Question

Which among the following is generally used as induced mutagens in crop plants?

• A. $\alpha$-particles
• B. X rays
• C. UV (260 nm)
• D. $\gamma$-rays (from cobalt 60)

Answer 1

Answer: (D)

$\gamma$-rays (from cobalt 60)

The wave length and penetrance of radiations are inversely proportional. Radiations with lower wave length have higher penetrance and provide the source of acute radiation dose which is quickly supplied to target cell. X rays have higher penetrance but serve as source of acute radiations, hence are not used for crop plants but to seeds. $\alpha$-radiation, also provide intense radiations but energy deposition is superficial and localized; thus are not used for crop plants. $\gamma$-rays are ionizing radiations which serve as chronic source of radiations which traverse deep in tissues and hence is used for crop plants. UV rays are non-ionizing radiations that have low penetrance and thus cannot be used for multilayered, multicellular crop plants but are used for single celled prokaryotes and single layered pollens.