GM COTTON

Description

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Content

The Genetic Engineering Appraisal Committee (GEAC) has approved confined field trials for Pink Bollworm-resistant GM cotton in Hisar, Haryana.

What are GM Crops?

GM food involves the editing of genes of a crop in such a way that it incorporates beneficial traits from another crop or organism.
This could mean changing the way the plant grows, or making it resistant to a particular disease.
Food produced using the edited crop is called GM food. This is done using the tools of genetic engineering.

Bt Cotton

Bt cotton is a genetically modified pest resistant plant cotton variety, which produce an insecticide to combat bollworm.

Description

Strains of the bacterium Bacillus thuringiensis produce over 200 different Bt toxins, each harmful to different insects.
Most notably, Bt toxins are insecticidal to the larvae of moths and butterflies, beetles, cotton bollworms and flies but are harmless to other forms of life.
The gene coding for Cry group of endotoxin has been inserted into cotton as a transgene, causing it to produce this natural insecticide in its tissues.

Bt Cotton in India

The GEAC had approved the use of the BT cotton, a genetically modified variety of cotton, in 2002 to combat this pest. It was introduced to India to reduce farmers’ insecticide use.
Research by University of Manchester shows that the effects of Bt cotton on farmers’ yield vary across Indian states, but most states show a decrease in insecticide use since the introduction of Bt cotton. A reduction in insecticide use may be beneficial for farmers’ health and the environmentby reducing pollutants.

Concerns raised

By 2009, the Pink Bollworm had started to develop a resistance to the protein, necessitating further study into GM cotton.
Bt cotton has little effect on cotton yield, and although it may have led to an initial reduction in insecticide use, this effect is now diminishing due to insecticide-resistance in insect populations.
Also, Bt cotton is ineffective against many cotton pests such as plant bugs, stink bugs, and aphids.

The recent nod to Pink Bollworm-Resistant GM Cotton trials

The new variety's Cry2ai gene, which confers pest resistance on the cotton and is also derived from the bacterium Bacillus Thuringiensis.
The two genes and the proteins they generate do, however, differ from one another. While Cry2Ai targets a wider variety of insects, including some coleopteran (beetle) and dipteran (fly) species, Cry1Ac primarily targets lepidopteran insects (moths and butterflies).

Significance

Pink Ballworm is a significant issue for the cotton industry in India and is regarded as one of the most destructive pests of cotton globally.
The cotton yield and quality are decreased as a result of the Pink Bollworm larvae feeding on the seeds and fibres found inside cotton bolls.
Approval for trials from the GEAC, could be a significant step towards combating this destructive pest.

PRACTICE QUESTION

Q) Resistance to insecticides and to Bt toxins in pink bollworm are running havoc on Indian cotton industry. Comment.