Plant Breeding for Water-Limited Environments

TABLE OF CONTENTS Preface 1. The Moisture Environment 1.1. The Palmer drought index 1.2. The crop moisture index 1.3. The conventions of crop water use 2. Plant Water Relations, Plant Stress and Plant Production 2.1. The initiation of plant water deficit 2.2. The soil-plant-atmosphere continuum (SPAC) 2.2.1. The albedo 2.2.2. The water flux 2.2.3. Root resistance 2.2.4. Stem resistance 2.2.5. Leaf resistance (excluding stomata and cuticle) 2.2.6. Stomatal resistance 2.2.7. Cuticular resistance 2.3. Plant size and the development of water deficit 2.4. Plant water status and plant stress 2.4.1. Osmotic adjustment (OA) 2.4.2. Abscisic acid (ABA) 2.5. Growth and water deficit 2.6. Root growth under drought stress 2.7. The formation of yield and drought stress 3. Drought Resistance and its Improvement 3.1. Genetic gains achieved in plant breeding for drought resistance 3.2. Genomics and breeding for drought resistance 3.2.1. Gene expression and gene discovery 3.2.2. Marker-assisted selection (MAS) for drought resistance 3.2.3. Transgenic plants 3.3. Drought resistance in terms of yield 3.3.1. Drought resistance and yield potential: the crossover interaction 3.3.2. The heritability of yield and drought stress 3.3.3. QTLs and yield under drought stress 3.4. Drought resistance in terms of physiology 3.4.1. The disease resistance analogy 3.4.2. The components of drought resistance 3.5. Water-use efficiency (WUE) 3.5.1. Effective use of water (EUW) and not WUE is the important driver of yield under drought stress 3.6. Summary of plant constitutive traits controlling drought resistance 3.7. The drought resistant ideotype 3.7.1. The ideotype with respect to drought stress scenarios 3.7.2. The ideotype with respect to timing of stress 4. Phenotyping and Selection 4.1. The managed stress environment 4.1.1. Site homogeneity 4.1.2. Experiment station faults 4.1.3. Controlling the water regime 4.1.4. Controlling the severity and timing of stress in the field 4.1.5. Managed drought in protected environments 4.2. Protocols for drought resistance 4.2.1. Plant growth and productivity 4.2.2. Plant water status – the expression of dehydration avoidance 4.2.3. Dehydration tolerance 4.3. High throughput commercial phenotyping service 5. Genetic Resources for Drought Resistance 5.1. Cultivated germplasm 5.2. Landraces 5.3. Wild species and crop plant progenitors 5.4. Drought resistant transgenic plants 5.5. Resurrection plants 6. Breeding Considerations and Strategies 7. Epilogue