claimed a major breakthrough on Wednesday in the drive to produce rice more cheaply and efficiently, saying they had completed the first map of the cereal's genome, or genetic code. That should allow agriculturalists to increase rice yields, potentially benefiting billions of people who rely on the crop as their main food source. "This is a breakthrough of inestimable significance, not only for science and agriculture but also for all those people who depend on rice as their primary dietary staple," said Joachim Messing, one of the scientists involved in the project. Researchers from 10 countries worked together to identify all 37,544 genes in rice and establish the position of each gene on rice's 12 chromosomes. They said they had identified some particularly important genes which might increase yield and productivity. Private companies Monsanto and Syngenta, among others, had previously produced partial sequences which led to genetic modification of rice but had not been able to draw up a full model. The two companies gave their draft sequences to scientists from the International Rice Genome Sequencing Project (IRGSP), a public consortium which finished the job. "The genetic map will greatly speed the hunt for genes that increase yield, protect against disease and pests or provide drought-resistance in rice and other cereal crops," said Robin Buell, the IRGSP's lead investigator. The IRGSP says the implications are enormous simply because rice is so essential to so many people. According to the United Nations, rice supplies 20 percent of the world's dietary energy supply. In Asia, more than 2 billion people obtain 60-70 percent of their calories from rice or rice-derived products. With populations growing in the developing world, rice is set to become even more important. Consumption trends suggest that 4.6 billion people will be reliant on it by 2025 compared to around 3 billion now. That means rice production will have to grow by around 30 percent to keep up with demand. Experts say the mapping of the rice genome also has implications for the production of other cereals. Messing, the director of a microbiology institute at one of the 32 institutions involved in the IRGSP, described the rice genome as "the Rosetta Stone of all the bigger grass genomes". BBC Online, 10 Aug 05 Rice genome unravelled at last Scientists have unscrambled the genetic code of rice, a development that could help end hunger around the world, Nature magazine reports this week. The blueprint will speed up the hunt for genes that improve productivity and guard against disease and pests. In order to avoid shortages, rice yields must increase by 30% over the next 20 years, researchers say. Scientists from 10 countries cooperated to work out how the 400 million "letters" of rice DNA are arranged. "Rice is a critically important crop, and this finished sequence represents a major milestone," said Robin Buell of The Institute for Genetic Research (TIGR). "We know the scientific community can use these data to develop new varieties of rice that deliver increased yields and grow in harsher conditions." Increasing demand The research will also help scientists understand other vital food crops. Rice is genetically similar to maize, wheat, barley, rye, sorghum and sugarcane. So understanding the genomes of these plants is now a small step away. "Rice is the Rosetta Stone for crop genomes," said Dr Buell. "We can use the rice genome as a base for genomic studies of cereals." According to the United Nations, rice currently provides 20% of the world's dietary energy supply, while wheat supplies 19% and maize 5%. Although rice represents 30% of global cereal production today, and production levels have doubled over the past 30 years, much more of the cereal will be needed in the future. Current consumption trends suggest that about 4.6 billion people will be reliant on rice by the 2025. In addition, global warming may mean that rice is required to be more robust in the face of droughts. Disease control It took seven years to complete the work and the results are already accelerating discovery. Scientists have used the sequence to identify genes that control fundamental processes, such as flowering. Rice's similarity to barley has also helped researchers identify genes responsible for resistance to barley powdery mildew and stem rust, two major crop diseases. "Now that we know where all the genes are, we try to associate them with certain traits," said Rod Wing of the University of Arizona. "The accurate, map-based sequence has already led to the identification of genes that confer important traits such as yield and demand for light during growth." The researchers compared rice to the only other fully sequenced plant genome, Arabidposis thaliana , or thale cress, a weed that is commonly used in laboratories. They found that while 90% of thale cress proteins also occur in rice, only 71% of rice proteins also occur in thale cress. This suggests rice has many genes specific to itself, or cereals. "By sequencing rice we sequenced all the other cereals to a certain extent," said Professor Wing. "Many of the shared genes are in similar positions on the respective chromosomes, so when we assign a function to a given gene in rice, it is very likely that the corresponding gene in another cereal has the same or a similar function." links Related articles on Global: general environmental issues |
| News articles are reproduced for non-profit educational purposes. | |
website©ria tan 2003 www.wildsingapore.com |