Interactive effect of chromium and ascorbic acid on germination, growth and mineral nutrition of two maize genotypes

Heavy metal toxicity is one of the major abiotic stresses leading to loss in agriculture yield. Heavy metals are very reactive and directly influence growth because their presence leads to accumulation of reactive oxygen species. Ascorbic acid acts as an antioxidant because it protects the plants against oxidative stress. In present research work interactive effects of ascorbic acid and chromium on two genotypes of maize (Zea mays L.) i.e. (EV-77 and FH-985) were studied. A pot experiment was carried out in the wire house of Old Botanical Garden, Lalazar Colony, University of Agriculture, Faisalabad. The experiment was conducted in completely randomized design with three replicates. Seeds were sown in plastic pots containing thoroughly washed river sand. Hoagland's nutrient solution was applied at the time of sowing. Three days old seedlings were subjected to the chromium (0 muM, 2 muM, 5 muM) and ascorbic acid (0mg, 200mg, 500mg) treatments under the half strength Hoagland's nutrient solution. After the application of treatments data related to different germination, growth and mineral nutrients parameters was recorded and analyzed statistically by using COSTAT computer software packages. Exposure of two maize genotypes to chromium stress severely affected the germination, growth and mineral nutrients parameters. Percentage germination, emergence index, mean emergence time, 50% emergence of seedlings and coefficient of uniformity of emergence as well as growth parameters such as shoot and root length, shoot and root fresh and dry, number of leaves and leaf area per plant were reduced significantly. This study proved that chromium is highly toxic metal that suppressed germination, growth and ion uptake in maize. Ascorbic acid enhances the germination, growth and mineral contents and ameliorated the toxic effect of chromium in studied maize genotypes.