2.3. Induced Mutations
Agents that are used to induce hereditary changes are broadly divided into physical and chemical mutagens. Crops are induced to mutate through the exposure of their propagules to physical and chemical mutagenic agents. For seed propagated crops, botanical seeds are treated with the mutagens while for vegetatively propagated plants, other plant parts used for propagation such as stem cuttings, twigs, buds and tubers are exposed to the mutagenic agent. More recently, the induction of mutations in vegetatively propagated plants is becoming more efficient as scientists take advantage of totipotency, i.e., the inherent ability of individual plant cells to regenerate into whole plants, to use single cells and other forms of in vitro cultured plant tissues as starting materials for the induction of mutations.