Question

Give an account of mutation breeding with examples.

Answer 1

The mutation is a sudden heritable change in the genotype. In mutation breeding, desirable mutations are induced in crop plants with the use of physical or chemical mutagens.

1. Natural (physical) mutagens are High temperature, high concentration of CO2, X rays, UV rays.
2. Chemical mutagens are Nitrous acid, EMS (Ethyl- Methyl- Sulphonate), Mustard gas, Colchicine, etc.
3. Seedlings or seeds are irradiated by CO-60, exposed to UV bulbs, X-ray machines, etc.
4. Mutagens cause gene mutations and chromosomal aberrations.
5. The treated seedlings are then screened for resistance to diseases/ pests, high yield, etc. e.g. Jagannath variety of rice, NP 836 variety of wheat (rust-resistant), Indore-2 variety of cotton (resistant to bollworm), Regina-II variety of cabbage (resistant to bacterial rot), etc.