ABSTRACT
The bacterial plant pathogens in every genus are specific in their host range and on this basis are further divided into group or species. Among the group or species these are further divided into pathovars based on the plant species in which they initiate the disease and cause symptoms, for example, Xanthomonas attacking a strawberry plant is specific to its host and is classified as X. fragariae. The genus Xanthomonas is subdivided into eight groups/species on the basis of various biochemical tests/characteristics, and each species is further divided into pathovars on the basis of the host they infect. The genus Pseudomonas is subdivided into eight groups/species and further into pathovars on the basis of host they infect. Thus, biochemical tests play an important tool in the differentiation of the bacterial isolate into separate distinct species or biovar.
