Effect of Trinexapac-Ethyl Growth Inhibitor and Drought Stress on Some Morpho-Physiological Traits of Wheatgrass (Agropyron cristatum L.)

The wheatgrass (Agropyron cristatum L.), is a plant with potential source of turf in arid and semi-arid regions. It can be also cultivated in order to prevent the soil erosion by coverage of earth's surface. Drought stress is one of the most important factors that influence growth and productivity of plants in arid and semi-arid condition. In order to evaluate the effect of trinexapac ethyl concentrations (0, 0.25 and 0.5 kg/h) and drought stress (25, 50 and 75% of field capacity) treatments on some wheatgrass morphological traits, a pot experiment was conducted as factorial in completely randomized block designs with four replications in research greenhouses of Islamic Azad University, Isfahan (Khorasgan) Branch during 2015. The results showed that the maximum plant height and the lowest amount of proline obtained in 75% drought stress treatment. The lowest fresh weight of the aerial parts and the relative water content (RWC) were observed in 25% drought stress treatment. The highest dry weight of the shoots was measured in control, 0.25 kg/h trinexapac-ethyl and 75% drought stress treatments. The highest proline content and the lowest height of the plants were observed in 25% drought treatment with 0.5 kg/h oftrinexapac-ethyl. In general, the research results indicated that under drought stress condition, application of trinexapac-ethyl by increasing the amount of proline and relative water content reduced stress damage and increased resistance to drought stress in the wheatgrass.