FIG. 2.

Culturability and viability of R. solanacearum in sterile soil. Cells of AS108 were inoculated into sterile soil as described in Materials and Methods. At various times, soil samples were removed, bacteria were isolated, and the concentrations of viable (open symbols) and culturable (solid symbols) forms of bacteria were determined as described in Materials and Methods. Circles, uninoculated soil; squares, inoculated soil; diamonds, inoculated soil supplemented with cupric sulfate. Also shown are viabilities determined at the terminal time point by the Kogure assay with inoculated soil (▴) and inoculated soil supplemented with cupric sulfate (▵). The results are the averages of three trials. Bars, standard errors.