Tallapragada, SrideviMehra, Indu2024-03-272024-03-272023-09https://krishikosh.egranth.ac.in/handle/1/5810207751The present study entitled “Efficacy of gibberellic acid and triacontanol on morpho-physiological, biochemical and anatomy of Sorghum bicolor L. under salt stress,” was examined in the screen house during the kharif season of 2022. Prior to sowing, different salt stress levels (control, 4, 6, and 8 dS m-1) were maintained by saturating each pot. Sorghum bicolor L. seeds were planted in pots under screen house conditions on July 25th, 2022. Triacontanol was applied at concentrations of 10 ppm and 20 ppm, while Gibberellic acid was applied (200 ppm and 400 ppm) to both stressed and non-stressed plants of two genotypes (CSH20MF and CSH24MF). Sampling was conducted at 30 and 60 days after sowing (DAS). Growth parameters were examined. An inverse relationship was observed between these parameters and increasing salinity levels. Furthermore, anatomical leaf characteristics were improved following the application of Triacontanol and Gibberellic acid, counteracting the negative effects of salt stress. A similar pattern was observed in the relative water content under different salt levels. Total chlorophyll content, carotenoid content, gaseous exchange studies, chlorophyll index, and photochemical quantum yield also displayed a decreasing trend from the control to the highest salt level (8 dS m-1) in both genotypes. The application of Triacontanol and Gibberellic acid aids in maintaining the relative water content, increasing proline and glycine betaine content, enhancing gas exchange, ash content, chlorophyll index, total chlorophyll, carotenoid content, anthocyanin, flavonoid content, and promoting the activity of antioxidant enzymes regardless of salt stress in both genotypes. Conversely, the relative stress injury worsens with each increment of salt stress, but the application of Triacontanol and Gibberellic acid partially mitigates the adverse effects of salt stress. An increase in Na+ content and a decrease in K+ and Ca2+ content was observed under salt stress, whereas the opposite trend was observed after the application of TRIA and GA3. In sorghum genotypes CSH24MF and CSH20MF performed better under salt stress and exhibited a superior response in alleviating salt stress with the foliar application of 20 ppm of Triacontanol.EnglishThesis