This first volume of a two-volume set introduces disease-causing microorganisms including oomycetes, fungi, bacteria, and viruses found in soils. It focuses on the biology, detection, and identification of soilborne bacterial, fungal, and viral plant pathogens.
Soilborne microbial plant pathogens including oomycetes, fungi, bacteria and viruses cause several economically important destructive diseases and the symptoms of infection can be recognized only after the pathogen has invaded many tissues primarily vascular tissues of susceptible plants. This condition places formidable challenges in investigating different aspects of host-microbial pathogen interactions.
Early detection of infection and precise identification, differentiation, and quantification of the microbial plant pathogens in plants, soil and water sources are essential requirements for development of effective tactics to reduce the incidence and spread of the diseases caused by them. As the microbial plant pathogens differ in their virulence and sensitivity to the environment and chemicals applied, it is imperative to assess the extent of variability in the concerned pathogens.
This first volume of a two-volume set introduces disease-causing microorganisms including oomycetes, fungi, bacteria, and viruses found in soils. It focuses on the biology, detection, and identification of soilborne bacterial, fungal, and viral plant pathogens. This volume discusses various techniques based on biological, immunological and genetic properties of the pathogens indicating their advantages and limitations for selecting the appropriate technique to fulfill the requirements.
Features:
- Presents techniques useful for detection, identification, quantification of microbial plant pathogens in plants, soil, and irrigation water from waterbodies.
- Highlights subversive activities of viruses, resulting in the breakdown of host defense systems.
- Discusses RNA silencing in infected plants by viruses and posttranscriptional gene silencing (PTGS) functioning as an endogenous mechanism in plants against virus infection.
- Presents information on methods of assessment of genetic variability and sensitivity of microbial plant pathogens to chemicals and adverse environmental conditions.
Preface
1 Introduction
1.1 Economic Importance and Distribution of Diseases Caused by Soilborne
Microbial Plant Pathogens........ 1
1.2 Concepts and Implications of Infection by Soilborne Microbial Plant
Pathogens........................................ 1
1.3 Nature of Soilborne Microbial Plant Pathogens Causing Crop
Diseases...................................................... 3
1.3.1 Pathogen
Biology......................................................................
....................................................... 3
1.3.2 Ecological and Epidemiological
Perspectives.................................................................
................. 3
1.4 Principles of Management of Crop Diseases Caused by Soilborne Microbial
Pathogens............................ 3
1.4.1 Prevention of Pathogen Introduction and Inoculum
Production...................................................... 3
1.4.2 Inhibition of Pathogen
Development..................................................................
.............................. 4
1.5 Development of Integrated Disease Management
Systems......................................................................
..... 4
References...................................................................
.............................................................................
................ 4
Chapter 2 Detection and Identification of Soilborne Fungal Plant
Pathogens....................................................................
...... 7
2.1 Detection of Fungal Pathogens In Soil
Environments.................................................................
.................. 7
2.1.1 Isolation-Based
Methods......................................................................
............................................ 7
2.1.1.1 Baiting
Assays.......................................................................
........................................... 8
2.1.1.2 Direct Plating of Soil
Samples......................................................................
.................. 11
2.1.1.3 Plating of Water
Samples......................................................................
.......................... 12
2.1.2 Physical and Chemical
Methods......................................................................
.............................. 13
2.1.3
Immunoassays.................................................................
............................................................... 16
2.1.3.1 Enzyme-Linked Immunosorbent
Assay........................................................................
.. 17
2.1.3.2 Dipstick
Immunoassay..................................................................
.................................. 20
2.1.3.3 Lateral Flow
Devices......................................................................
................................ 21
2.1.3.4 Dot Immunobinding
Assay........................................................................
..................... 21
2.1.3.5 Tissue Blot
Immunoassay..................................................................
............................. 22
2.1.3.6 Western Blot
Analysis.....................................................................
................................ 22
2.1.3.7 Immunofluorescence
Assay........................................................................
.................... 22
2.1.3.8 Immunosorbent Electron
Microscopy...................................................................
