Agricultural plant genetic resources are constantly going into extinction having negative implications for plant genetic banks. Hence, there is a need to generate variations. Stimulated mutagenesis offers an efficient tool to generate genetic variation and explore the function of genes. It also facilitates the identification of genes and their roles in traits of economic interest to breeders, farmers and consumers. Thus, transforming the Argo-based industries in overcoming obstacles (poor yield, lodging, shattering, pests and disease infestations). Exploring alternatives to integrate farmers’ and consumers’ desirable traits into their preferred cultivars has led to major advancements in mutation breeding. The chapter provides a comprehensive update on induced mutagenesis approaches, increasing efficiency of targeted mutagenesis and identification of novel traits in mutated populations. Furthermore, it reveals the efforts of ten countries that are leading the development of varieties via mutation across the globe and the most prioritized crops that have received critical attention in mutation breeding. Moreover, it seeks to bring to light the current approaches used in facilitating mutation breeding. It details the current progress made in improving plants with evidence relating to generating genetic resources, biotic and abiotic stresses, nutritional, and quality improvement whiles providing future directions for mutation breeding. Induced mutations are considered as an alternative to naturally occurring variation as the source of germ plasm for plant improvement programs, and as an alternative to hybridization and recombination in plant breeding. There is no theoretical need to preserve naturally occurring variation as a source of germ plasm for traits controlled by single genes, but it is often more economical to transfer available genes than to induce new mutations. Until there is better understanding of the role of linked complexes of genes in determining quantitatively inherited traits, it will not be possible to fully delineate the relative roles of induced mutations and recombination for these traits. The relative advantages of mutation and recombination in plant breeding have been considered in relation to the genetic nature of the trait to be improved and the breeding system of the species. The cost of mutation plant breeding has been assessed in terms of the effort required (population sizes) and the effect on the background genotype. New concepts which suggest that mutations are neither rare events nor largely deleterious in their effects have been reviewed. The relevance of these concepts to some aspects of the use of induced mutations in plant improvement have been considered. Some recent attempts to increase the genetic specificity of mutations have been reviewed.
Crop breeding’s objectives in earlier decades included enhanced potential yield, increased and altered oil and protein content, and tolerance to biotic and abiotic stresses. In traditional breeding, we selected plants with desirable traits and culled those with fewer desirable traits. Another technique, known as cross-breeding, involves mating sexually healthy parental lines, whether they are closely or distantly related, to create new lines that have new forms with desirable traits. On the other hand, encouraging plant mutation will quicken the reproduction process. Mutation breeding techniques can induce site-specific mutations while this is difficult to achieve by conventional breeding techniques. Micki and Donini pointed that breeders are dealing only a few hundred out of 100,000 genes, when two established cultivars are crossed while mutation is induced, may affect any of the 100,000 genes of a nuclear genome. Mutations are the primary source of all genetic variations existing in any organism, including plants. Consequently, the likelihood of finding a novel gene will rise. Understanding mutations and utilizing them has made it possible to increase plant biodiversity and genetic resources for increasing food production in order to counteract climatic changes. Additionally, induced mutagenesis is a safe, effective, and successful method of plant breeding, and the crop varieties it creates considerably improve food security around the world while maximizing plant biodiversity, genetic resources, and the preservation of natural resources. More than 3200 mutant varieties of ornamentals, trees, and crops have been formally released to be used in more than 70 nations. The genetic diversity found within plants’ agricultural genetic resources helps to address a number of problems in plant breeding. Since mutations occur at such low frequencies, the discovery of advantageous mutations involves the establishment of very large mutant populations, which has long been a challenge. It is often called the real “art” of mutation breeding to differentiate and select among the a lot of mutated plants those tenuous cases that have developed new desirable traits as generated bythe mutation. Recent improvements in mutation detection technologies have increased the accuracy of identifying DNA mutations that cause a novel characteristic. Molecular markers, such TILLING (targeted induced local lesions in the genome), which allows for the direct determination of mutations in a specific gene, assisted breeders in accelerating the process of combining the desirable traits into an employed variety. At the same time, there are some restrictions on the application mutation breeding such as most of the mutations are lethal, rate is very low, screening is a quite laborious, mostly reversible, mutations mostly are recessive, and the mutations must be induced in gametes to appear. In the coming decades, though, mutations will continue to occupy a place in crop research, particularly for the intensification of crop production to mitigate climate change.
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