EFFECT OF MANGANESE AND CHROMIUM TOXICITY ON GROWTH AND PHOTOSYNTHETIC PIGMENTS OF MAIZE

Most of the wastes are originated from industries; these wastes include heavy metals, organic and non metallic ions. Soil pollution becomes a coMon issue due to anthropogenic activities. Heavy metals such as lead, chromium, manganese and cadmium are coMon environmental pollutants in those areas where anthropogenic pressure is high. Accumulation of heavy metals in agricultural areas effects crop growth and activity of soil organisms. Heavy metals affect metabolic activities of plants and spread due to the air, water and soil pollution. The main purpose of this study is to evaluate the toxicity of Mn and Cr on growth related traits of maize genotype white corn and to investigate that either maize genotype is more tolerant or more sensitive varieties for metal stress. Study was conducted in physiology lab in IMBB, the University of Lahore during suMer season. Mn and Cr (0, 0.25M, 0.50M) were applied on white corn separately and in combined form and data were collected at different growth stages. Analysis of variance indicated that there was significant difference among 9 different treatments for all parameters except fresh stem weight and fresh root weight and tukey’s test indicated that high toxic affect was observed under  treatment 0.5M MnCl2+0.5M CrCl3  and less toxic affect was observed under  treatment 0.25M MnCl2 + 0.5M CrCl3. But in the case of photosynthetic pigments treatment 0.5M CrCl3 and treatment 0.25M MnCl2+0.25M CrCl3 highly affected but treatment 0.25M MnCl2 and treatment 0.25M CrCl3 were less affected. Therefore maize genotype may be used for phytoremediation in future because it showed resistance against Cr and Mn stress.