The Wheat Rusts - Breeding for Resistance

The idea for this book was conceived by the late Dr. Irvine A. Watson of the University of Sydney, and he developed the first outline. I was then invited by Dr. Watson to share in its writing. Unfortunately, shortly there­ after, recurring heart problems forced him to curtail his activities and with­ draw from the project. He died before the book could be completed. Dr. Watson's intention was to produce a very practical book that would provide wheat breeders with all of the information necessary to breed success­ fully for resistance to the three wheat rusts: leaf rust, stem rust, and yellow rust. It was intended to be very specific in describing procedures to be used and at the same time provide all of the necessary theoretical background. I hope that I have been successful in meeting these objectives. The book assumes that the reader has some knowledge of plant pathology, genetics, and plant breeding. Extensive use has been made of the literature, but it was not possible to cite all of the papers on a given topic. In making a choice, an attempt was made to choose key papers or more recent papers that provided references to the earlier literature. Acknowledgements This book was written partly at the University of Saskatchewan and partly at the University of California, Davis, while I was on a sabbatical leave.

Contenu

1 Introduction.- 1.1 The Hosts.- 1.2 The Pathogens.- 1.3 The Importance of the Rusts.- 1.4 Rust Control.- 1.5 Conclusion.- 2 The Wheat Rust Pathogens.- 2.1 Introduction.- 2.2 Life Cycles.- 2.3 Axenic Culture of the Rusts.- 2.4 Classifying Infection Types.- 2.5 Variability in the Rust Pathogens.- 2.6 The Origin of Pathogenic Variability.- 2.7 Eradicating Barberry to Control Stem Rust.- 3 Rust Tests Under Controlled Conditions.- 3.1 Introduction.- 3.2 Production and Storage of Inoculum.- 3.3 Seedling Rust Tests.- 3.4 Adult Plant Rust Tests.- 3.5 Tests with Accurate Control of Inoculation Rates.- 3.6 Field Rust Tests.- 4 Surveying Variability in Host and Pathogen.- 4.1 Race Surveys in the Rusts.- 4.2 Surveying Resistance in the Hosts.- 4.3 The Analysis of Rust Populations.- 5 Genetic Analysis of Resistance.- 5.1 Introduction.- 5.2 Early Genetic Studies on Resistance.- 5.3 Procedures for Determining the Inheritance of Resistance to Rust.- 5.4 The Inheritance of Resistance to Stem Rust.- 5.5 The Inheritance of Resistance to Leaf Rust.- 5.6 The Inheritance of Resistance to Yellow Rust (with R. Johnson).- 5.7 Identifying an Unknown Gene for Rust Resistance.- 5.8 Genetic Linkages.- 5.9 The Effect of Temperature on Genes for Resistance.- 5.10 The Inheritance of Complex Resistance.- 5.11 Procedures for Studying Complex Resistance.- 5.12 The Inheritance of Virulence in Rust Fungi.- 6 The Genetics of Host-Pathogen Interactions.- 6.1 Introduction.- 6.2 The Gene-for-Gene System.- 6.3 Using Infection Type Data Sets to Postulate Genotypes.- 6.4 Apparent Exceptions to the Gene-for-Gene Hypothesis.- 6.5 Race-Specific and Race-Non - Specific Resistance.- 6.6 Durable Resistance.- 6.7 Association and Dissociation of Genes for Virulence.- 7 Cytogenetic Analysis of Resistance.- 7.1 Development of Aneuploids.- 7.2 Maintaining Monosomics and Other Aneuploids.- 7.3 Producing Monosomic Series in Other Cultivars.- 7.4 Using Monosomics to Identify Chromosomes Carrying Genes for Rust Resistance.- 7.5 Chromosome Mapping Using Telocentrics.- 7.6 Production and Use of Substitution Lines.- 7.7 The Use of Reciprocal Monosomic Hybrids.- 7.8 The Backcross Reciprocal Monosomic Method.- 7.9 Monosomic Analysis in Durum Wheat.- 8 Breeding Methods.- 8.1 Introduction.- 8.2 Field Rust Nurseries.- 8.3 Greenhouse or Growth Chamber Rust Tests.- 8.4 The Pedigree System of Breeding.- 8.5 Off-Season Nurseries.- 8.6 The Bulk System of Breeding.- 8.7 A Modified Bulk System.- 8.8 Backcrossing.- 8.9 Partial or Incomplete Backcrossing.- 8.10 Convergent Backcrossing.- 8.11 Single Seed Descent (SSD).- 8.12 Recurrent Selection.- 8.13 Using Knowledge About the Genetics of Resistance.- 8.14 Durable Resistance.- 8.15 Mutation Breeding for Rust Resistance.- 8.16 Biotechnology and Breeding for Rust Resistance.- 8.17 Hybrid Wheat.- 8.18 Selecting a Method of Breeding for Resistance.- 9 Managing Genetic Diversity to Control Rusts.- 9.1 Introduction.- 9.2 Multilines.- 9.3 Cultivar Mixtures or Blends.- 9.4 Interfield Diversity.- 9.5 Regional Deployment of Genes for Resistance.- 9.6 Conclusions.- 10 The Transfer of Rust Resistance from Alien Species to Wheat.- 10.1 Introduction.- 10.2 Relationships Among Species.- 10.3 The Relatives of Wheat as Sources of Rust Resistance.- 10.4 Transferring Rust Resistance to Wheat from Related Species.- 10.5 The Results of Transfer of Rust Resistance from Alien Species to Wheat.- 10.6 Future Prospects.- References.