Host-Pathogen Interactions in Plant Disease (Hardcover)

Contents

Preface

1 Introduction

Text

2 Virulence Structure of Puccinia graminis Populations

2.1 Introduction

2.2 The Dissociation of Virulence for Genes Sr6 and Sr9d in Canada

2.3 The Association of Virulence for Genes Sr6 and Sr9d in the United States and Mexico

2.4 The Association and Dissociation of Virulence for Gene Sr9d, on the One Hand, and Genes Sr9a, Sr9b, or Sri5, on the Other

2.5 The Involvement of Dates and Temperature

2.6 Loss of Virulence Associations in Race 15B-1

2.7 The Dissociation of Virulence for Genes Sr6 and Sr9e

2.8 The Concept of Fitness

2.9 The Dissociation of Virulence for Gene Sr9e from Virulence for Genes Sr9a, Sr9b, and Sri15

2.10 Matching Virulence and the ABC-XYZ System

2.11 Genes Sr7b, SrlO, Srll, and SrTtl in the XYZ Group

2.12 Virulence Dissociation and Stabilizing Selection

2.13 Stabilizing Selection in Vertical Resistance

2.14 Stabilizing Selection and the Horizontal Resistance Equivalent

2.15 Stabilizing Selection Inhibiting Epidemics

2.16 The Second Gene-for-Gene Hypothesis

2.17 Breeding Wheat for Stem Rust Resistance

2.18 Multilines and Mixed Varieties

2.19 Possible Supergenes

2.20 Oat Stem Rust

2.21 Results with Some Other Pathogens

2.22 Some Conclusions

3 Races of Pathogens

3.1 Introduction

3.2 Additive and Multiplicative Increase

3.3 Genes and Taxa

3.4 The Ineptness of Fixed Races

3.5 Change as the Result of Gene Flow

3.6 Computerized Surveys

3.7 Discussion

4 The Influence of the Host

4.1 Introduction

4.2 Virus Diseases

4.3 Bacterial Diseases

4.4 Fungus Diseases

4.5 The Role of Mutations

4.6 Stabilizing Selection

4.7 Associated Virulence and Destabilizing Selection

4.8 An Illustrative Suggestion

4.9 Epistatic Interaction and Mathematical Models

4.10 Variable Mutation Rates

4.11 Genetic, Phenotypic, and Epidemiological Mutation

5 Host and Pathogen in a Two-Variable System

5.1 Introduction

5.2 The Geometric Illustration

5.3 Illustration by Analysis of Variance

5.4 Limitations of the Analysis of Variance Technique

5.5 Degrees of Freedom as a Limitation

5.6 Host and Pathogen Ranges as Limitations

5.7 Glossary

6 The Gene-for-Gene Hypothesis

6.1 Introduction

6.2 Biotrophy and Gene-for-Gene Systems

6.3 Possible Gene Duplication

6.4 Multiple Alleles with the Same Recognition System

6.5 Pseudoalleles with Different Recognition Systems

6.6 The Quadratic Check versus the Minimum Test for the Hypothesis

6.7 Susceptibility Is Specific

6.8 The Numerical and Chemical Implications of the Hypothesis

6.9 The Axenic Culture Fallacy

6.10 DNA

6.11 RNA

6.12 Protein

6.13 The Protein-for-Protein Hypothesis

6.14 Specific and Unspecific Receptors

6.15 Saccharides

6.16 Discussion

6.17 Ockham's Razor

7 Some Thermodynamic Background

7.1 Introduction

7.2 Free Energy, Enthalpy, Temperature, Entropy

7.3 Thermodynamic Clues

7.4 The Solvent Effect

7.5 A Possible Thermodynamic Sink

8 Continuously Variable Resistance to Disease

8.1 Introduction

8.2 The Polygene Model

8.3 Four Other Models

8.4 Polygenic Resistance versus Breeding for Resistance

8.5 The Error of Expecting Safety in Numbers

8.6 Experimental Evidence about Gene Numbers

8.7 The Central Role of Additive Variance

8.8 Additive Variance and Stable Resistance

8.9 Additive Resistance in Gains by Selection

8.10 Transgressive Segregation and Polygenic Resistance

8.11 Different Methods of Analyzing Variance

9 Epidemiology of Resistance to Disease

9.1 Introduction

9.2 Disease Progress Curves and Resistance

9.3 Slow Rusting and Incomplete Vertical Resistance

9.4 Horizontal Resistance That Delays the Start of an Epidemic

9.5 Resistance as Delayed Adult-Plant Susceptibility

9.6 Slow Rusting and Horizontal Resistance

9.7 The Ineptness of Some Infection Rate Averages

9.8 Testing for Resistance as Delayed Susceptibility

9.9 Young-Plant Susceptibility

9.10 Adult-Plant Resistance

10 The Anatomy of Epidemics

10.1 Introduction

10.2 The Logistic Equation Is Not a Model

10.3 The Background to Modeling

10.4 The Progeny/Parent Ratio in Reality

10.5 The Progeny/Parent Ratio in an Equation

10.6 The Effect of Dwindling Inoculum

10.7 The Role of the Latent Period

10.8 Epidemics with High Progeny/Parent Ratios

10.9 Epidemics with Low Progeny/Parent Ratios

10.10 The Threshold Condition for an Epidemic

10.11 A Varying Progeny/Parent Ratio

10.12 Internal Checks of Accuracy

10.13 Analysis versus Synthesis

10.14 Two Models: Plateaus and Peaks

10.15 Appendix about the Tables

11 The Spread of Disease

11.1 Introduction

11.2 Background

11.3 The Spread of Monocyclic Disease

11.4 The Spread of Poly cyclic Disease

11.5 The Rate of Spread of Fast Epidemics

11.6 Monocyclic and Poly cyclic Disease

11.7 The Effect of the Scatter of Disease on the Infection Rate

Bibliography

Index