Effect of Pb-Stress on Growth and Mineral Status of Two Groundnut (Arachis hypogaea L.) Cultivars

Abstract

Heavy metal pollution of air and agricultural soils is one of the most important ecological problems on world scale. Among the heavy metals, lead (Pb) is one of the common environmental pollutants. To investigate Pb effects on nutrient uptake, two groundnut (Arachis hypogaea L.) cultivars (cultivar K6 and cultivar K9) were grown in pot cultures and stressed with lead nitrate (Pb(NO 3) 2) at four concentrations (100, 200, 400 and 800 ppm). Pb is accumulated in roots and leaf tissues in dose dependent manner in both groundnut cultivars, which resulted in reduced root and shoot growth and lower uptake of all mineral ions tested. The content of mineral ions such as Ca, Na, Mg, Co, Cu, Ni, Zn and Mn reduced in root and leaf tissues of both cultivars due to Pb stress. But the reduction in mineral ion content was less in cultivar K6 than in cultivar K9. The deficiency of mineral nutrients correlates in a strong decrease in the contents of total chlorophyll, and anthocyanin in both cultivars, but these effects are less pronounced in cultivar K6 than in cultivar K9.