On Monday, the Genetic Engineering Appraisal Committee (GEAC), which approves proposals relating to trials and commercialisation of genetically modified (GM) crops, placed in the public domain a safety assessment report on a transgenic mustard hybrid developed by scientists at Delhi University led by its former vice-chancellor Deepak Pental. The report, prepared by an experts’ subcommittee constituted by the official biotech regulator, concluded that consumption of the said GM mustard was “safe for human and animal health”, and its commercial release wouldn’t “pose any risk to biodiversity and the agro-ecosystem”.
So, is the approval for commercial cultivation of GM mustard a mere formality now, with the GEAC’s own expert panel giving it the green signal?
Well, the subcommittee’s 133-page report has been put on the GEAC’s web site to invite public feedback. These would then be reviewed by both the subcommittee and the GEAC, before a final decision is taken. Since a one-month period has been given for receiving comments, an approval by mid-October should provide reasonable time to plant the transgenic mustard in the coming rabi season for commercial seed production and multiplication. Largescale cultivation by farmers can follow in 2017-18. But we know from past experience that GM crop clearances are never a smooth affair. The best example here is Bt brinjal, where the GEAC’s go-ahead for its commercial release was overturned in February 2010 by the then Environment Minister Jairam Ramesh — who assumed the role of regulator himself and ordered a moratorium on the transgenic vegetable’s cultivation.
If all goes well, will this be the first GM food crop that Indian farmers will plant?
In a narrow sense, yes. The only transgenic crop currently being grown in the country is Bt cotton, which is a ‘non-food’ crop to the extent that the white fibre or lint from it isn’t eaten. But lint accounts for just about a third of the kapaas or raw un-ginned cotton that farmers harvest. The balance two-thirds comprises the cotton seed that is crushed in order to extract oil, and de-oiled cake or meal. Cottonseed oil is, in fact, India’s second largest indigenously produced edible oil today, after mustard. The de-oiled cottonseed meal, which contains about 40% protein, is similarly fed to cattle and buffaloes. That makes Bt cotton no less a food crop, as the oil from its seeds and the milk from the animals fed on its de-oiled cake are already being consumed by us. And we have been having this so-called “poison” since 2002, when Indian farmers started cultivating Bt cotton!
What then is this debate over ‘food’ versus ‘non-food’ in GM crops?
It is flawed, when used to draw a distinction between cotton and mustard on supposed grounds of the latter being a ‘food crop’. Bt cotton incorporates foreign genes isolated from Bacillus thuringiensis, a commonly occurring soil bacterium. The same goes for the GM mustard bred by the Delhi University scientists — it contains two genes (‘Barnase’ and ‘Barstar’) from a soil bacterium called Bacillus amyloliquefaciens, and a third gene (‘Bar’) derived from another non-pathogenic bacterium, Streptomyces hygroscopicicus. Just as nothing calamitous has happened to us from ingesting Bt proteins all these years, there is no evidence of the Barnase, Barstar and Bar proteins being toxic to either humans or animals. For the GM mustard, toxicity and allergenicity assessment studies were specifically carried out at the National Institute of Nutrition, Hyderabad, based on a 90-day feeding of leaves and seeds from it to laboratory rats. These did not reveal any ill effects in terms of the relevant measured parameters.
It is important to point out here that India annually imports over 3.5 lakh tonnes (lt) of canola oil, a lot of which is GM, and based on the same Barnase-Barstar-Bar gene technology. This is over and above the 30 lt imports of soyabean oil that is entirely GM. There have been no protests against such videshi GM oil by so-called swadeshi and green groups, who have directed all their protests against GM mustard, despite it being a product of indigenous, publicly-funded research.
And what exactly is the GM mustard that the DU scientists have developed?
Breeders have for long exploited a phenomenon known as ‘heterosis’ or the hybrid vigour that often comes from crossing genetically dissimilar plant varieties even within the same species. The first-generation or ‘F1’ offspring from such crosses tend to have yields higher than what either of the parents is individually capable of giving. Deepak Pental’s team at the Centre for Genetic Manipulation of Crop Plants at Delhi University was able to demonstrate the significant heterosis potentially resulting from crossing Indian mustard cultivars with their East European-origin relatives like ‘Early Heera’ and ‘Donskaja’.
But the problem with mustard is that its flowers contain both female and male reproductive organs, making the plants largely self-pollinating. When the egg cells of one plant cannot be easily fertilised by the pollen grains from another, the scope for developing hybrids through crossing of parents from divergent genetic pools is restricted.
This is where GM technology comes in. The Barnase gene alluded to earlier, codes for a protein that impairs pollen production. The plant into which it is incorporated, then becomes male-sterile, and capable of receiving pollen from another parent. That plant, in turn, contains the Barstar gene, which blocks the action of the Barnase gene. The resultant F1 progeny is both high yielding and can also produce seed/grain, thanks to the Barstar gene in the second male-fertile line. Using this technology, the Delhi University scientists bred DMH-11, a GM hybrid obtained from crossing an Indian mustard variety, Varuna (‘Barnase’ line), with Early Heera-2 (‘Barstar’). DMH-11 has reported a roughly 30% yield advantage over the Varuna ‘check’ variety in the bio-safety research level field trials carried out between 2010-11 and 2014-15.
Is that significant? Critics claim there are non-GM mustard varieties that give higher yields than DMH-11.
They are missing the point. GM technology, more than anything else, expands the scope of breeding in mustard, which is otherwise hampered by it being a naturally self-pollinating plant. DMH-11 could just be the start, as the Barnase-Barstar system can enable the development of hybrids from a wide range of Indian and East European mustards. These may not only yield higher levels of heterosis, but also help introduce other traits such as resistance to alternaria blight or stem rot diseases that is limited through conventional breeding.
India, moreover, needs to also boost its edible oil production, which, in 2015-16, was estimated at a mere 72 lt, as against imports of 160 lt. Out of the 72 lt, mustard’s contribution alone was 18.6 lt, followed by cottonseed oil at 12.4 lt (which is almost fully Bt). Opponents of GM mustard may inadvertently be helping the cause of edible oil imports, which cost the country $ 10.5 billion in foreign exchange last year.