Plant evolution and the origin of crop species,2nd ed

Preface ix Acknowledgements ix Introduction 1 Part 1. Evolutionary Processes 1. Chromosome Structure and Genetic Variability 3 Gene and Chromosomal Structure 4 Types of Mutation 5 Measurement of Variability 16 Construction of Genetic Maps and Genome Evolution 28 2. Assortment of Genetic Variability 32 Random Mating and Hardy–Weinberg Equilibrium 32 Migration 35 Selection 42 Genetic Drift 52 Evolution in Organelles 54 Interaction between Forces 55 3. The Multifactorial Genome 58 Intragenomic Interactions 60 Coadaptation 64 Canalization 72 Paradox of Coadaptation 73 4. Polyploidy and Gene Duplication 77 Factors Enhancing the Establishment of Polyploids 78 vEvolutionary Advantages of Polyploidy 80 Genetic Differentiation in Polyploids 93 Chromosomal Repatterning 95 Genome Amplification and Chance 98 5. Speciation 100 What is a Species? 100 Reproductive Isolating Barriers 103 Modes of Speciation 110 Genetic Differentiation during Speciation 117 Hybridization and Introgression 119 Hybridization and Extinction 124 Crop–Weed Hybridizations 125 Risk of Transgene Escape into the Environment 127 Part 2. Agricultural Origins and Crop Evolution 6. The Origins of Agriculture 129 Rise of our Food Crops 129 Emergence of Homo 131 Evolution of Homo 137 Appearance of Modern Humans 139 Spread of H. sapiens 141 Agricultural Origins 143 Early Crop Dispersals 145 Transcontinental Crop Distributions 148 7. The Dynamics of Plant Domestication 151 Evolution of Farming 153 Early Stages of Plant Domestication 154 Origins of Crops 157 Characteristics of Early Domesticants 159 Changes During the Domestication Process 161 Genetic Regulation of Domestication Syndromes 163 Evolution of Weeds 166 Genetic Diversity and Domestication 169 Domestication and Native Diversity Patterns 170 8. Cereal Grains 174 Barley 174 Maize 176 Millets 181 Oats 183 Rice 185 Rye 187 Sorghum 188 Wheat 1909. Protein Plants 195 Chickpea 195 Cowpea 196 Pea 198 Lentil 200 Phaseolus Beans 203 Faba Beans 206 Soybean 206 10. Starchy Staples and Sugars 209 Banana 209 Cassava 212 Potato 214 Sugar Cane 217 Sugar Beet 219 Sweet Potato 220 Taro 222 Yam 223 11. Fruits, Vegetables, Oils and Fibres 226 Fruits Apples 226 Citrus 228 Grape 230 Peach 231 Strawberry 232 Vegetables Cole Crops 234 Squash and Gourds 236 Chilli Peppers 238 Tomato 240 Fibres and Oils Cotton 241 Groundnut 243 Sunflower 244 12. Postscript: Germ-plasm Resources 246 Ex situ Conservation 248 In situ Conservation 249 References 251 Index 307