Effect of Gibberellic acid (GA3) on quality and quantity characteristics of sweet violet (Viola odorata L.) flower

Sweet violet (Viola odorata L.) is a perennial plant belonging to the Violaceae family that is not only known as a medicinal and ornamental plant but also widely used in the cosmetics industry. In order to investigate the effect of different concentrations of gibberellic acid (GA3) on the quantitative and qualitative properties of sweet violet flowers, an experiment was conducted in a randomized complete block design (CRD) with three replications at Islamic Azad University of Khorasgan (Isfahan). Treatments were different levels of gibberellic acid (GA3) with three concentrations of 0 (control), 200 and 400 mg/L. Results showed that the application of  gibberellic acid at 400 ppm significantly increased flower number, flower diameter, flowering duration, anthocyanin content, flavonoids, chlorophyll and UV absorptions compared to control treatment. There was no significant difference in terms of anthocyanin, chlorophyll b and carotenoids between the treatment of 200 ppm  gibberellic acid  and control. Flower diameter, flower number, flowering duration and anthocyanin content of flowers at two concentrations of hormone (200 and 400 ppm) showed similar results. Regarding the medicinal use of sweet violet flowers, it is recommended to use hormonal treatments to increase the number of flowers and secondary metabolites of this plant.