. . .Can keep millions from going hungry. Great news if it proves out:
Rice is grown in flooded fields, usually to kill weeds. But rice plants do not like it when they are submerged in water for long periods, Ronald said.
“They don’t get enough carbon dioxide, they don’t get enough light and their entire metabolic processes are thrown off. The rice plant tries to grow out of the flood, but when it does, it depletes its sugar reserves. It starts to break down its chlorophyll, important for photosynthesis. It grows really quickly, and then when the flood recedes, it just dies. It’s out of gas.”
Normal rice dies after three days of complete flooding. Researchers know of at least one rice variety that can tolerate flooding for longer periods, but conventional breeding failed to create a strain that was acceptable to farmers.
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.
“This can be a problem for farmers,” Ronald said. “The varieties that were developed from conventional breeding were rejected by farmers because they didn’t yield well or taste good.”
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.”
This also throw into great disarray the projections of global deaths due to global warming induced famine.