Isolation and characterization of rhizobacteria and their effects on root extracts of Valeriana officinalis.
Plant growth promoting rhizobacteria (PGPR) are a group of microorganisms which can enhance growth parameters of host plants and can be used as biofertilizers. Valerian (Valeriana officinalis) is a perennial herb which is used as a medicinal plant. In the current study 40 colonies of bacteria were isolated from the rhizosphere of valerian by growing in various enriched and selective media including S1 and King B, crystal violet agar and methyl red agar.