Question
Give an account of mutation breeding with examples.
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Answer
- Mutations are sudden heritable changes in the genotype.
- Natural mutations occur at a very slow rate.
- Natural physical mutagens include exposure to high temperature, high concentration of C02, X-rays, UV rays.
- Mutations can be induced by using various mutagens.
- Mutagens cause gene mutations and chromosomal aberrations.
- Chemical mutagens include nitrous acid, EMS (Ethyl – Methyl – Sulphonate), mustard gas, colchicine, etc.
- Seedlings or seeds are irradiated by using CO60 or UV bulbs or X-ray machines.
- The mutated seedlings are then screened for resistance to diseases/pests, high yield, etc.
- Examples of mutant varieties in different crops are Jagannath (rice), NP 836 (rust resistant wheat variety), Indore-2 (cotton variety resistant to bollworm), Regina-II (cabbage variety resistant to bacterial rot).
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