Boston: Scientists have the genetic information needed to create a new disease-resistant strain of ‘super rice’ that grows more crops using less polluting fertilizer, scientists said.
The challenge is how to put a mix of favourable genes into one productive strain, according to a report by Qifa Zhang, a geneticist at the National Key Laboratory of Crop Genetic Improvement in Wuhan, China. China and other countries that depend on rice need an environmentally benign, or green, variety of rice that maintains yields while abating fertilizer and pesticide pollution, Zhang said in the report on Monday in the Proceedings of the National Academy of Sciences. Chinese farmers use about one third of the world’s nitrogen, phosphorus and potassium fertilizer, he said.
“Everywhere we go, the water, river, ponds and lakes are polluted,” he said on Monday. “Even drinking water becomes a problem; that’s why we’re working very hard to develop green rice.”
Rice, the only cereal that can grow in water, is ideal for cultivation in areas that undergo annual monsoons and flooding. It’s the staple food in at least 24 countries and supplies 20% of the world’s dietary energy, compared with 19% for wheat and 5% for corn, according to the Food and Agriculture Organization (FAO) of the United Nations.
Rice production has been plagued by drought and pests such as stemborers and brown planthoppers, Zhang said. The cost of anti-stemborer spray and crop losses to the insect comes to about $1.5 billion (Rs5,955 crore) annually, according to the report. Increasing use of fertilizers also raises the cost of growing rice and makes plants more vulnerable to disease, Zhang said.
Paddies around the world will produce about 638 million tonnes of rice this year, just 1% increase from 2006, the FAO forecast in June. Zhang has been working for nine years to develop a super rice strain to help insulate low-income countries from shortfalls.
“We have been frequently approached by scientists from India and Bangladesh,” he said. “Now we’re also trying to collaborate with African scientists to develop rice for them.”
An international team of scientists deciphered the complete genome sequence of rice in 2002. At least 19 genes can give protections against brown planthoppers, and dozens help plants resist blight and fungus, Zhang said.
Other genes have been identified to help plants use nutrients and water more efficiently, he said.