PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

Heavy metal toxicity affects plant growth, human and animal lives, and microbial activity etc. Heavy metals have badly affected the metabolism and physiological activities of different          plants. Heavy metals cannot be destroyed or degraded therefore when their concentration is exceeded they accumulate into the plants and cause toxic effects. Data was conducted to     investigate the effect of heavy metals Cr and Mn toxicity on Zea mays growth and its                 related traits. Total five different seed varieties of Zea mays (30Y87, 31R88, Neelum, Pak          Afghoi and White Corn) were used during investigation. Different concentrations (0, 0.25 M and 0.50 M) of Cr and Mn were prepared. All varieties were treated with Cr and Mn separately and in combined form with the interval of 8 days. Three replications were carried out for each       treatment during research. Data was recorded for different morphological traits in roots,           stems and leaves. Step wise linear regression and person’s correlation were applied as statistical tool among treatment means. Correlation indicated that higher and significant correlation was found for dry leaf weight with dry stem weight, root diameter with leaf area, dry root weight with dry stem weight, stem diameter with plant height, dry stem weight with fresh stem weight, fresh leaf weight with fresh root weight, fresh stem weight with plant height, leaf area with plant height. Regression analysis indicated that there was high and positive contribution of dry leaf weight for plant height. The accumulative medium coefficient of determination (51.77%) or R² was found plant height while high coefficient of determination or R² was found for fresh leaf weight (96.29%).