......... 22
2.1.4 Nucleic Acid-Based
Techniques...................................................................
.................................. 22
2.1.4.1 Fluorescence
Microscopy...................................................................
............................ 23
2.1.4.2 Hybridization
Methods......................................................................
............................. 23
2.1.4.3 Polymerase Chain Reaction-Based
Assays.....................................................................
24
2.2 Assessment of Variability in Soilborne Fungal
Pathogens....................................................................
...... 59
2.2.1 Variability in Biological
Characteristics..............................................................
.......................... 59
2.2.2 Variability in Vegetative
Compatibility................................................................
.......................... 60
2.2.3 Variability in Genomic
Characteristics..............................................................
............................ 62
2.2.3.1 Nucleic Acid Hybridization
Techniques...................................................................
...... 63
2.2.3.2 Polymerase Chain Reaction-Based
Methods.................................................................. 63
References...................................................................
.............................................................................
.............. 75
Chapter 3 Biology of Soilborne Fungal Plant
Pathogens....................................................................
.................................... 89
3.1 Biological Characteristics of Fungal
Pathogens....................................................................
...................... 89
3.1.1 Disease Incidence and
Distribution.................................................................
............................... 89
3.1.2 Disease Cycles of Fungal
Pathogens....................................................................
.......................... 91
3.1.2.1 Production of Pathogen
Propagules...................................................................
............. 91
3.1.2.2 Survival and Dispersal of Fungal
Pathogens..................................................................
96
3.1.2.3 Transmission of Soilborne Fungal Pathogens through
Vectors.................................... 100
3.1.2.4 Host Range of Fungal
Pathogens....................................................................
.............. 101
3.1.2.5 Disease Complexes of Soilborne Fungal Pathogens and
Nematodes........................... 103
3.2 Genetic Characteristics of Fungal
Pathogens....................................................................
........................ 104
3.2.1 Pathogenicity of Fungal
Pathogens....................................................................
.......................... 104
3.2.2 Production of Toxic Metabolites and Enzymes by Fungal
Pathogens......................................... 108
3.3 Process of Infection of Fungal
Pathogens....................................................................
..............................112
3.3.1 Germination of
Spores.......................................................................
...........................................112
3.3.2 Penetration and Colonization of Host
Tissues......................................................................
........ 115
3.3.3 In Planta Expression of Fungal Pathogen
Genes........................................................................
.. 129
3.3.4 Molecular Basis of Interactions between Host Plants and Fungal
Pathogens.............................. 135
3.3.5 Influence of Environment on Disease
Development..................................................................
.. 142
References...................................................................
.............................................................................
.............143
Chapter 4 Detection and Identification of Soilborne Bacterial Plant
Pathogens..................................................................
155
4.1 Detection of Bacterial
Pathogens....................................................................
.......................................... 156
4.1.1 Isolation-Dependent
Methods......................................................................
................................ 156
4.1.1.1 Use of Indicator
Plants.......................................................................
........................... 156
4.1.1.2 Use of Selective
Media........................................................................
......................... 156
4.1.1.3 Use of
Bacteriophages...............................................................
................................... 158
4.1.1.4 Biochemical and Physical
Methods......................................................................
........ 158
4.1.2 Isolation-Independent
Methods......................................................................
.............................. 159
4.1.2.1
Immunoassays.................................................................
.............................................. 159
4.1.2.2 Nucleic Acid-Based
Techniques...................................................................
................ 163
4.2 Variability in Bacterial
Pathogens....................................................................
..........................................178
4.2.1 Variability in Cultural
Characteristics..............................................................
.............................178
4.2.2 Variability in
Pathogenicity................................................................
...........................................178
4.2.3 Variability in Biochemical
Properties...................................................................
....................... 180
4.2.4 Variability in Physical
Properties...................................................................
.............................. 180
4.2.5 Variability in Immunological
Properties...................................................................
................... 180
4.2.6 Variability in Genomic Nucleic Acid
Characteristics..............................................................
.... 181
References...................................................................
.............................................................................
............ 187
Chapter 5 Biology of Soilborne Bacterial Plant
Pathogens....................................................................
