Effect of the Pseudomonas Putida Inoculation in Alleviation of Saline Soil Cadmium Stress on Spinach Plant
Increasing cadmium(Cd) accumulation in soil deteriorates cultivated soils, decreases the growth and yield of plants, and enters into the food chain and toxicity. Therefore, the main objectives in this research were to evaluate three levels of Cd in a natural saline soil with and without Pseudomonas putida (PTCC 1696) on the growth parameters of spinach plant. In pots, 3 kg saline soil (ECe: 9.51 dS.m−1) were added.Pseudomonas putida (inoculation and no inoculation) were applied to soil and spinach seeds (Spinaciaoleracea L.) were sown in saline soil of all pots. Soils were treated with three levels of Cd (0, 2 and 4 mg. kg-1).The pots were arranged in a completely randomized design in a greenhouse. After 90 days of planting, chlorophyll a (Chl a), chlorophyll b (Chlb) and proline inleaf samples were determined while the roots and shoots fresh and dry weights and Cd concentrations in spinach were determined100 days after sowing. The results showed that inoculated soils, produced plants with higher Chla, Chlb, and roots and shoots fresh and dry weights were also significantly higher perhaps due to improved nutrients uptake from the stressed soil. At the same time,proline and total Cd concentrations in the roots and shoots were reduced probably due to efficient nutrient uptake even when Cd was present. The addition of Pseudomonas putida to saline soil, remediate the growing plants under salinity stress, also when soil polluted with Cd, the addition of Pseudomonas putida remediate the growing plants under Cd stress. In our study, when soil salinity polluted with different Cd levels combined with microorganism (Pseudomonas putida), our results ensured a more efficient clean-up of Cd polluted saline soil. In conclusion, the Pseudomonas putida (PTCC 1696) inoculation under Cd polluted saline soil, compared to non-inoculated soil, efficiently increased quality and quantity of spinach plant, had better establishment and increased soil health against stresses.