Editorial Analysis – Understanding GM mustard: what is it, and how has it been achieved?

GS Paper 3

Science & Technology: Awareness in the fields of Biotechnology

Genetic Engineering Appraisal Committee (GEAC) under the Union Ministry of Environment, Forest and Climate Change recommended the “environmental release” of the transgenic hybrid mustard DMH-11 for seed production and conduct of field demonstration studies with respect to its effects, if any, on honey bees and other pollinating insects.

What exactly is hybrid mustard?

• Hybridisation involves crossing two genetically dissimilar plant varieties that can even be from the same species.
• The first-generation (F1) offspring from such crosses tend to have higher yields than what either parent can individually give.
• Hybridisation isn’t easy in mustard, as its flowers have both female (pistil) and male (stamen) reproductive organs, making the plants largely self-pollinating.
• Eggs of one plant cannot be fertilised by the pollen grains from another, it limits the scope for developing hybrids.
• Cotton, maize or tomato, where this can be done through simple emasculation or physical removal of anthers.

How has hybridisation been achieved in mustard?

By genetic modification (GM). Scientists at Delhi University’s Centre for Genetic Manipulation of Crop Plants (CGMCP) have developed the hybrid mustard DMH-11 containing two alien genes isolated from a soil bacterium called Bacillus amyloliquefaciens.

• DMH – 11 was created through transgenic technology, primarily involving the Bar, Barnase and Barstar gene systems.
• DMH – 11 was created through transgenic technology, primarily involving the Bar, Barnase and Barstar gene systems.
• Claimed to have shown an average 28% yield increase over Varuna in contained field trials carried out by the Indian Council of Agricultural Research (ICAR).

What has GEAC now done?

GEAC is a body responsible for appraisal of proposals relating to the “release” of GM organisms and products (ordinarily considered hazardous) into the environment.

• GEAC has also recommended the environmental release of DMH-11’s parental lines (carrying the barnase and barstar genes) for them to be used to develop new hybrids. Such hybrids could give even higher yields than DHM-11.
• Mustard varieties in India have a narrow genetic base. The barnase-barstar system enables breeding of hybrids from a wider range of mustards, including those of East European origin such as ‘Heera’ and ‘Donskaja’.

Why did it take so long for GEAC to clear?

In GM mustard, there have been two specific concerns voiced as well.

• Presence of a third ‘bar’ gene, which makes GM mustard plants tolerant to the spraying of glufosinate ammonium, a chemical used for killing weeds.
  • Will cause displacement of manual labour engaged in weeding by promoting use of chemical herbicides.
• GM mustard threatening or undermining the population of honey bees.
  • Mustard flowers are a source of nectar for honey bees and many other pollinator insects.

Source – Indian Express