Researchers training rice farmers on how to handle diseases and pests in the field
Credit: Ivan Mallari/IRRI
BEIJING, 11 August 2006: Scientists have identified a gene that enables rice to survive for up to two weeks underwater, raising the possibility of breeding varieties that can withstand what would otherwise be damaging floods.
A quarter of the world's rice grows in areas prone to flooding, which costs rice farmers in South and South-East Asia more than US$1 billion a year. Although rice thrives in standing water, most varieties die within a week of being completely submerged. But others can tolerate being totally submerged for up to two weeks.
The researchers, who published their findings today in the British journal, Nature, studied the DNA of one such variety. They found it has a gene that intolerant varieties lack.
When they introduced the gene into a high-yielding rice variety grown widely in Asia, they found it kept its high yield but could also tolerate being totally submerged.
Rice geneticist and study co-author David Mackill of the International Rice Research Institute in the Philippines, and Pamela Ronald of the University of California in Davis, United States, led the international team.
Mackill said that scientists would be able to crossbreed submergence-tolerant rice with varieties that are already popular with farmers. "For half a century, researchers have been trying to introduce submergence tolerance into the commonly grown rice varieties through conventional breeding," he said.
"Globally, rice is the most important food for humans, and each year millions of small farmers in the poorest areas of the world lose their entire crops to flooding," said Pamela Ronald, a rice geneticist and chair of university's plant genomics program.
"Our research team anticipates that these newly developed rice varieties will help ensure a more dependable food supply for poor farmers and their families," she added. "And, in the long run, our findings may allow rice producers in the United States to reduce the amount of herbicides used to fight weeds."
with Cosmos Online
