Indo-US team develops rice with higher protein content

Indo-US team develops rice with higher protein content
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First Published: Thu, Jan 24 2008. 12 28 AM IST

Updated: Thu, Jan 24 2008. 12 28 AM IST
New Delhi: A team of Indian and American scientists has successfully developed a rice hybrid that will have 12% more protein content—a significant discovery at a time when the government is trying to enhance nutrition levels among the country’s population.
Though a host of tests still remain, this will be the largest ever protein boost registered in rice involving Indian varieties, claim scientists involved with the project. The maximum protein increase in Indian varieties range from 5-9%.
Current hybrid varieties in India focus on boosting yield and pest resistance, but with increasing concerns on nutrition levels in the population, relative decline of arable land and the rising popularity of rice over wheat, boosting levels of certain proteins has become a top priority for the government.
Rice, India’s most widely produced crop, accounts for about 43%, (80 million tonnes out of 184 million tonnes) of foodgrain production in the country, according to figures from the agriculture ministry and takes up 31% of the total land under agriculture (43.7 million hectares out of 140.88 million hectares).
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The government recently announced a Rs500 crore crop designing strategy, that will look at increasing the nutrient levels of a host of food crops such as rice, wheat and a range of pulses.
The research results, presented in this week’s peer-reviewed Journal of Agricultural Food Security, published by the American Chemical Society, involve plant geneticists S. Sukumar of the Tamil Nadu Agricultural University, and Ahmed Mahmoud and B. Harikrishnan of the University of Missouri, Columbia.
The project received funding from the Rockefeller Foundation and a grant from the Indian government’s department of biotechnology, or DBT.
Initial tests, the researchers say, show the rice variety as having 19.5% more lysine and 19.4% more threonine, two of the nine amino acids considered essential for the body. These amino acids are not generated by the human body but are obtained from food intake. Amino acids are the building blocks of proteins.
Hybrid varieties are created by crossing genetically dissimilar varieties of a species. Thus, a variety that’s high yielding when crossed with another, which is low-yielding but grows well in saline water conditions, is expected to result in a variety that has both characteristics.
But it’s rarely as simple as that, because these hybrids end up acquiring other unfavourable traits, too. Another pitfall is that the genetic structure of the crossed varieties becomes unstable over subsequent crossings. Thus scientists repeatedly cross hybrids, sometimes over a 100 generations to develop a variety with desired properties, a time consuming approach.
Sukumar’s hybrid was created by crossing a wild rice variety from the Philippines from the International Crop Research Institute, an inter-governmental consortium, and a IR-64, a local Indian variety known for its high yield and taste.
“Most importantly, repeated crossings have shown that protein content doesn’t change even after subsequent crossings across generations,” said Sukumar.
Merely increasing protein content in a grain is useless, as a host of other factors such as yield, taste, and softness after being cooked, are all relatively important for a rice variety to be declared successful, B. Sivakumar, former director of the National Institute of Nutrition, Hyderabad, said.
“Golden Rice, a transgenic (where a gene from a foreign plant is inserted into the grain) rice claimed to have increased levels of beta-carotenes (vital to production of vitamin A), but it was yellowish in colour, which farmers found unacceptable,” Sivakumar said.
Unlike Golden Rice, the new hybrid rice is not a transgenic.
Tests on the hybrid’s yield and its performance in various kinds of soil have begun at TNAU, and that would be the ultimate measure of the variety’s true potential.
“Yes, tests remain but we are quite confident that the yield levels won’t be affected because the wild species in question, is naturally hardy and stable over subsequent generations,” said Sukumar
The government recently announced a variety of maize, again formed by crossing a native variety with a wild species, that was high in protein content.
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First Published: Thu, Jan 24 2008. 12 28 AM IST
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