Somaclonal Variation and Induced Mutations in Crop Improvement (Current Plant Science and Biotechnology in Agriculture, 32)

Genetic variability is an important parameter for plant breeders in any con­ ventional crop improvement programme. Very often the desired variation is un­ available in the right combination, or simply does not exist at all. However, plant breeders have successfully recombined the desired genes from cultivated crop gerrnplasm and related wild species by sexual hybridization, and have been able to develop new cultivars with desirable agronomie traits, such as high yield, disease, pest, and drought resistance. So far, conventional breeding methods have managed to feed the world's ever-growing population. Continued population growth, no further scope of expanding arable land, soil degradation, environ­ mental pollution and global warrning are causes of concern to plant biologists and planners. Plant breeders are under continuous pressure to improve and develop new cultivars for sustainable food production. However, it takes several years to develop a new cultivar. Therefore, they have to look for new technologies, which could be combined with conventional methods to create more genetic variability, and reduce the time in developing new cultivars, with early-maturity, and improved yield. The first report on induced mutation of a gene by HJ. Muller in 1927 was a major mi1estone in enhancing variation, and also indicated the potential applica­ tions of mutagenesis in plant improvement. Radiation sources, such as X-rays, gamma rays and fast neutrons, and chemical mutagens (e. g. , ethyl methane sulphonate) have been widely used to induce mutations. Front Matter....Pages i-xiii Front Matter....Pages 1-1 Introduction....Pages 3-13 Somaclonal Variation: Mechanism and Applications in Crop Improvement....Pages 15-37 Clonal Variation in Cereals and Forage Grasses....Pages 39-64 Genetic Fidelity of Plants Regenerated from Somatic Embryos of Cereals....Pages 65-80 Somaclonal Variation in Improving Ornamental Plants....Pages 81-104 Somaclonal Genetics of Forest Trees....Pages 105-121 Gametoclonal Variation in Crop Plants....Pages 123-133 Protoclonal Variation in Crop Improvement....Pages 135-148 Chromosomal Basis of Somaclonal Variation in Plants....Pages 149-168 Somaclonal Variation and In-vitro Selection for Crop Improvement....Pages 169-201 Somaclonal Variation in Crop Improvement....Pages 203-218 Field Performance of Banana Micropropagules and Somaclones....Pages 219-231 Somaclonal Variation in Solanaceous Medicinal Plants....Pages 233-251 Front Matter....Pages 253-253 Induced Mutation in Plant Breeding: Current Status and Future Outlook....Pages 255-291 In-vitro Techniques and Mutagenesis for the Improvement of Vegetatively Propagated Plants....Pages 293-309 Mutation Breeding in Cereals and Legumes....Pages 311-332 Induced Mutations in Ornamental Plants....Pages 333-366 In-vitro -Induced Mutations for Disease Resistance....Pages 367-378 EMS and Transposon Mutagenesis for the Isolation of Apomictic Mutants in Plants....Pages 379-400 Induced Mutation in Fruit Trees....Pages 401-419 Front Matter....Pages 253-253 Induced Mutations and Somaclonal Variation in Sugarcane....Pages 421-446 Field Performance of Selected Sugarcane ( Saccharum spp. Hybrids) Mutants....Pages 447-462 Front Matter....Pages 463-463 Molecular Basis of Heritable Tissue Culture-induced Variation in Plants....Pages 465-484 Molecular and Biochemical Characterization of Somaclonal Variation....Pages 485-499 Recombinase-mediated Gene Integration in Plants....Pages 501-516 T-DNA Insertion Mutagenesis and the Untagged Mutants....Pages 517-538 Phenotypic Variation Between Transgenic Plants: What is Making Gene Expression Unpredictable?....Pages 539-562 Transposable Elements and Genetic Variation....Pages 563-594 Detection of Dwarf Somaclones of Banana Cultivars ( Musa ) by RAPD Markers....Pages 595-601 Back Matter....Pages 603-619

The basic purpose of this book is to describe the relative value of each method of improving various agricultural crops by using parasexual techniques. While no book can be a complete source of all the information on a subject, a range of topics were selected to highlight the recent developments in mutagenesis (conventional approach and molecular biology) and in vitro induced variation in plant breeding. We have deliberately kept short the title of this book, simply emphasizing somaclonal variation and induced mutation.
This book is divided into three sections. Section 1 contains 13 chapters mainly on somaclonal variation (SCV), covering SCV in crop improvement, SCV in ornamentals, cereals and forage grasses, banana, and forest trees, cytogenetic basis of SCV, in vitro selection, gamelonal variation, prolonal variation, and solanaceous medicinal plants. Section 2 deals with induced mutation, and is covered in 10 chapters mainly on mutagenesis in sugarcane, fruit trees, apomixsis, ornamental plants, disease resistance, cereals and legumes, and vegetatively propagated plants. Section 3 describes the molecular aspects of mutagenesis and somaclonal variation, insertional mutagenesis (T-DNA mutagenesis, transposons), and molecular methods for identifying somaclonal variation, RAPD markers in banana somaclones, and transgene expression.

The basic purpose of this book is to describe the relative value of each method of improving various agricultural crops by using parasexual techniques. While no book can be a complete source of all the information on a subject, a range of topics were selected to highlight the recent developments in mutagenesis (conventional approach and molecular biology) and in vitro induced variation in plant breeding. We have deliberately kept short the title of this book, simply emphasizing somaclonal variation and induced mutation. This book is divided into three sections. Section 1 contains 13 chapters mainly on somaclonal variation (SCV), covering SCV in crop improvement, SCV in ornamentals, cereals and forage grasses, banana, and forest trees, cytogenetic basis of SCV, in vitro selection, gametoclonal variation, protoclonal variation, and solanaceous medicinal plants. Section 2 deals with induced mutation, and is covered in 10 chapters mainly on mutagenesis in sugarcane, fruit trees, apomixsis, ornamental plants, disease resistance, cereals and legumes, and vegetatively propagated plants. Section 3 describes the molecular aspects of mutagenesis and somaclonal variation, insertional mutagenesis (T-DNA mutagenesis, transposons), and molecular methods for identifying somaclonal variation, RAPD markers in banana somaclones, and transgene expression