SEED GERMINATION AND EARLY SEEDLING DEVELOPMENT OF MAIZE (Zea mays L.) UNDER THE STRESS OF DIFFERENT HEAVY METAL CONCENTRATIONS

Since the lifecycle of plants begins with the germination phase, evaluating this process under different environmental factors may reveal some parameters with great importance for the further development of plants. Also, it can represent a base for other studies. The purpose of this paper was the evaluation of germination and seedling growth of maize under different levels of heavy metal contaminations. The following heavy metals were used as mixtures: Ca, Cu, Ni, Pb, Co and Zn. Five mixtures with different concentrations of Cd (3 to 20 ppm). Cu (20 to 200 ppm). Ni (25 to 200 ppm), Pb (30 to 150 ppm), Co (20 to 100 ppm) and Zn (100 to 700 ppm) were used as variants. and distilled water as control variant. Seed germination percentage was determined in accordance to ISTA (International Seed Testing Association). A series of physiological indicators associated with germination and seedling growth were calculated The germination was observed for ten days, until no changes occurred for three consecutive days. Several effects were observed at the end of the experiment regarding the seed germination and especially to seedling development. Although there were some differences on germination between control variant and high contaminated variants. the growth of seedlings showed a high variation as the concentration of heavy metals increased.