Root Diseases And Soil Borne Pathogens

Population dynamics of pathogens in soil. Genetical aspects of pathogenic and saprophytic behavoir in root-infecting fungi. Effect of soil moisture and aeration on fungal activity with root diseases. Effect of root exudates on root infection. Root diseases of forest crops. Root diseases of tropical plantation crops. Crop grouth responses to soil fumigation.

Introduction; Soilborne diseases of specific crops; Ecology and control.

Root disease epidemics, because much of the activity takes place in soil and out of sight, pose special challenges to growers who seek to manage them and to scientists who study them. All relevant topics of root disease epidemics and their management are presented: The critical aspects of specific disease components including inoculum, host roots, mycorrhiza and the soil environment are explored. Challenges of disease assessment and the temporal and spatial aspects of epidemic development are considered, and approaches to root disease management including host resistance, chemical, biological and cultural management are discussed in detail. The book fulfills the needs of researchers, teachers, and practitioners of plant pathology.

Collection of soil samples. Isolation of groups of microorganisms from soil. Enumeration and observation of microorganisms in situ. Microorganisms in the rhizosphere. Isolation of plant pathogens from soil. Isolation of plant pathogens from roots. Control of soil environment. Extraction of soil solutions. Respiration and enzyme activity. Growth and survival. Root exudates. Screening soil microorganisms for antagonism. Testing for antibiotic activity. Production, stability, and activity of antibiotics in soil. Biological control. Culture media.

In the last decade, enormous progress has been made on the physiology of plant roots, including on a wide range of molecular aspects. Much of that progress has been captured in the chapters of this book. Breakthroughs have been made possible through integration of molecular and whole-plant aspects. The classical boundaries between physiology, biochemistry and molecular biology have vanished. There has been a strong focus on a limited number of model species, including Arabidopsis thaliana. That focus has allowed greater insight into the significance of specific genes for plant development and functioning. However, many species are very different from A. thaliana, in that they are mycorrhizal, develop a symbiosis with N2-fixing microsymbionts, or have other specialised root structures. Also, some have a much greater capacity to resist extreme environments, such as soil acidity, salinity, flooding or heavy-metal toxicities, due to specific adaptations. Research on species other than A. thaliana is therefore pivotal, to develop new knowledge in plant sciences in a comprehensive manner. This fundamental new knowledge can be the basis for important applications in, e.g., agriculture and plant conservation. Although significant progress has been made, much remains to be learnt. It is envisaged that discoveries made in the recent past will likely lead to major breakthroughs in the next decade.

Ecology of Root Pathogens discusses the significance of fungi infecting the roots, and emphasizes the significant diseases of roots and their symptoms. This book also names the genera and species of fungi that cause diseases of roots, and classifies and characterizes the root and pathogen interaction in soil. The book describes the behavior of plant pathogenic bacteria, such as Agrobacterium, Corynebacterium, Xanthomonas, Pseudomonas, Erwinia, and Streptomyces. It also explores how plants and plant-produced stimuli affect the associated population of plant parasitic nematodes and how these plant parasitic nematodes affect higher plants in certain ways. In addition, this book discusses the morphology, classification, nomenclature, multiplication and translocation of viruses infecting the plants. It also describes the symptoms of the virus infection in roots. The book includes a discussion on the fundamentals of biological control, which include the pathosystem concept, the behavior of the soil microflora in the soil, the reservoirs for infection, the processes of pathogen decline, and the integrated effects on the decline of the pathogen. This discussion on biological control also presents the natural and artificially induced biological control. This book will be of great value to soil microbiologists and plant pathologists.