Investigations on various aspects of plant-pathogen interactions have the ultimate aim of providing information that may be useful for the development of effective crop disease management systems. Molecular techniques have accelerated the formulation of short- and long-term strategies of disease management. Exclusion and eradication of plant pathogens by rapid and precise detection and identification of microbial pathogens in symptomatic and asymptomatic plants and planting materials by employing molecular methods has been practiced extensively by quarantines and certification programs with a decisive advantage. Identification of sources of resistance genes, cloning and characterization of desired resistance genes and incorporation of resistance gene(s) into cultivars and transformation of plants with selected gene(s) have been successfully performed by applying appropriate molecular techniques. Induction of resistance in susceptible cultivars by using biotic and abiotic inducers of resistance is a practical proposition for several crops whose resistance levels could not be improved by breeding or transformation procedures. The risks of emergence of pathogen strains less sensitive or resistant to chemicals have been reduced appreciably by rapid identification of resistant strains and monitoring the occurrence of such strains in different geographical locations.

Studies on molecular biology of pathogens, infection process and disease resistance, have provided information essentially required to understand the vulnerable stages at which the pathogens can be tackled effectively and to adopt novel strategies to incorporate disease resistance genes from diverse sources and /or to induce resistance of cultivars with desirable agronomic attributes using biotic or abiotic agents. The nature of interaction between the gene products of the pathogen and plant appears to determine the outcome of the interaction resulting in either disease progression or suppression. Transgenic plants with engineered genes show promise for effective exploitation of this approach for practical application. Research efforts during the recent years to sequence the whole genomes of the pathogens and plants may lead to development of better ways of manipulating disease resistance mechanisms enabling the grower to achieve higher production levels and the consumer to enjoy safer food and agricultural products. Experimental protocols included in appropriate chapters will be useful for researchers and graduate students.

Investigations on various aspects of plant-pathogen interactions have the ultimate aim of providing information that may be useful for the development of effective crop disease management systems. Molecular techniques have accelerated the formulation of short- and long-term strategies of disease management. Exclusion and eradication of plant pathogens by rapid and precise detection and identification of microbial pathogens in symptomatic and asymptomatic plants and planting materials by employing molecular methods has been practiced extensively by quarantines and certification programs with a decisive advantage. Identification of sources of resistance genes, cloning and characterization of desired resistance genes and incorporation of resistance gene(s) into cultivars and transformation of plants with selected gene(s) have been successfully performed by applying appropriate molecular techniques. Induction of resistance in susceptible cultivars by using biotic and abiotic inducers of resistance is a practical proposition for several crops whose resistance levels could not be improved by breeding or transformation procedures. The risks of emergence of pathogen strains less sensitive or resistant to chemicals have been reduced appreciably by rapid identification of resistant strains and monitoring the occurrence of such strains in different geographical locations.

Studies on molecular biology of pathogens, infection process and disease resistance, have provided information essentially required to understand the vulnerable stages at which the pathogens can be tackled effectively and to adopt novel strategies to incorporate disease resistance genes from diverse sources and /or to induce resistance of cultivars with desirable agronomic attributes using biotic or abiotic agents. The nature of interaction between the gene products of the pathogen and plant appears to determine the outcome of the interaction resulting in either disease progression or suppression. Transgenic plants with engineered genes show promise for effective exploitation of this approach for practical application. Research efforts during the recent years to sequence the whole genomes of the pathogens and plants may lead to development of better ways of manipulating disease resistance mechanisms enabling the grower to achieve higher production levels and the consumer to enjoy safer food and agricultural products. Experimental protocols included in appropriate chapters will be useful for researchers and graduate students.

Studies on the phenomenon of plant pathogenesis (disease development) have been useful to have a deep insight into the interactions between host plant and the pathogen. Depending on the levels of susceptibility (compatibility) or resistance (incompatibility) of the host plant and virulence of the pathogen, disease development may progress, either leading to symptom expression or result in the suppression of pathogen proliferation. Molecular techniques have been applied to elucidate the nature of interactions between the gene products of the plant and pathogen at cellular and molecular levels. Successful evasion of host’s surveillance system and subsequent activities of metabolites of the pathogen (enzymes and toxins) encoded by pathogen genes counteracting the effects of various defense-related antimicrobial compounds present already or produced by the host plants, after initiation of infection have been critically studied by applying various molecular techniques. In addition to studying various phases of disease development in individual plants, molecular methods have been demonstrated to be effective, in gathering data on various aspects of epidemiology under natural conditions where the interaction of pathogen with populations of plants is influenced significantly by the environmental conditions existing in different ecosystems. This volume focuses on the possibility of applying the knowledge on pathogenesis and molecular epidemiology to determine the vulnerable stages in the life cycles of the pathogens that can be disrupted to achieve more effective disease control.

Studies on the phenomenon of plant pathogenesis (disease development) have been useful to have a deep insight into the interactions between host plant and the pathogen. Depending on the levels of susceptibility (compatibility) or resistance (incompatibility) of the host plant and virulence of the pathogen, disease development may progress, either leading to symptom expression or result in the suppression of pathogen proliferation. Molecular techniques have been applied to elucidate the nature of interactions between the gene products of the plant and pathogen at cellular and molecular levels. Successful evasion of host’s surveillance system and subsequent activities of metabolites of the pathogen (enzymes and toxins) encoded by pathogen genes counteracting the effects of various defense-related antimicrobial compounds present already or produced by the host plants, after initiation of infection have been critically studied by applying various molecular techniques. In addition to studying various phases of disease development in individual plants, molecular methods have been demonstrated to be effective, in gathering data on various aspects of epidemiology under natural conditions where the interaction of pathogen with populations of plants is influenced significantly by the environmental conditions existing in different ecosystems. This volume focuses on the possibility of applying the knowledge on pathogenesis and molecular epidemiology to determine the vulnerable stages in the life cycles of the pathogens that can be disrupted to achieve more effective disease control.