Showing papers on "Molecular breeding published in 1993"

Plant breeding: principles and prospects.

Abstract: Introduction. Genetic systems and population structure. Genetic systems, recombination and variability. Population structure and variability. Sources variation. Plant genetic resources. Induced mutations. Interspecific hybridization by sexual means. Chromosome manipulation and polyploidy. Somatic hybridization. Gene cloning and identification. Gene transfer to plants: approaches and available techniques. The role of gene technology in plant breeding. Assessment of variation. Biometrical genetics in breeding. Biochemical characterization of populations. Manipulation of genetic systems. Self- and cross-incompatibility systems. Male sterility. Apomixis. Micropropagation and somatic embryogenesis. Andro- and parthenogenesis. Selection methods. Selection strategies and choice of breeding methods. Marker-assisted selection. Gametophytic and sporophytic selection. In vitro selection. Adaptation. Genotype x environment interaction and adaptation. Augmenting yield-based selection. Resistance to abiotic stresses. Resistance to parasites. Specific trait breeding. Breeding for improved symbiotic nitrogen fixation. Photosynthetic and respiratory efficiency. Breeding for efficient root systems. On the utilization of renewable plant resources. Epilogue. The need for comprehensive plant breeding strategy.

Genetics and fish breeding

Abstract: Fish are a rich source of nutritious and delicious food to man. With the increasing demand for fish and fish products nearly every country with aquatic resources is making serious efforts to boost fish production. This is not surprising considering the fact that two-thirds of our planet is coverea with water and most of it supports fish life. Therefore the breeding of fish for food, for recreation and aesthetic needs, or in the context of conservation of natural species against environmental harm is of global importance. 'Genetic analysis of.fish species is an old practice. Yet, not many books are available, even for a basic course in fish genetics at the undergraduate level. Therefore, Genetics and Fish Breeding, by the well-known fish geneticist C. E. Purdom, is indeed a timely and much-needed publication. The book is an outcome of Purdom's lifetime work in fish genetics at the famous Lowestoft Fisheries Laboratory in the UK. In this compact book, he has neatly provided a precise and comprehensive account of the wide spectrum of research currently being carried out both for gaining an understanding of the principles of fish genetics and for their ultimate application(s) for higher productivity and disease resistance. The book is divided into 15 chapters. These chapters are written in a lucid and logical manner and can be followed even by beginners. Chapters 1 and 2 deal with the scope of applied fish genetics, and sexuality and reproduction, respectively. Chapters 3 and 4 describe the principles of genetics and Mendelian inheritance of colour and other characteristics in fish. Two chapters (chapters 5 and 6) have been devoted to quantitative genetics, including commercially important characters. In chapter 6 the author has included the use of molecular approaches to ascertain genetic relatedness within and between species. He has very briefly touched upon the use of DNA fingerigrinting (two paragraphs on pages 100 and 101), a technique that is now being used extensively not only for analysis of population structure, but also for behavioural, ecological, conservational and phylogenetic studies in a number of organisms, including fishes. Therefore, in my view, the statement 'In general, however, this wealth of information reflects the uniqueness of individuals and is of little help in population work, though it could be relevant in the study of highly inbred or clonal material' (pages 100, 101) is difficult to justify. I believe that a slightly more detailed coverage of this powerful technique, with special relevance to fish breeding and population studies, would have substantially added to the value of this otherwise thorough book. Chapter 7 gives a brief description of Cytogenetic studies in fishes, including methods for calculation of recombinational distance between genetic loci and the centromere by using the principle of gyriogenesis. Sex determination, hybridization, sexuality and control of sex ratios are included in chapters 8-11. In each of these chapters the author

The role of gene technology in plant breeding

Abstract: Plant breeders have made spectacular progress in the improvement of many crop species over the last 60 years. In wheat, rice and maize for example about 50% of the increase in the yield over the period 1930–1975 has been attributed to improved varieties; the remainder derives from greater and more efficient use of fertilizers and crop management. Recent advances in genetics, cell and molecular biology, particularly recombinant-DNA technology, provide new opportunities for manipulation of the genome to meet the varying demands of breeders.

Biotechnology and plant breeding

Abstract: Plant breeding is an integrative discipline that is defined by the product, i. e., a crop cultivar. Principles of breeding provide the framework, while technologies (including biotechnology) provide the tools for implementation. The successful execution of plant breeding depends on: availability of genetically variable populations, effective selection in such populations, and efficient testing of breeding lines. A measure of the contribution of biotechnology is to consider examples of its present and future impact on each of these steps in the breeding process.