Question

Bt brinjal was developed for resistance to

• A. Salinity
• B. Fruit and shoot borer
• C. Damping off disease
• D. Drought

Hint:

While Bt cotton is widely grown in India, Bt brinjal faced a moratorium in 2010. It is, however, commercially cultivated in Bangladesh.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Bt crops are genetically modified organisms (GMOs) that express an insecticidal protein derived from the soil bacterium Bacillus thuringiensis. These proteins (Cry toxins) are highly specific to certain orders of insects.

Step 2: Detailed Explanation:
Brinjal (Eggplant) is severely affected by the Fruit and Shoot Borer (Leucinodes orbonalis), a lepidopteran pest. Farmers often use excessive amounts of chemical pesticides to control this pest, which leads to health and environmental concerns.
Bt brinjal was developed by Mahyco in collaboration with public institutions (like TNAU and UAS Dharwad) by inserting the {cry1Ac gene. This gene produces a protoxin that, when ingested by the borer larvae, is activated in their alkaline gut, leading to pore formation in the gut lining and the death of the insect. This provides built-in resistance specifically against the borer larvae, significantly reducing the need for external pesticide sprays.
- Option 1 and 4 (Salinity/Drought) require abiotic stress tolerance genes.
- Option 3 (Damping off) is a fungal disease caused by Pythium or Phytophthora, which Bt toxins do not affect.

Step 3: Final Answer:
Bt brinjal specifically targets the lepidopteran pest Leucinodes orbonalis (Fruit and shoot borer). Option 2 is correct.