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

Jack Brown, Full Professor, Plant Breeding & Genetics, University of Idaho, USA. HNC Mathematics & Statistics, Napier College, Edinburgh, Scotland; MSc and PhD at St Andrews University, St Andrews, Scotland. Professor Brown has over 40 years of experience working as a plant breeder in the public and private sector and has developed and released cultivars of barley, potato, canola, mustard and wheat. Professor Brown currently teaches upper division and graduate classes in plant breeding, genetics, and field crop production. Peter Caligari, Full Professor, University of Talca, Chile. BSc, PhD and DSc at University of Birmingham, UK. Professor Caligari has over 40 years of research experience in, and application of, genetics and plant breeding in a range of crops including potatoes, cashew nuts, oil palm, lupins, strawberries and blueberries, and extensive teaching experience including plant breeding and genetics at the graduate and post-graduate level. Hugo Campos, Fellow, Monsanto, Chile. BSc at Universidad Austral de Chile, PhD at the John Innes Centre, UK, MBA at Universidad del Desarrollo, Chile. Dr Campos has over 24 years of experience in plant biotechnology, crop breeding and product development in industry, academia and international agricultural development.

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