India to Begin Large-Scale Cultivation of IMI-Resistant Mustard Hybrids

India is set to launch large-scale cultivation of Imidazolinone-resistant (IMI-resistant) mustard hybrid varieties during the 2026-27 Rabi sowing season.

IMI-Resistant Mustard Hybrids – Mustard varieties that are resistant to Imidazolinone herbicides (weed killers).

These have been developed to tackle the problem of *Orobanche*, a parasitic weed that poses a major obstacle to oilseed production.

Mustard is a key oilseed crop. In 2024-25, India imported approximately 16 million tonnes of edible oil, valued at around ₹1.6 lakh crore.

IMI-Resistant Mustard

It was developed using a process known as mutation breeding, wherein scientists breed crops to retain specific natural mutations.

This process targets the enzyme acetolactate synthase (ALS), which is essential for plant growth.

IMI herbicides inhibit the ALS enzyme, thereby hindering growth and causing the plant to die.

In IMI-resistant hybrids, a mutation alters the ALS enzyme, preventing the herbicide from binding to it.

Development of IMI-Resistant (Imidazolinone-Resistant) Mustard

The IMI-resistant mustard hybrid varieties were developed by Dr. Deepak Pental and his team of scientists at the 'Centre for Genetic Manipulation of Crop Plants' (CGMCP) at the University of Delhi. These hybrid varieties were developed using 'mutation breeding' technology to intentionally induce genetic changes in the 'acetolactate synthase' (ALS) enzyme.

This modification allows the mustard plants to survive even when IMI herbicides (weed killers) are applied.

Benefits of IMI-resistant mustard hybrid varieties

Orobanche is a parasitic weed that attaches to mustard roots and extracts water and nutrients from the host plant.

Weed management: Enables effective control of Orobanche/Phelipanche.

Reduced labor dependence: Minimizes the need for labor-intensive manual weeding.

Difference between hybrid and genetically modified (GM) crops

Hybrids: Developed through the cross-breeding of genetically distinct parent plants to combine desirable traits.

GM crops: Developed using genetic engineering techniques to directly insert or modify genes; examples include Bt cotton (gene derived from *Bacillus thuringiensis*) and GM mustard.