Effect of Rhizobacterial Inoculation on Withaferin - A Content of Ashwagandha (Var. Jawahar 20) Roots

Plant growth promoting rhizobacteria viz., Azospirillum, Azotobacter, Bacillus and Pseudomonas were isolated from rhizosphere soil and ischolar_mains of ashwagandha plants collected from various locations in Tamil Nadu. The isolated strains were characterized by morphological, physiological and biochemical tests and were examined for nitrogen fixation, phosphate solubilization, phytohormone production, siderophore production and antagonistic activity. A pot culture experiment was conducted at the dept of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore. The results revealed that combined inoculation of A. lipoferum - AAs-11, Azotobacter - AAz-3, Bacillus - APb-1 and Pseudomonas fluorescens - APs-1 enhanced the biochemical constituents of ashwagandha such as chlorophyll, protein and total alkaloid contents, especially Withaferin-A.