.............................. 195
5.1 Disease Cycles of Bacterial Plant
Pathogens....................................................................
........................ 195
5.1.1 Ralstonia
solanacearum.................................................................
.............................................. 195
5.1.1.1 Disease Incidence and
Distribution.................................................................
............. 195
5.1.1.2 Host Range and Sources of
Infection....................................................................
....... 196
5.1.1.3 Modes of Dispersal of Bacterial
Pathogens..................................................................
197
5.1.1.4 Survival of the
Pathogen.....................................................................
.......................... 198
5.1.1.5 Process of Infection of Susceptible
Plants....................................................................
199
5.1.2 Pectobacterium spp. and Dickeya
spp..........................................................................
................ 208
5.1.2.1 Disease Incidence and
Distribution.................................................................
............. 208
5.1.2.2 Host Range and Sources of
Infection....................................................................
....... 208
5.1.2.3 Modes of Dispersal of
Pathogens....................................................................
............. 209
5.1.2.4 Process of Infection of Susceptible
Plants....................................................................
210
5.1.3 Streptomyces
spp..........................................................................
................................................ 213
5.1.3.1 Disease Incidence and
Distribution.................................................................
............. 213
5.1.3.2 Pathogenicity and Host
Range........................................................................
.............. 213
5.1.4 Agrobacterium
spp..........................................................................
..............................................216
5.1.4.1 Disease Incidence and
Distribution.................................................................
..............216
5.1.4.2 Process of
Infection....................................................................
.................................. 217
5.1.5 Xanthomonas
spp..........................................................................
............................................... 221
5.1.5.1 Disease Incidence and
Distribution.................................................................
............. 221
5.1.5.2 Process of
Infection....................................................................
.................................. 222
5.1.6 Clavibacter
michiganensis................................................................
........................................... 224
References...................................................................
.............................................................................
............ 225
Chapter 6 Detection and Biology of Soilborne Viral Plant
Pathogens....................................................................
............. 233
6.1 Detection of Soilborne
Viruses......................................................................
............................................ 234
6.1.1 Detection of Viruses with Abiotic
Transmission.................................................................
......... 234
6.1.1.1 Biological
Methods......................................................................
................................. 234
6.1.1.2
Immunoassays.................................................................
.............................................. 234
6.1.1.3 Polymerase Chain Reaction-Based
Assays...................................................................
235
6.1.2 Detection of Viruses with Biotic
Transmission.................................................................
........... 236
6.1.2.1 Viruses Transmitted by Fungal
Vectors......................................................................
.. 236
6.1.2.2 Detection of Viruses Transmitted by
Nnematodes........................................................ 243
6.2 Biology of Soilborne
Viruses......................................................................
............................................... 247
6.2.1 Viruses with Abiotic
Transmission.................................................................
.............................. 248
6.2.2 Viruses with Biotic
Transmission.................................................................
................................ 249
6.2.2.1 Viruses Transmitted by Fungal
Vectors......................................................................
.. 249
6.2.2.2 Viruses Transmitted by Nematode
Vectors...................................................................
252
6.2.3 Process of
Infection....................................................................
.................................................. 254
6.2.4 Mechanisms of Transmission of Viruses by
Vectors....................................................................
255
6.2.5 Movement of
Viruses......................................................................
.............................................. 258
6.2.5.1 Movement of Viruses with Abiotic
Transmission......................................................... 258
6.2.5.2 Movement of Viruses Transmitted by Fungal
Vectors.................................................. 259
6.2.5.3 Movement of Viruses Transmitted by Nematode
Vectors............................................. 261
6.2.6 Role of RNA Silencing in Virus Disease
Development...............................................................
262
References...................................................................
.............................................................................
............ 265
Chapter 7 Ecology and Epidemiology of Soilborne Microbial Plant
Pathogens..................................................................
273
7.1 Nature and Functions of
Soils........................................................................
........................................... 273
7.1.1 Interactions of Microorganisms with Components of
Soils......................................................... 273
7.1.1.1 Interactions among
Microorganisms...............................................................
