1. Mutations denote sudden heritable changes in the genetic makeup.
2. The occurrence of natural mutations is characterized by a slow rate of occurrence.
3. Natural physical mutagens encompass factors like exposure to elevated temperatures, high concentrations of CO2, X-rays, and UV rays.
4. Induction of mutations can be achieved through the use of various mutagens.
5. Mutagens have the potential to instigate gene mutations and chromosomal aberrations.
6. Chemical mutagens, including nitrous acid, EMS (Ethyl – Methyl – Sulphonate), mustard gas, colchicine, among others, contribute to induced mutations.
7. Seedlings or seeds undergo irradiation using CO60, UV bulbs, or X-ray machines.
8. Following irradiation, mutated seedlings are screened to identify desirable traits such as disease or pest resistance and high yield.
9. Illustrative instances of mutant varieties in different crops include Jagannath (rice), NP 836 (rust-resistant wheat), Indore-2 (cotton variety resistant to bollworm), and Regina-II (cabbage variety resistant to bacterial rot).