Morpho-Physiological and Biochemical Attributes of Tall Fescue (Festuca arundinaceaSchreb.) Inoculated with Pseudomonas fluorescensunder Deficit Irrigation

Urban green spaces are a form of land use that often require intensive maintenance and have social and ecological functions. Due to global water scarcity, management strategies regarding planting and maintenance vegetation, especially turfgrass, are changing in many countries. Tall fescue serves as one of the most important and commonly used cool-season turfgrass species and is considered to be drought tolerant. Plant growth-promoting rhizobacteria (PGPR), as bio-fertilizers, are also crucial in terms of decreasing and improving harmful effects of abiotic stresses in plants. This research considers inoculation with PGPR in turfgrass for the purpose of improving drought tolerance and reducing water consumption. This work was conducted over two consecutive years to study the effects of Pseudomonas fluorescenson two cultivars of tall fescue (‘H-d’ and ‘J-r’) with three irrigation intervals (7, 14, and 21 days) under greenhouse and outdoor conditions. Results showed that irrigating less frequently caused a reduction in tall fescue turf quality, fresh weight, chlorophyll content, relative water content, and phosphorus content. In most cases, the quantity of compatible solutes (proline and glycine betaine) and antioxidant enzymes (superoxide dismutase and peroxidase) was increased; however, the rate of change was enhanced in turfgrass treated with PGPR. Quantitative and qualitative characteristics of turfgrass in greenhouse experiment were substantially superior in comparison with outdoor condition. This research is novel, as it is the first quantitative and qualitative study to the best of our knowledge exploring the effect of PGPR on turfgrass biomass. The level of amino acids, the activity rate of antioxidant enzymes, and the bacterium effects on turfgrass have been considered, both under greenhouse conditions and outdoor environment. This research provides a methodology to investigate various beneficial bacteria on turfgrass for the purpose of developing better management programs under stress conditions.