Journal of Agronomy and Field Innovations

Background: Sorghum bicolor is one of the drought-resistant cereals. It contributes to food and feed security in semi-arid areas but the detrimental impacts of climate change and the consecutive changes in drought characteristics led to declines in productivity. 
Objective: This study was conducted to evaluate the physiological mechanisms of sorghum adaptation to progressive water restriction for the identification of drought-tolerant features. 
Methods: Birds were taking from a pot with four irrigating regimes including 10%, 75%, 50% and 25% of field capacity for 30 days through application of completely randomized block design with four replications. The characteristics of water relations, gas exchange, chlorophyll fluorescence, osmolyte accumulation in tissues, membrane stability, and activities of antioxidant enzymes were measured and analyzed using one-way ANOVA (P < 0.05).
Results: The progressive shortage of water considerably decreased relative water content, leaf water potential, photosynthetic rate, stomatal conductance, and Fv/Fm, while the quantities of proline, soluble sugars, malondialdehyde, hydrogen peroxide and activity of antioxidant enzymes (SOD, CAT, POD, APX) saw a significant improvement under heavy stress compared to properly-watered plants.
Conclusion: Sorghum employs several mechanisms including the regulation of stomatal function, osmotic adjustment, and strengthening antioxidant protection to keep its cells functioning in the conditions of drought, thus offering potential physiological goals in breeding resistant plants and efficient water management in agriculture.