Bangladeshi rice scientists have advanced a beta carotene-rich rice to a varietal release stage, heralding a new era in fight against vitamin-A deficiency (VAD).
They said the wait is nearly over for release of Golden Rice, a long touted remedy to VAD.
According to the World Health Organization's global VAD database, one in every five pre-school children in Bangladesh is vitamin A-deficient. Among the pregnant women, 23.7 percent suffer from VAD.
Upon receipts of positive outcome from two successive years of 'confined' field trials, the breeders at the Bangladesh Rice Research Institute (BRRI) have just gone for a final cycle of multi-location field trials and sought regulatory approval from the government for an 'unconfined' field test prior seeking variety release approval.
BRRI Senior Plant Breeder Dr M A Kader told UNB that in last Boro season they've got 10 to 12 μg/g (micrograms/gram) beta carotene in a BRRI dhan29 line genetically converted into Golden Rice, which should be enough to address half of rice-eating consumers' daily deficiency of vitamin-A.
"This season (Boro) we've gone for 'confined' field trials in five different agro-ecological locations again. Besides, we've also sought permission for an open field trial prior starting the process of varietal release," explained Kader, now overseeing the Golden Rice programme at BRRI.
Dr Donald J MacKenzie, Regulatory Affairs and Stewardship Leader of the Golden Rice Project of the International Rice Research Institute (IRRI), now on a visit to Bangladesh, told UNB that Bangladeshi rice scientists have advanced the beta carotene-rich rice to a stage very close to release of Golden Rice.
"The Philippines, Indonesia are also developing the Golden Rice but I think Bangladesh is marching ahead," said Dr Donald.
Beta carotene, also known as pro-vitamin A, is a substance that the human body can convert to vitamin A.
With this development, a long wait is nearly over for rice breeders who have been trying since 1999 for a varietal development and release of Golden Rice, long being touted by the scientist fraternity as a key remedy to acute VAD problem.
BRRI scientists analysed the post-harvest data collected from the first field test conducted on - 'GR2E BRRI dhan29' - during the 2015-16 Boro season and again the data generated from multi-location trials conducted in 2016-17 Boro season drawing a conclusion that the results are positive.
BRRI's Golden Rice Project Director Dr Partha S Biswas, now on a visit to IRRI, told UNB that 10 μg/g betacarotene in GR2E BRRI dhan29 is good enough to meet 50 percent of vitamin-A needs of people consuming rice in their daily diet.
The vitamin A-rich rice is named Golden Rice for its golden colour. It was first developed by splicing three foreign genes -- two from daffodil and one from a bacterium -- into japonica rice, a variety adapted to temperate climates. It is capable of producing beta carotene. But for a better beta carotene expression in rice, the daffodil genes were replaced by maize genes later in 2005.
None of the major diseases like blast, sheath blight, bacterial blight and tungro was observed in the transgenic GR2E BRRI dhan29 and the yield was on average 10 percent higher than that of the BRRI dhan29 (check variety) with good expression of beta carotene.
Although Bangladeshi rice scientists have been at the forefront of Golden Rice research since the development of this transgenic rice by Swiss and German scientists in 1999, the process gathered momentum only when then IRRI plant biotechnologist, Dr Swapan K Datta, infused the genes responsible for beta carotene into BRRI dhan29 in 2002-03.
The genetic engineering technology to derive vitamin A in rice was first applied by Prof Ingo Potrykus of Swiss Federal Institute of Technology in Zurich, and Prof Peter Beyer of the University of Freiburg, Germany back in 1999. All renowned journals and news magazines, including the Nature, the Science and the Time, covered the breakthrough in 2000.
The first generation Golden Rice (known as GR1) was developed through infusing genes from daffodil, but later the second generation variety (known as GR2) was developed by taking a gene from corn as it gave much better expression of pro-vitamin A.
Some six lines of GR2 (scientifically called "events") were developed and the IRRI chose to work on one called GR2R, which it developed and subsequently infused in Filipino and Bangladeshi rice varieties.
After years of lab and greenhouse tests on GR2R, the Philippines and Bangladesh eventually halted the process upon an IRRI advice that Event GR2E would work better.
Golden Rice co-inventor Prof Peter Beyer told this correspondent that there were some problems with the Event GR2R. He said the new Event should work well.
Swapan K Datta, ex-IRRI scientist who infused beta carotene-producing genes into Bangladesh's best performing rice variety, BRRI dhan29, said he was looking forward to see Golden Rice goes to farmers' fields.
The BRRI dhan29, developed by BRRI in 1994, is the most productive dry season rice variety of Bangladesh that has gone beyond national boundaries to be grown in many other countries including India, China, Vietnam, Nepal, Bhutan and Myanmar.
Rice does not contain beta carotene. Therefore, dependence on rice as the predominant food source necessarily leads to vitamin-A deficiency, most severely affecting small children and pregnant women.
Consumption of only 150 gram of Golden Rice a day is expected to supply half of the recommended daily intake (RDA) of vitamin A for an adult. People in Bangladesh depend on rice for 70 percent of their daily calorie intakes.
The IRRI says VAD is the main cause of preventable blindness in children and globally, some 6.7 million children die every year and another 3,50,000 go blind because they are vitamin-A deficient.
In April 2011, Seattle-based Bill and Melinda Gates Foundation sanctioned a grant of over $10 million to IRRI to fund, develop and evaluate Golden Rice varieties for Bangladesh and the Philippines. Later further funding was also made available.
Officials concerned at IRRI and Gates Foundation said as the Golden Rice inventors and subsequent technology developer Syngenta allowed a royalty-free access to the patents, the new rice would be of the same price as other rice varieties once released for commercial farming in Bangladesh, and farmers would be able to share and replant the seeds as they wish.
Even though it must be taking Bangladesh few more months to start the Golden Rice release process, two countries - Australia and New Zealand - already cleared this biotech rice product for consumption in those countries both as food and feed while a review is underway in the United States by the Food and Drug Administration (FDA), said Dr Donald J MacKenzie.
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