This book, Plant Breeding, has it bases in an earlier text entitled An Introduction to Plant Breeding by Jack Brown and Peter Caligari, first published in 2008. The challenges facing today's plant breeders have never been more overwhelming, yet the prospects to contribute significantly to global food security and farmers' quality of life have never been more exciting and fulfilling. Despite this there has been a worrying decline in public funding for plant breeding-related research and support for international centers of germplasm development and crop improvement. In part, this has resulted in a serious reduction in the number of young people interested in devoting their professional careers to plant breeding as well as the number of universities offering plant breeding courses or conducting relevant research in plant breeding. The authors' aim in writing this book is to provide an integrated and updated view of the current scientific progress related to diverse plant breeding disciplines, within the context of applied breeding programs. This excellent new book will encourage a new generation of students to pursue careers related to plant breeding and will assist a wider audience of agricultural students, agronomists, policy makers and those with an interest in agriculture in gaining insight about the issues affecting plant breeding and its key role in improving the quality of life of people and in securing sufficient food, at the quality required and at an affordable price. With comprehensive coverage including questions designed for students, and an accompanying website containing additional material to help in the study of the subject, Plant Breeding is an ideal text for all those studying plant and crop sciences, and a convenient reference source for professionals working in the area. All libraries within universities and research establishments where biological and agricultural sciences are studied and taught should have multiple copies of this book.

InhaltsangabePreface xi About the companion website xiii 1 Introduction 1 1.1 Requirements of plant breeders 1 1.2 Evolution of crop species 4 1.2.1 Why did hunter-gatherers become farmers? 4 1.2.2 What crops were involved? And when did they arise? 5 1.3 Natural and human selection 8 1.4 Contribution of modern plant breeders 8 Think questions 11 2 Modes of Reproduction and Types of Cultivar 13 2.1 Introduction 13 2.2 Modes of reproduction 15 2.2.1 Sexual reproduction 15 2.2.2 Asexual reproduction 16 2.3 Types of cultivar 17 2.3.1 Pureline cultivars 17 2.3.2 Openpollinated cultivars 17 2.3.3 Hybrid cultivars 18 2.3.4 Clonal cultivars 18 2.3.5 Synthetic cultivars 18 2.3.6 Multiline cultivars 18 2.3.7 Composite-cross cultivars 19 2.4 Annuals and perennials 19 2.5 Reproductive sterility 19 Think questions 19 3 Breeding Objectives 21 3.1 Introduction 21 3.2 People, politics and economic criteria 22 3.3 Grower profitability 25 3.3.1 Increasing harvestable yield 26 3.3.2 Selection for yield increase 27 3.4 Increasing end-use quality 28 3.4.1 Testing for end-use quality 30 3.5 Increasing pest and disease resistance 31 3.6 Types of plant resistance 34 3.7 Mechanisms for disease resistance 35 3.8 Testing plant resistance 36 3.9 Conclusions 38 Think questions 38 4 Breeding Schemes 40 4.1 Introduction 40 4.2 Development of pure-line cultivars 40 4.2.1 Homozygosity 41 4.2.2 Breeding schemes for pure-line cultivars 43 4.2.3 Number of segregating families and selections 46 4.2.4 Seed increases for cultivar release 46 4.3 Developing multiline cultivars 47 4.3.1 Backcrossing 48 4.4 Development of open-pollinated population cultivars 49 4.4.1 Breeding schemes for open-pollinating population cultivars 49 4.4.2 Backcrossing in open-pollinated population cultivar development 51 4.5 Developing synthetic cultivars 51 4.5.1 Seed production of a synthetic cultivar 53 4.6 Developing hybrid cultivars 53 4.6.1 Heterosis 55 4.6.2 Types of hybrid 58 4.6.3 Breeding system for F1 hybrid cultivars 58 4.6.4 Backcrossing in hybrid cultivar development 59 4.6.5 Hybrid seed production and cultivar release 60 4.7 Development of clonal cultivars 61 4.7.1 Outline of a potato breeding scheme 61 4.7.2 Time to develop clonal cultivars 62 4.7.3 Sexual reproduction in clonal crops 63 4.7.4 Maintaining disease-free parental lines and breeding selections 64 4.7.5 Seed increase of clonal cultivars 64 4.8 Developing apomictic cultivars 64 4.9 Summary 65 Think questions 65 5 Genetics and Plant Breeding 68 5.1 Introduction 68 5.2 Qualitative genetics 68 5.2.1 Genotype/phenotype relationships 70 5.2.2 Segregation of qualitative genes in diploid species 70 5.2.3 Qualitative loci linkage 72 5.2.4 Pleiotropy 76 5.2.5 Epistasis 76 5.2.6 Qualitative inheritance in tetraploid species 77 5.2.7 The chi-square test 79 5.2.8 Family size necessary in qualitative genetic studies 81 5.3 Quantitative genetics 82 5.3.1 The basis of continuous variation 82 5.3.2 Describing continuous variation 83 5.3.3 Relating quantitative genetics and the normal distribution 86 5.3.4 Quantitative genetics models 87 5.3.5 Testing the models 90 5.3.6 Quantitative trait loci 97 Think questions 101 6 Predictions 104 6.1 Introduction 104 6.1.1 Genotype × environment interactions 104 6.1.2 Genetically based predictions 105 6.2 Heritability 106 6.2.1 Broadsense heritability 107 6.2.2 Narrowsense heritability 108 6.2.3 Heritability from offspring - parent regression 109 6.3 Diallel crossing designs 110 6.3.1 Griffing's analysis 111 6.3.2 Hayman and Jinks' analysis 116 6.4 Cross prediction 119 Think questions 120 7 Selection 125 7.1 Introduction 125 7.2 What to select and when to select 125 7.2.1 Qualitative trait selec

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