Abstract

Heavy metals play an important role on plant growth and toxicity. The toxicity of heavy metal is a problem of ecological, evolutionary and environmental reasons. Heavy metal toxicity is one of the major abiotic stress leading to hazardous health effects in plants and animals. The most common symptoms of nickel toxicity in plants are inhibition of growth, photosynthesis, mineral nutrition, sugar transport and water relations. The present study investigated the effect of nickel (Ni) on antioxidant potential in maize (Zea mays L.). Ni was applied in the form of NiCl₂ in different concentration (0, 100, 200 and 800 µM) on maize cultivars (919 and 30y87) under controlled condition of light and temperature for four weeks. Seeds of two maize cultivars were obtained from Ayub Agricultural Research Institute, Faisalabad. The experiment was laid out in a completely randomized design (CRD) with four replications. After four weeks of treatments, plants were harvested and various growth parameters were collected. The effect of Ni stress was more prominent on 919 than on 30y87 cultivars. The growth of root was much affected than that of the shoot in both cultivars. When the concentration of nickel increased, the antioxidant potential increased in the variety of 30y87, while in the variety of 919, Ni concentration increased, but the antioxidant potential decreased.  The variety 30y87 showed more resistance towards different Ni concentrations.

Key words: Nickle, maize, antioxidants.