EFFECT OF COBALT AND NICKEL ON GROWTH AND SOME PHYSIOLOGICAL ASPECTS OF MINT (Mentha spicata)
HUSSEIN SABER MOHAMMED ALI AL-RASHEDY *
Department of Biology, College of Education for Pure Sciences, University of Mosul, Mosul, Iraq
*Author to whom correspondence should be addressed.
Abstract
The aim of this study was to investigate the effect of heavy elements (cobalt and nickel) on the growth and some physiological processes aspects of mint (Mentha spicata). We first tested two different concentrations 30 and 60 mg / kg soil from both cobalt and nickel. The experiments and measurements were performed in the laboratory and greenhouses. The current study found that 60 mg / kg soil from cobalt has the most impacts by decreasing the length of shoots and roots to (14cm) and (10) cm respectively. It also changed water to content to (87.87) % and decreased the concentration of potassium in shoots and roots to (21.6) and (12.8) mg / g respectively. However, 60 mg / kg soil from cobalt remarkably increased proline concentration, to (0.0632) µg / g fresh weight compared to the control. The recent work demonstrated that nickel has also a clear effect by decreasing the leaf area to (1.357) cm2, the concentration of chlorophyll a to (0.580) and chlorophyll b to (0.137) mg / g, decreasing the concentration of sodium in the shoot and roots to (2.3) and (4.8). mg / g respectively all compared to the control treatment.
Keywords: Mentha spicata, cobalt, nickel, chlorophyll.