Effect of Plant Growth-Promoting Microorganisms Inoculation on some Growth and Physiological Parameters and Nutrients Content of Sage (Salvia officinalis) Under Salinity Stress Conditions

To evaluate the effect of Piriformospora indica and Pseudomonas fluorescens inoculation on some growth and physiological parameters and nutrient acquisition of sage (Salvia officinalis) under salt stress conditions, a pot experiment was conducted in factorial based on randomized complete blocks design with three replications. The treatments included inoculation with microorganisms at three levels (non-inoculation and inoculation with P. indica and P. fluorescens) and salinity stress at four levels (0, 25, 50 and 100 mM of NaCl). The results showed that salinity stress and inoculation with microorganisms had significant effect on the measured parameters, so that by increasing salinity concentration, percentage of root colonization by P. indica,growth paramaters, leaf relative water content (RWC), chlorophyll index (SPAD), essential oil conten and yield, N, P and K content and K/Na ratio decreased while Na and Cl content increased. The amounts of all evaluated parameters in fungi and rhizobacteria inoculation were more than non-inoculation treatments except for Na and Cl content. The highest and lowest of dry herb yield (29.61 and 13.51 g pot-1), RWC (82.45 and 54.83%), chlorophyll content (35.36 and 26.1), essential oil content (2.02 and 1.37%), essential oil yield (0.049 and 0.017 ml plant-1) and P content (0.41 and 0.10%) were observed in non-stress conditions+ P. indica inoculated plants and 100 mM salinity+ non-inoculated plants, respectively. Overall, the findings of this study showed that plant growth-promoting microorganisms inoculation can ameliorate the adverse effects of salinity stress on growth, yield and essential oil production in sage by maintaining chlorophyll content and improving water and nutrient uptake.