History of Plant Mutation Breeding and Global Impact of Mutant Varieties

Abstract

Hugo de Vries coined the term ‘Mutation’ in his classical hypothesis known as ‘Mutationtheorie’. Immediately after the discovery of mutagenic effects of X-rays on Drosophila by Muller and barley, maize by Stadler, about nine decades ago extensive experiments on induced mutations were initiated. In the three decades that followed the pioneering work of Muller and Stadler to understand the nature of mutations, induction techniques and their role in evolution, genetics and plant breeding, a great deal of work on basic aspects of induced mutation technique in understanding the mechanism of gene mutations, mode of action of physical and chemical mutagens was done world over. Several countries took up the task of crop improvement through the use of mutation technique in their classical breeding programmes as well as through molecular approaches. During 1950–1960, several countries took up the task of crop improvement through mutation breeding approaches, particularly after the establishment of the International Atomic Energy Agency (IAEA) which started coordinated programmes on the use of mutation breeding technique in a large number of crops in several countries of the world. Over 3500 mutant varieties belonging to >240 plant species including cereals, pulses, oilseeds, vegetables, fruits, fibres and ornamentals that have been developed and released by 2022 are evidence of the successful use of mutation technique in plant breeding. A wide range of characters including yield, flowering and maturity duration, plant architecture, quality and tolerance to biotic and abiotic stresses have been improved in the mutant varieties developed so far. As per the IAEA records, majority of these mutant varieties were developed and released as direct mutants, the rest were released through cross-breeding with mutants. Most of the mutant varieties have been developed using physical mutagens, with gamma rays alone accounting for the development of majority of the mutant varieties. Since induced mutagenesis is gaining importance in plant molecular biology as a tool to identify and isolate genes and to study their structure and function, interest in mutation techniques and mutation breeding has increased recently in several area of biological research. These studies have an enormous potential for future crop improvement programmes. To redesign our crops by placing important traits on genetic maps and to equip them with the genes and attributes that could meet the huge food production challenges, there is an urgent need to use a combination of molecular and induced mutation techniques. Large-scale use of mutation breeding methods have made a significant contribution to the national economies of several countries.