THE EFFECTS OF GIBBERELLIC ACID (GA3) TREATMENTS ON GERMINATION AND SEEDLING DEVELOPMENT ON SORGHUM PLANT (Sorghum bicolor (L.) Moench) UNDER DIFFERENT SALT CONCENTRATIONS

The study was planned to determine the effects of seed treatments with GA3 on germination and seedling development of sorghum in salinity conditions. The experiment was carried out in petri dishes in the germination cabinet in order to determine the most appropriate concentration of GA3 to eliminate or alleviate the negative effects of salt stress. In this study Rox cultivar belong to sorghum species, obtained from West Mediterranean Agricultural Research Center (BATEM) was used as the plant material. In the study, the seeds were treated with 4 different GA3 concentrations (distilled water-control, 100, 200, 300 ppm GA3) for 24 hours and then germinated at 5 different salt concentrations (distilled water-control, 2500, 5000, 7500, 10000 ppm NaCl). The experiment was established as randomized split plot design with 3 replications. In the study germination rate, mean germination time, shoot and root length, shoot and root fresh weights and shoot and root dry weights of sorghum were investigated. According to the analysis of variance, the effect of the treatments on germination rate was not statistically significant. In addition, salt concentration and GA3 application were significant on all other parameters statistically. Although the salt concentration x GA3 interaction effect was insignificant, there were significant differences amongst the means in Tukey test. It was determined that increased salt concentration had a negative effect on all properties except germination rate. In GA3 treatments, it was determined that 200 and 300 ppm GA3 applications alleviated the adverse effects of salinity on mean germination time and shoot lenght. However, GA3 applications could not mitigate the adverse effects of salinity on the other examined traits.