Genetically modified (GM) Mustard hybrid will boost production and productivity
31st October, 2022, New Delhi
Mustard (Brassica juncea) is an important oilseed crop of India, grown in around 6-7 million ha area during the rabi season mostly in the states of Rajasthan, Haryana, Punjab, and Madhya Pradesh. Currently, India has a deficit of edible oils by almost 55-60 per cent of the total consumption. In the financial year 2020-21, around 13.35 million tonnes of edible oils were imported at a total cost of around Rs 117,000 crores in foreign exchange. India desperately requires an increase in the productivity of oilseed crops grown in the country. The average mustard yield in India is 1.0-1.3 tonnes/hectare. This is stagnant for almost two decades. Globally, yields of rapeseed have considerably increased with the introduction of hybrids. More than 90% of the rapeseed crop in Canada, grown in around 8.7 million ha, is under hybrids. Most of the rapeseed grown in China and Europe is also hybrids.
Mustard is predominantly a self-pollinating crop with flowers having both male and female parts. A robust pollination control system is required that would facilitate cross-pollination to help develop hybrids between any two selected diverse parental lines. Such a system has been developed by the Centre for Genetic Manipulation in Cop Plants, University of Delhi, which used three transgenes – barnase, barstar, and bar (the bar gene confers resistance to herbicide Basta and is needed for selecting the transformed lines). The Barnase gene is specifically expressed in the tapetum cells using a tapetum-specific gene promoter TA29. The tapetum provides nutrients to the developing pollens. The Barnase gene product is an RNase enzyme, which kills the tapetum resulting in pollen degeneration leading to male sterility. This causes male sterility in the resultant transgenic plant. Such transgenic parental line (Event Var bn 3.6) is then used as a female parent and fertilised by another parent (Event EH-2 modbs2.99 harbouring the Barstar gene) to develop the hybrid. Barstarcompletely negates the effect of the Barnase protein; as a consequence, the hybrid seed between the two lines is fully fertile and the farmers can reap the benefit of higher yield from the hybrid. The first hybrid developed using the GE pollination control mechanism is DMH-11. The trials conducted over three yearsat eight locations under the supervision of ICAR-DRMR, Bharatpurshowed DMH-11 to have,on average,a yield advantage of 28% over the megavarietyVaruna and 37% over the zonal checks. With the availability of a robust pollination control system in mustard, the way is clear for developing even higher yielding and canola quality hybrids.
Thus, hybrid DMH-11 could safely be grown in the farmers’ fields. Now that GM mustard has been given environmental clearance by The Ministry of Environment, Forests and Climate Change (MoEF&CC), Government of India, urgent efforts are needed to test DMH-11 hybrid at different locations in mustard belt by ICAR and State Agricultural Universities (SAUs). This be done in this growing season by ICAR-DRMR and the Department of Agriculture, MOA&FR. Using the available seed, around 100 demonstrations could easily be conducted in the current rabi season and efforts are needed to produce more hybrid seed through public-private partnership so that larger area could be covered in the next cropping season.
The decision to release GM mustard will encourage more research and innovations to reduce the environmental footprints of agriculture, develop climate resilient crops, and thereby assure food and nutritional security of the country.
It will also accelerate breeding efforts to produce new high yielding disease and pest resistant hybrids using this new technology cleared by the Government of India.
Australia has recently on 19 October, released herbicide tolerant GM Indian mustard to meet the increasing global demand of edible oil.
(Source: National Academy of Agricultural Sciences and Trust for Advancement of Agricultural Science)