Copper And Zinc Element Toxicity And Tolerance On Seed Germination And Seedling Growth Of Leucaena Leucocephala (Lam) De Wit.

The release of metals due to anthropogenic, industrial and automobile activities brought up changes in nature, structure and composition of the biological communities and high concentration involved in the extinction of plant species. The flora of the region is particularly affected due to constant increase of environmental pollutants such as heavy metals at alarming scale. Therefore, effects of Cu2+, Zn2+ individually and in combinations Cu2+ + Zn2+ on germination and growth of Leucaena leucocephala (Lam.) de Wit. was evaluated in invitro. In this study the treatment of different concentrations (0, 25, 50, 75 and 100 ppm) of copper, zinc individually and in combination showed different effects on rate of seed germination and seedling growth of L. leucocephala. Seedlings growth performance of L. leucocephala gradually reduced with increased in concentrations of Zn, Cu and Cu + Zn as compared to control. The combined metal treatments of Cu + Zn were found more toxic as compared to individual treatment of copper and zinc.Tolerance indices and seedling vigor index of L. leucocephala for individuals and combined metal treatment also decreased with increase in concentration of Cu and Zn in substrate. The lowest reduction in seedling tolerance indices of L. leucocephala was recorded for Cu treatment at 100 ppm as compared to control. This reduction was prominent for Zn treatments.