Combatting Hunger: Flood-Tolerant Rice Increases Yield Three- to Five-Fold

CNN reports a really creative advance in the fight against world hunger: three scientists, two from campuses of the University of California, have proven that a new flood-tolerant rice they developed multiplies the yield of rice fields three to five times. They expect that will make a significant dent in the 4 millions tons farmers lose each year to flooding. Excerpts from the CNN story follow:

If every scientist hopes to make at least one important discovery in her career, then University of California-Davis professor Pamela Ronald and her colleagues may have hit the jackpot.

Ronald's team works with rice, a grain most Americans take for granted, but which is a matter of life and death to much of the world. Thanks to their efforts to breed a new, hardier variety of rice, millions of people may not go hungry.

About half the world's population eats rice as a staple. Two-thirds of the diet of subsistence farmers in India and Bangladesh is made up entirely of rice. If rice crops suffer, it can mean starvation for millions.

"People [in the United States] think, well, if I don't have enough rice, I'll go to the store," said Ronald, a professor of plant pathology at UC-Davis. "That's not the situation in these villages. They're mostly subsistence farmers. They don't have cars."

As sea levels rise and world weather patterns worsen, flooding has become a major cause of rice crop loss. Scientists estimate 4 million tons of rice are lost every year because of flooding. That's enough rice to feed 30 million people.

So Ronald and her colleagues -- David Mackill, senior scientist at the International Rice Research Institute in the Philippines and Julia Bailey-Serres, professor of genetics at the University of California-Riverside -- spent the last decade working to find a rice strain that could survive flooding for longer periods.

Mackill identified a flood-resistant gene 13 years ago in a low-yielding traditional Indian rice variety. He passed along the information to Ronald, who isolated the gene, called Sub1, and introduced it into normal rice varieties, generating rice that could withstand being submerged in water for 17 days.

The team relied on something called precision breeding, the ability to introduce very specific genes into plants without the associated baggage of other genes that might tag along in conventional breeding.

Using precision breeding, scientists introduced the Sub1 gene three years ago into test fields in Bangladesh and India. The subsequent rice harvests were a resounding success.

"The results were really terrific," said Ronald. "The farmers found three- to five-fold increases in yield due to flood tolerance. They can plant the normal way. They can harvest the normal way and it tastes the same. Farmers had more food for their families and they also had additional rice they could sell to bring a little bit of money into the household."

"The potential for impact is huge," agreed Mackill in a statement on the IRRI Web site. "In Bangladesh, for example, 20 percent of the rice land is flood prone and the country typically suffers several major floods each year. Submergence-tolerant varieties could make major inroads into Bangladesh's annual rice shortfall."

The researchers anticipate that the flood-tolerant rice plants will be available to farmers in Bangladesh and India within two years.

But Ronald has no plans to rest on her laurels.

"I feel a great sense of gratitude that I was able to contribute in this way," she said. "But the farmers have asked us, 'Can you develop varieties that are drought tolerant, salt tolerant? Can you develop varieties that are insect resistant?' There are always more things to work on."