Induced Mutagenesis in Plants Using Physical and Chemical Agents

Abstract

Mutation, the heritable change to the genetic make up of an individual, occurs naturally and has been the single most important factor in evolution as the changes that are passed on to offspring lead to the development of new individuals, species and genera. The first reported cases of artificial induction of mutations, that is, the creation of genomic lesions above the threshold observable in wild types, were in the 1920s with work on Drosophila, maize and barley. Since these pioneering activities, induced mutagenesis has become widespread in the biological sciences, primarily for broadening the genetic base of germplasm for plant breeding and, more recently, as a tool for functional genomics. Mutations are induced in plants by exposure of their propagules, such as seeds and meristematic cells, tissues and organs, to both physical and chemical agents with mutagenic properties [1]. In some instances, whole plants are also exposed. Physical mutagens are mostly electromagnetic radiation such as gamma rays, X-rays, UV light and particle radiation, including fast and thermal neutrons, beta and alpha particles. Chemical mutagens include alkylating agents (such as the commonly used ethyl methane sulfonate – EMS), intercalating agents (such as ethidium bromide)