Genetic Engineering Appraisal Committee approves commercial cultivation of genetically modified mustard yet again

Source: The post is based on the following articles

“Years after Bt cotton, GEAC clears environmental release of GM mustard” published in Business Standard on 26th October 2022

“Understanding GM mustard: what is it, and how has it been achieved?” published in Indian Express on 27th October 2022

“Genetic Engineering Appraisal Committee approves commercial cultivation of genetically modified mustard yet again” published in The Hindu on 27th October 2022

What is the News?

The Genetic Engineering Appraisal Committee(GEAC) has recommended the environmental release of the Genetically Modified(GM) mustard variety DMH (Dhara Mustard Hybrid)-11, paving the way for the commercialisation of the country’s first GM food crop.

What 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.

Such hybridisation isn’t easy in mustard as its flowers have both female (pistil) and male (stamen) reproductive organs making the plants largely self-pollinating. 

Since the eggs of one plant cannot be fertilized by the pollen grains from another, it limits the scope for developing hybrids — unlike in cotton, maize or tomato where this can be done through simple emasculation or physical removal of anthers.

How was the GM Mustard produced then?

GM mustard was developed by the Centre for Genetic Manipulation of Crop Plants (CGMCP) at Delhi University by genetic modification (GM)

The scientists have deployed the barnase-barstar GM technology to develop DMH-11, containing two alien genes isolated from a soil bacterium called Bacillus amyloliquefaciens.

The barnase gene codes for a protein that impairs pollen production and renders the plant into which it is incorporated male-sterile.

This plant is then crossed with a fertile parental line containing the barstar gene that blocks the action of the barnase gene.

The resultant F1 progeny is both high-yielding and also capable of producing seed/ grain.

Note: DMH-11 was developed by crossing the Indian mustard variety ‘Varuna’ (barnase line) with an East European ‘Early Heera-2’ mutant (barstar).

Why did it take so long for GEAC to clear GM Mustard?

There has been opposition to GM crops in general from several groups. In GM mustard, there have been two specific concerns voiced as well:

The first concern is the presence of a third ‘bar’ gene, which makes GM mustard plants tolerant to the spraying of glufosinate ammonium, a chemical used for killing weeds. Some allege that this will cause displacement of manual labour engaged in weeding by promoting the use of chemical herbicides.

The second concern is over 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.