Ecophysiological studies of a pulse crop (Cajanus cajan L.) with zinc sulphate stress

Abstract

The germination data showed that there is direct impact of Zinc sulphate on the germination of seeds. When the plants were exposed to ZnSo₄ stress, at high concentrations   it inhibits seed germination, growth and development of seedlings. At a higher concentration i.e., 100 Mg/L, the seed germination is very less than that of control. Both root and shoot growth of seedlings were badly affected with exposure to high concentration of Zinc sulphate. Roots were highly affected and much more reduced than that of shoots. Morphologically, they looked different from normal roots by their colour, shape and size. Effect of different concentrations of Zinc sulphate was visible in different pigment concentrations of leaves. With increase in concentration of the toxicant exposure to the seeds, a decline in chlorophyll-a, chlorophyll b, total chlorophyll   contents in the shoots were observed. This was a clear indication of decreases in the plant growth rate and pigment contents that had direct impact on photosynthesis. Conclusively, our result showed that Zinc at higher concentration decreases, chl-a, chl-b and total chlorophyll. This results suggests that the presence of Zinc  at higher concentration caused in growth inhibition, a decline in physiological and pigment activities, structural damage etc. However, further research in this regard is required to find out the effects of ZnSO₄  on metabolic activities of different plants.

Keywords: Zinc Sulphate, Pulse, Cajanas, Pigment, Germination