............. 273
7.1.2 Pathogen Suppression in
Soils........................................................................
............................. 274
7.2 Influence of Agricultural Practices On Soil
Microorganisms...............................................................
..... 277
7.2.1 Cropping
Systems......................................................................
.................................................. 277
7.2.2
Tillage......................................................................
..................................................................... 278
7.2.3 Application of
Nutrients....................................................................
........................................... 278
7.2.4 Irrigation
Practices....................................................................
................................................... 278
7.3 Epidemiology of Soilborne Crop
Diseases.....................................................................
........................... 280
7.3.1 Components of Epidemics of Soilborne
Diseases.....................................................................
... 281
7.3.1.1 Dynamics of Fungal Pathogen-Host Plant
Interactions................................................ 281
7.3.1.2 Dynamics of Host-Bacterial Pathogen
Interactions...................................................... 296
7.3.1.3 Dynamics of Host-Viral Pathogen
Interactions............................................................ 301
7.4 Forecasting Systems For Diseases Caused by Soilborne Microbial
Pathogens........................................ 304
7.4.1 Pathogen-Based
Forecasting..................................................................
...................................... 305
7.4.2 Pathogen Distribution-Based
Forecasting..................................................................
.................. 306
7.4.3 Environment-Based
Forecasting..................................................................
................................ 306
7.4.4 Management-Based
Forecasting..................................................................
................................ 308
References Index
Prof. P. Narayanasamy was awarded the B.Sc.(Ag.) (1958), M.Sc.(Ag.) (1960), and Ph.D. (1963) degrees by the University of Madras and later the Rockefeller Foundation Fellowship to pursue Postdoctoral research on Rice Virus diseases at the International Rice Research Institute, Philippines during 1966 1967. He served as the Virus Pathologist at the Indian Agricultural Research Institute, New Delhi during 1969 1970. He returned to his Alma Mater which was upgraded as the Tamil Nadu Agricultural University (TNAU), Coimbatore in 1971. He was appointed as the Associate Professor and promoted later as the Professor and Head of the Department of Plant Pathology. He was elected as the Fellow of Indian Phytopathological Society, New Delhi. He functioned as the Editor of the Madras Agricultural Journal published from the Tamil Nadu Agricultural University Campus and as member of editorial committees of the Plant Pathology Journals published in India. He was invited to participate as the lead speaker and chairman of sessions in the National Seminars held in India.
As a researcher in Plant Pathology, he was the leader of the projects on diseases of rice, legumes and oilseeds. He organized the National Seminar for the Management of Diseases of Oilseed Crops. His research on antiviral principles yielded practical solutions for the management of virus diseases affecting various crops. He published over 200 research papers in national and international journals. He was the Principal Investigator of several research projects funded by the Department of Science and Technology, Government of India, New Delhi and the International Crops Research Institute for Semi-Arid Tropics, Hyderabad, India. He continues to share his experience and knowledge with the staff and graduate students of the Department of Plant Pathology, TNAU, Coimbatore. As a teacher, he taught courses on Plant Virology, Molecular Biology, Physiopathology, and Crop disease management for Master and Doctoral programs. Under his guidance, graduate students (25) and research scholars (15) earned Master and Doctoral Degrees respectively. With long experience and in-depth knowledge on various aspects of microbial plant pathogens and crop disease management, he has authored 18 books published by leading publishers like Marcel Dekker, John Wiley, Science Publishers, The Haworth Press, and Springer Science. These publications cover various aspects of Plant Pathology and serve as source of information and well received by the intended audience.
As the social obligation, he is deeply involved in the social welfare activities to help the orphaned old and infirm people, as well as children through Udavum Karangal (Coimbatore), HelpAge (New Delhi), Global Cancer Concern (New Delhi), CRY (Bangalore), and The Hindu Mission Hospital (Chennai) to lessen the sufferings of needy persons. As one interested in literature and spirituality, he has composed poems in Tamil and English and published two collections of poems to inculcate self confidence in the youth and spiritual exploration for the mature people.
Lisainfo e-raamatute kohta