ABSTRACT
In an ecosystem, diverse but balanced biological factors arising from long-term coevolution, interact with host plants and soilborne microbial plant pathogens in different environmental conditions. Under wild ecosystem, the plants and the pathogens coexisted in a balanced level. Ultimately increase in susceptibility of crop plants forced the researchers to search for resistance gene(s) in wild relatives of crop plant species. Thus, the crops became susceptible, not only to the soilborne microbial plant pathogens present in a geographic location, but also to the exotic plant pathogens introduced through seeds and propagules. Microbial pathogens – fungi and bacteria – may exist as free-living organisms in the soil and induce disease symptoms, after entry through roots of susceptible plants. Exposure to ultraviolet radiation may inactivate or kill the microorganisms depending on the dose and duration of exposure. Soilborne microbial plant pathogens form an important group that negatively impact crop production by adversely affecting soil health.
