The Effect of Indole Acetic Acid on Some Growth Parameters of Bread Wheat (Triticum aestivum L. cv. Sagittario) Under Salinity Stress

Salinity is an important abiotic factor that affects plant life quality. Indole acetic acid is one of the most important hormones that affect growth and development in plants and promotes vegetative growth. Wheat, which is the plant material of this study, is basic crop mostly grown in a lot of countries. The aim of this study was to research the effects of salt (125 mM) and different concentrations (2.5, 5 and 25 ppm) on some growth parameters of bread wheat, which grow under the controlled conditions. For this purpose, wheat seeds imbibed in distilled water (as control) and different indole acetic acid solutions and germinated in Petri dishes. The dishes were watered with 0- 125 mM NaCl solutions and harvested five days later. Growth parameters of seedlings (shoot and root length, fresh and dry weight) were recorded and data were evaluated with LSD test. The salinity had negative effect on wheat’s examined some growth parameters (shoot-root length, dry weights) significantly. In addition to these, 25 ppm indole acetic acid decreased these parameters, too; but these findings not found significant. 5 ppm indole acetic acid, slightly ameliorated salinity’s damaging effect. As a result of this study, 125 mM salt concentration had negative effects on wheat seedlings. Although indole acetic acid is a plant growth regulator, the high concentrations of it may cause negative results. Nevertheless, 5 ppm indole acetic acid concentration, positive effects on wheat seedlings slightly against salinity. In conclusion, plant growth regulators may be used by farmers to protect from salinity stress