The Nature of Wilt Diseases of Plants

Hardcover  182 pages, 32 photographs and illustrations  ISBN 0890540748      £47.00

The ultimate objective of this book is to advance the ongoing process of modeling vascular diseases of plants, especially Fusarium wilt of tomato. The book features a review of wilt diseases and then develops a framework in which past, present, and future findings can be classified and correlated. The contents are as follows:

Preface

Introduction

The Production, Persistence, and Presentation of Inoculum

• Growth and Reproduction in Moribund Tissues of the Host
• The Persistence of Fusarium in the Soil
• The Colonization of Root Surfaces
• Suscept-Parasite Contacts--The Transition Between Persistence in the Soil and Extended Parasitic Growth
• Disease Expression in Conducive Versus Suppressive Soils
• Fusarium Crown and Root Rot--A Special Case
• Modelling the Survival of Fusarium and Its Initial Contact with the Host

Defence Strategies of the Plant

• Innate Structural Barriers
• Recognition Phenomena
• General Defence Responses

Determinative Phase I: Success or Failure of the Pathogen in Penetrating to the Vascular System of the Host

Determining Phase II: Success or Failure of the Pathogen in Colonizing the Vascular System

• Modelling the Interaction Between Host and Parasite Within the Vascular System
• Defining Parameters of the Model
• Defining Components Within the Model
• Defenses in the Lateral Direction
• Defence in a Longitudinal Direction
• A Perspective on Vascular Occlusion
• The Activation of the Hormonal System of the Host
• Vascular Gels and Gums and Vessel Coatings
• Tyloses, Isodiametric Growth, and Increased Vascularization
• The Synthesis of Stress Metabolites by the Host in Response to Infection
• The Accumulation of Phenolics Following Infection and Their Relation to the Resistance Process
• The Lignification and Suberization of Infected Tissues
• Phytoalexins Produced in Response to Stress
• Other Host Responses That Contribute to Defence
• The Defence Strategies of the Plant
• Colonization of the Vascular System by the Pathogen
• Defining Pathogen Factors That Disrupt Host Defenses
• Avoiding or Overcoming Recognition
• Avoiding or Overcoming Callose Deposition
• Avoiding or Overcoming Vascular Gelation
• Avoiding or Overcoming Vascular Blockage by Tylose Occlusion or Vessel Crushing
• Avoiding or Overcoming Stress Metabolites
• The Suppression of Responses as Reflected in Respiration
• Some Thoughts on the Suppressions of Responses

The Expressive Phase of the Disease

• The Causes of Wilting--The Great Debate
• The Evidence for Vascular Plugging and the Failure of the Water Supply
• The Toxin Hypothesis in Relation to Symptom Expression
• A Role for Toxins Produced by the Pathogen?

Genetic Variation in the Host and Pathogen

• Resistance of Tomato to Fusarium oxysporum f. sp. lycopersici Race 1
• Resistance of Tomato to Fusarium oxysporum f. sp. lycopersici Races 2 and 3 and to F.o. f.sp. radicis-lycopersici
• Resistance of Tomato to Related Disease Organisms
• Genetic Variation and Taxonomy of the Pathogens
• Genetic Studies of Fusarium oxysporum
• Classification and Nomenclature of Host and Pathogen in Terms of Their Interactions
• The Cataloging and Mapping of Genes

Environmental Factors in Disease Development

• Temperature
• Light
• Soil Moisture and Aeration
• The Effect of Nutrients on Wilt Development
• Calcium Nutrition and Soil pH
• Nitrogen Nutrition
• The Effect of Nonpathogenic Microflora on Disease Development
• The Effect of Nematode Infections on Wilt Expression

Control Measures

• Reducing Inoculum Load in the Soil
• The Problem of Soil Reinfestation
• The Control of Soil Reinfestation
• The Use of Systemic Chemicals for Wilt Control
• The Limitations of Chemical Control
• The Use of Biological Control
• The Selection, Development, and Maintenance of Suppressive Soils
• Altering the Soil Nutrients
• The Use of Resistant Cultivars
• Building a Strategy for Control

A Look Toward the Future

References