ABSTRACT

Identification of various strains of plant pathogens has traditionally been based upon microscopic examination of morphological and biochemical characters and growth characteristics of the pathogen on specific media. Variations in the morphological characters exist and lead to difficulties in accurate identification by traditional methods. Molecular techniques have been used to study genetic diversity and evolutionary origins in populations of many different genera. Molecular detection can generate rapid accurate results enough to be useful for disease management decisions. To study the molecular variability the molecular techniques like hybridization-based techniques, polymerase chain reaction-based techniques, and guanine-plus-cytosine-ratio–based techniques are generally used. The chapter deals with all these techniques along with other molecular based techniques which can be employed in the study of plant pathogenic bacteria. Most plant pathogenic bacteria are known to harbor plasmids carrying genes responsible for virulence, antibiotics resistance, and exopolysaccharide production.