Amelioration of Cadmium Toxicity by Exogenously Applied Salicylic Acid in Two Contrasting Barley Genotypes

The mitigating role of salicylic acid in growth, yield and various yield parameters in barley (Hordeum vulgare), genotypes viz., Jau-83 and Jau-87 under cadmium induced stress was studied. The pot study was carried out in the wire house, University of Sargodha, Lyallpur Campus, Faisalabad. Two (0 and 500 µM) levels of Cd metal and three (0.1, 0.5 0.9 mM) levels of salicylic acid alone and in combinations were applied directly in river sand medium. The experiment was designed as Completely Randomized (CRD), with factorial arrangement. Results revealed a marked reduction in shoot and root length, fresh and dry biomass, number of leaves and total leaf area and shoot root ratio under cadmium stress and increased with salicylic acid, but all the three level of SA behaved differently. Maximum increase in growth parameters were noted at 0.5 mM SA compared to 0.1 and 0.9 mM in both the barley genotypes. Although both genotypes statistically behaved similarly, Jau-83 behaved better than Jau-87. The results of yield provided drastic effect of Cd metal on all the recorded yield and yield parameters. The addition of salicylic acid alone in the irrigation medium increased the yield parameters. The results noted about the mitigating effect of salicylic acid under Cd stress exhibited an increase in yield parameters but the increase was less at low and high level of SA than 0.5 mM. SA suppressed the effect of cadmium induced stress and showed increase in growth and yield and yield parameters when applied exogenously through rooting. Results showed presence of SA in the irrigation medium containing cadmium metal mitigated the toxic effect of cadmium.