Aluminium (Al) toxicity is one of the primary constraints for plant growth, development, yield and photosynthesis process. It has been demonstrated that mycorrhizae play an important role for survival and growth of plant in acidic soil. In the present study we hypothesized that co-inoculation of mycorrhizae and PGPR would enhance photosynthetic activities of plant in Al toxic soil. The groundnut (Arachis hypogaea L. cv. Girnar-3) seeds were grown in plastic pots filled with vermiculite irrigated regularly with or without aqueous solution of AlCl3 (0, 50, 250, 500 and 1000µM at pH 4.5) in combination with mycorrhizal strain, Glomusetunicatum and Pseudomonas putida species as a PGPR. The effects of these treatments were studied on 25 day old seedlings. The chlorophyll content, carotenoid content, maximal PSII quantum yield (Fv/Fm) and leaf gas exchange measurement viz net photosynthetic rate (Pn), transpiration rate (E), intercellular CO2 concentration (Ci) and stomatal conductance (gs) were analysed. A significant decrease in all these photosynthetic parameters was recorded in groundnut seedlings with an increase in Al concentration. Co-inoculation of mycorrhiza and PGPR showed significant positive impact to ameliorate Al stress through enhancing the chlorophyll content and efficiency of photosynthetic parameters.
