Effects of Some Heavy Metals in Some Morpho-Physiological Parameters in Maize Seedlings

Abstract

Nowadays the heavy-metal pollution of the soil is causing ever greater problems, exacerbated by the fact that the heavy metals accumulated in plants may, either directly or indirectly, find their way into animals and human beings. Maize is one of the world’s most important crops, ranking third after wheat and rice, so the changes induced by one of the most toxic heavy metals. The experiment design was randomly with repetition. Prepared seeds are placed on the germinator for germination which was added 10 mL H₂O. Cultivation lasted 15-20 days at temperature 25°C in vegetative room. During the experiment in growth period are prepared the concentrations of heavy metals (600 mL/1 Kg compost); for lead (Pb²⁺): 200 µM (T1), 400 µM (T2) and 400 µM (T3); for cadmium (Cd²⁺): 60 µM (T4), 120 µM (T5) and 180 µM (T6); for Mercury (Hg²⁺): 33 µM (T7), 66 µM (T8) dhe 100 µM (T9). Elements concentrations of heavy metals (HM’s) solutions include Pb, Cd and Hg, were examined in all (except control) treatments, because their intoxication was at higher doses compare to control and a part of them of residual od HM’s in the substrate was transport in different parts of plants. The plants of maize populations for leaf area was characterized on higher values 40.48 cm² plant^-1 or expressed in percentage the variation was 82.01%. The exposure of maize seedlings to Pb²⁺, Cd²⁺ and Hg²⁺ resulted in a reduction of chlorophyll and carotenoids content in leaves compare to control. From our research with different treatments with various genotype and heavy metals the differences in the content of chlorophyll effects and carotenoides was different and significantly higher at level of probability of LSD p = 0.01.