Preliminary screening for antagonistic activity in vitro
This test was performed to screen antagonistic activity of obtained
isolates from soil against R. solanacearum according to the method
described by Li et al. (2008b). Cultures of R. solanacearum was
grown overnight in nutrient broth; 0.5 ml of the liquid culture was
mixed with 15 ml lukewarm molted nutrient agar in sterile plates and
allowed to solidify. Afterwards, each tested isolate was spotted on
the surface of agar plates and incubated them at 28°C for 72 h.
Consequently, those bacteria that displayed positive inhibition
activity were considered as antagonistic isolates and selected for
further investigations.