Eeffect of bacterial inoculation, bacterial exopolysaccharide and nano SiO2 particles on seed germination of Solanum lycopersicum under salinity stress

Salinity is a major abiotic stress which is limiting growth and productivity of plants. Salinity affect plant growth differently in all growth stages. Looking at different mechanisms for increasing plant tolerance has been noticed to overcome the problem of salinity. Present study was designed to evaluate the effects of bacterial inoculation, bacterial exopolysaccharides and nano silicon particles on reducing salinity stress in seed germination of Solanum lycopersicum. This study was carried out in the greenhouse condition in Islamic Azad University of Isfahan. It was done through a completely randomized design with three replications, in February 2016. Treatments were: Exopolysaccharide solution (0.01 M), 1 ml of bacterial suspension (1×108 CFU.ml-1), nano silicon particles (8 g.L-1). Tomato seeds (cultivar PS) were sterilized and inoculated with treatments then planted in pots. Irrigation was carried out during the experiment, with the saline water (0.3, 2, 4, 6, 8 dS.m-1). After 15 days the effect of treatments on germination percentage, germination rate and mean germination time and vigor index were assessed. Based on the results, the effect of treatments at different salinity levels, on the germination percentage, germination rate, vigor index and mean germination time, (0.01 and 0.05 probability levels) was statistically significant. So that germination percentage, germination rate, vigor index were decreased with increasing salinity and mean germination time was increased significantly, while the use of nanoparticles silicon, inoculation of salt tolerant bacteria and bacterial exopolysaccharides reduced the negative effects of salinity on seed germination factors. Seed germination, germination rate, vigor index increased in all treatments and mean germination time reduced significantly under salinity stress.