Salicylic Acid Induced Salinity Tolerance in Maize (zea Mays)

Salicylic acid (SA) a naturally occurring plant hormone is an essential signal molecule recognized to have diverse effects on biotic and abiotic stress tolerance. The present study was planned to investigate the role of SA in salt tolerance of maize. Experiment was conducted to study the SA induce physiological and biochemical changes in two genotypes of maize viz., Sahiwal-2002 and EV-20 in the presence and absence of salt. Salicylic acid @ 0, 0.25 and 0.50 mM along with 120 mM NaCl and Hogland's nutrient solution were applied as rooting medium to 25 days old plants. Results revealed that application of 0.50 mM salicylic acid was most effective to reduce Na but increased K and Ca concentration, shoot biomass as well as better yield under salt stress. Exogenous application of different concentrations of SA enhanced photosynthetic rate, transpiration rate, stomatal conductance, sub-stomatal CO2 concentration, chlorophyll b contents and carotenoids in both genotypes of maize under salt stress. In conclusion, the level of 0.50 mM SA by rooting medium was more effective as compared to 0.25 mM level on growth, gas exchange characteristics, biochemical attributes and yield. Maize genotype Sahiwal-2002 perform better by increasing higher biomass, better gas exchange characteristics as well as higher K/Na and Ca/Na ratios under salt stress.