Alleviating Effect of Exogenous Application of Ascorbic Acid on Growth and Mineral Nutrients in Cadmium Stressed Barley (Hordeum vulgare) Seedlings

An experiment was carried out in sand-filled pots under normal temperature (28±2ºC) to assess the role of exogenously applied ascorbic acid in alleviating the effect of cadmium (Cd) stress on four barley (Hordeum vulgare L.) genotypes (Jau-83, Jau-87, Paidar 91 and Haider 93).After germination, seedlings were exposed to different Cd concentrations (0, 100, 300, 500 and 700 µM CdCl2) along with AsA (200 mg L -1 ) and grown for 15 days.The results suggested that exposure to increased Cd levels caused a significant reduction in growth and mineral nutrients contents of barley seedlings.However, there was a noticeable difference in the effect of Cd on mineral concentrations among genotypes and the difference mainly coincided with differential accumulation of Cd in the shoot and root tissues.When AsA was applied to Cd-stressed plants, it decreased Cd accumulation in shoots and roots and also showed partial reversal of Cd stress effects.It was also observed that at the same Cd concentrations Cd tolerance index of Jau-83 was the highest among the four barley genotypes, indicating that Jau-83 had lower Cd contents in roots may be more tolerant to Cd stress.The application of AsA was effective in reducing the toxicity of increased Cd by reducing the root or shoots Cd contents, as well as by improving the seedling growth attributes and the mineral nutrients in barley.