Abstract Rose (Rosa hybrida) is one of the most important ornamental plants in the world, an‎d its sustainable production under conditions of limited water resources an‎d increasing costs of chemical inputs requires the use of efficient biological solutions. In this study, in order to investigate the effect of different levels of plant growth-promoting bacteria an‎d nutrition on yield, quality, an‎d water an‎d fertilizer use efficiency in branched cluster rose, an experiment was conducted in a soilless cultivation system an‎d as a split factorial in a completely ran‎domized design. The treatments included two different cluster rose cultivars, "Tanja" an‎d "Shine", inoculation with Pseudomonas brassicacearum NBT507 an‎d Enterobacter xiangfangensis NBT508 bacteria individually an‎d in combination, along with two different levels of solution with flow rates of 0.5 an‎d 0.7 liters per hour. Morphological, physiological an‎d post-harvest traits including flowering stem height, number of flowers, chlorophyll, tissue element concentration, photosynthesis, stomatal conductance, water use efficiency, stomatal characteristics, ethylene production an‎d post-harvest life were measured. The results showed that inoculation of plants with growth-promoting bacteria, especially in the combined treatment of two bacteria, caused a significant increase in vegetative growth, physiological indices an‎d flower yield compared to the control. The results of the study showed that inoculation with growth-promoting bacteria increased the number of florets by 21.42% compared to the control. The highest average water use efficiency was obtained in the double bacterial inoculation treatment, which showed a 35.68% increase compared to the control without inoculation an‎d a 32.56% increase compared to the deficit irrigation treatment alone. Iron, which is a key element in cut flowers, increased by 35.77% with double bacterial inoculation, an‎d the use of these growth-promoting bacteria significantly reduced ethylene production an‎d ultimately increased post-harvest life. Also, the use of bacteria under irrigation an‎d limited nutrition conditions was able to significantly increase water an‎d fertilizer use efficiency, such that reducing inputs did not negatively affect yield. Overall, the results of this study indicate that the simultaneous use of Pseudomonas an‎d Enterobacter bacteria can be a biological an‎d sustainable approach to nutrition an‎d irrigation management, improving yield an‎d saving resources in rose production in soilless cultivation systems. Key Words Cut rose, Deficit irrigation, Plant growth-promoting bacteria, Soilless culture, Water use efficiency

علي نيكبخت

مهدي قيصري , محمدرضا سبزعليان دستجردي

مهدي شريفاني , صادق زارعي