Application of mutation in crop improvement

Abstract

Genetic variation is a source of phenotypic diversity and is a major driver of evolutionary diversification. Heritable variation was observed and used thousands of years ago in the domestication of plants and animals. The mechanisms that govern the inheritance of traits were later described by Mendel. Plant breeding requires genetic variation of useful traits for crop improvement. The induction of mutations has been used to enhance the yield, better nutritional quality and wider adaptability of world's most important crops such as wheat, rice, pulses, millets and oilseeds. The total area covered by commercially released mutant cultivars clearly indicates that they have played a significant role in solving food and nutritional security problems in many countries. Of all the mutant varieties developed, majority of mutants were produced through direct mutagenesis of the plant propagules and also there are several reports of mutants derived by irradiating rooted stem cuttings, which paves the way for in vitro mutagenesis. The incorporation of desired traits from non-adapted landraces or crop wild resources can speed up crop improvement. Among the different strategies to enhance crop improvement programs, induced mutagenesis has contributed immensely by creating mutant varieties with improved and desirable genetic changes in agronomic ally important traits of the crop plants. Such genetic changes can occur spontaneously naturally at a very low rate or experimentally induced by physical and chemical mutagens. Conventional mutation techniques have often been used to improve yield, quality, and disease and pest resistance in crops or to increase the attractiveness of flowers and ornamental plants. In general, mutation is the main source of genetic variation, which is the raw material for evolution by natural selection. Recognize that mutations are the basis of microevolution and that adaptations enhance the survival and reproduction of individuals in a population. Mutation breeding has greater impact in sustainable crop production by developing new mutant varieties. With the advances in genomics research and availability of genome sequences, induced mutants continue to be a genetic resource for elucidating genetic mechanisms and metabolic pathways. Agricultural sustainability and food security are major challenges facing continued population growth. Integration of existing and new technologies for the induction and exploitation of genetic diversity towards developing healthier, nutritious and productive crops is the need of the hour. Mutagenesis is a proven technology for the development of improved or novel varieties with desirable traits. Several mutant genes have been successfully explored, either directly or indirectly, to complement crop productivity.