Microbial Plant Pathogens-Detection and Disease Diagnosis: : Fungal Pathogens, Vol.1

V. 1 Fungal pathogens : Plants are infected by different microbial pathogens, of which fungal pathogens form the highly evolved and earliest recognized group. The morphological, biological, biochemical and physiological characteristics have been used for the detection, identification and differentiation of fungal pathogens up to species level. Pathogenicity on a set of differential host plant species or crop cultivars has been useful for the identification of physiologic races existing within a morphologic species/variety. As the techniques based on the above mentioned characteristics require long time and yield inconsistent results, the need for the development of techniques with greater accuracy, reliability, reproducibility and capable of providing the results rapidly was realized. Immunoassays have been shown to be effective in detecting several fungal pathogens present in plants, planting materials, soil, water and air. Development of monoclonal antibody technology has greatly enhanced the sensitivity and specificity of detection, identification and differentiation of fungal species and varieties/strains. Nucleic acid-based techniques involving hybridization of probes with complementary sequences of the target pathogen(s) or amplification of specific sequences of the target pathogen DNA/fragment have been demonstrated to be the most efficient among the diagnostic techniques currently available. This volume provides exhaustive information on various methods of detection of fungal pathogens and the diagnosis of the diseases caused by them based on extensive literature search that will be useful to the researchers, teachers and graduate students of different disciplines of biological sciences, in addition to the extension pathologists, personnel of plant quarantines and certification programs. Presentation of a large number of protocols is a unique feature of this volume to facilitate selection of appropriate techniques for different investigations Viruses, with the primitive structural features are capable of causing diseases in all life forms on the earth. With limited morphological characteristics of the virus particles and lack of physiological functions, the need for the development of techniques based on the characteristics of the viral proteins and genomic nucleic acids was realized in order to detect, identify, differentiate and quantify viruses in the infected plants/planting materials with or without symptoms of infection. Immunoassays based on the antigenic properties of viral capsid proteins have been successfully applied for the detection of viruses in the symptomatic and asymptomatic crop and weed host plant species as well as in the vectors that are involved in the transmission of the viruses infecting crop plants. Development of monoclonal antibody technology has enhanced the sensitivity and specificity of immunoassays especially applied for the differentiation of strains of viruses with different virulence levels. Nucleic acid-based techniques have been demonstrated to have higher levels of sensitivity, specificity, reliability, reproducibility and rapidity. The viroids with only an RNA molecule have been detected by techniques based on the biological characteristics in certain cases. Application of immunoassays for viroid detection is not feasible because of the absence of a protein component that is present in the viruses. Nucleic acid-based techniques are the most reliable and sensitive tests for detection, identification and differentiation of viroids present in plants and planting materials. With the aim of providing a comprehensive knowledge of detection of viruses and viroids and diagnosis of the diseases caused by them, information distilled from extensive literature search is presented to fulfil the requirements of the researchers, teachers and graduate students of various disciplines of biological sciences. Inclusion of numerous protocols in appropriate chapters as appendix is a unique feature of this volume to enable the scientists to select the suitable methods for the various investigations Morphological, biological, biochemical and physiological characteristics have been used for the detection, identification and differentiation of fungal pathogens up to species level. Tests based on biological characteristics are less consistent. Immunoassays have been shown to be effective in detecting fungal pathogens present in plants and environmental samples. Development of monoclonal antibody technology has greatly enhanced the sensitivity and specificity of detection, identification and differentiation of fungal species and varieties/strains. Nucleic acid-based techniques involving hybridization with or amplification of unique DNA have provided results rapidly and reliably. Presentation of a large number of protocols is a unique feature of this volume. Front Matter....Pages i-xxiii Introduction....Pages 1-4 Detection of Fungal Pathogens in Plants....Pages 5-199 Detection of Fungal Pathogens in the Environment....Pages 201-244 Assessment of Variability in Fungal Plant Pathogens....Pages 245-272 Diagnosis of Fungal Diseases of Plants....Pages 273-284 Back Matter....Pages 285-291