Individual and Combined Effects of Azospirillum brasilense and Pseudomonas fluorescens on Biomass Yield and Ajmalicine Production in Catharanthus roseus

In the present study, the effect of different plant growth promoting rhizobacteria (PGPR) like Azospirillum brasilense and Pseudomonas fluorescens on growth parameters and the production of terpenoid indole alkaloids are investigated in two varieties ‘rosea’ and ‘alba’ of Catharanthus roseus. The production of IAA by the PGPR has taken as main criteria in the selection of PGPRs for the seed and seedling treatments. The maximum ajmalicine content recorded in the combined inoculation of Azospirillum brasilense + Pseudomonas fluorescens in ‘rosea’ variety on 90 DAP (0.700 mg g dry weight). 1 The control plants performed far lower than the individual and combined inoculation of PGPR treatments in both seed and seedling treatment in ‘rosea’ and ‘alba’ varieties. From the results of this investigation, it can be concluded that, the seed priming and seedling treatments of native PGPRs can be used as a good tool in the enhancement of biomass yield and alkaloid contents in medicinal plant cultivation, as it provides an ecofriendly approach.