Interaction of cadmium tolerant plant growth promoting rhizobacteria and organic amendments to suppress cadmium uptake in tomato.

High cadmium (Cd) concentration in soils is becoming a severe threat to environment. It deteriorates plants growth, yield, and quality of food. Although the use of plant growth-promoting rhizobacteria (PGPR), biochar and compost have been reported environment-friendly amendments for decreasing Cd stress in crop plants, but the impacts of their simultaneous co-application has not been well documented. Thus, current study was carried out to investigate the combined role of cadmium tolerant rhizobacteria, compost and biochar on the growth and Cd uptake in tomato under cadmium stress. Cd tolerant plant growth promoting rhizobacteria (PGPR) were isolated from the rhizosphere of tomato grown on soil irrigated with industrial wastewater (effluents). Based on growth promotion traits and cadmium tolerance, four strains (J62, J156, J159, J165) were selected for conducting trial in growth chamber. Cadmium salt (CdCl2) and organic amendments were applied before transplanting of tomato seedlings and were inoculated with Cd tolerant rhizobacteria. After 4 weeks, plants were harvested for determination of Cd concentration and other parameters of plant. Results showed that cadmium caused reduction in all growth and physiological parameters of tomato. Sole and combined application of Cd tolerant PGPRs and organic amendments increased the growth of tomato and suppressed Cd uptake in tomato. But their interaction was more prominent as compared to sole application of each PGPRs and organic amendments. It was concluded that combined application of PGPR with organic amendments has a greater potential to suppress Cd uptake and improvement in growth of tomato under Cd stress, compared to the alone application of PGPR and organic amendments. Findings will be communicated to policy maker and extension worker for wide field application. [ABSTRACT FROM AUTHOR]