Plant Breeding for Water-Limited Environments

This volume will be the only existing single-authored book offering a science-based breeder’s manual directed at breeding for water-limited environments. Plant breeding is characterized by the need to integrate information from diverse disciplines towards the development and delivery of a product defines as a new cultivar. Conventional breeding draws information from disciplines such as genetics, plant physiology, plant pathology, entomology, food technology and statistics. Plant breeding for water-limited environments and the development of drought resistant crop cultivars is considered as one of the more difficult areas in plant breeding while at the same time it is becoming a very pressing issue. This volume is unique and timely in that it develops realistic solutions and protocols towards the breeding of drought resistant cultivars by integrating knowledge from environmental science, plant physiology, genetics and molecular biology.

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

Abraham Blum is senior scientist retired from The Volcani Center, Agriculture Research Organization, at Bet Dagan, Israel where he headed the dryland wheat and sorghum breeding programs. Throughout his career his main interest was in understanding how plants cope with drought and heat stress and subsequently identify principles and develop methods for the genetic improvement of plant production under drought and heat stress. He authored numerous scientific papers and reviews on the subject as well as a book entitled ‘Plant Breeding for Stress Environments’. Presently he is consulting and teaching, while curating his web site at www.plantstress.com.