Evaluation of Relative Membrane Permeability of Sorghum (Sorghum bicolor) Affected Super Absorbent Polymer and Water Deficit Conditions

Sorghum is among the most important forages used in arid and semi-arid regions of south-eastern Iran. Application of some materials such as super absorbent polymer (SAP) in soil can increase soil water storage capacity and increase water use efficiency. The aim of the study was to estimate the relative membrane permeability of sorghum under irrigation regimes and superabsorbent polymer application to find the relationship between antioxidant enzymes, leaf rolling index, compatible solutes with relative membrane permeability. This experiment was conducted in Dashtak region of Zahedan during 2016 and 2017 growing seasons. The research was arranged as split plot experiment based on randomized complete blocks design with three replications. The main factor included four levels of irrigation regime (40, 60, 80, and 100% of ETc or crop evapotranspiration) and four level of SAP application (0, 75, 150 and 225 kg.ha-1) belonged to subplots. Analysis of regression indicates ascorbate peroxidase, catalase, superoxide dismutase, glutathione peroxidase, proline, glycine betaine, soluble sugars, leaf rolling index and relative membrane permeability showed that by increasing amount of irrigation and superabsorbent polymer, decreased. The results showed that application of SAP reduced RMP by 4.98% under 100% ETc, but it increased the RMP (Relative Membrane Permeability) significantly by 14.14%, 12.18% and 11.48% under 80, 60 and 100% ETc.