EFFECTS OF CADMIUM ON SEED GERMINATION AND GROWTH CHARACTERS OF Brassica napus L.

Cadmium as a heavy metal has attracted many attentions for its contaminating influences on the environment in the recent decades. This poisonous element, in a high level, can be accumulated in soil through cadmium wastes deposited in river flows. However, plant metabolism would be affected only in high accumulating levels of cadmium compounds. Small growth, decrease in root length and young leave’s chlorosis are among the adverse effects of the element on cadmium treated plants. In this study, seeds of Brassica napus L. were treated with 10, 30, 50, 70, 90, 110, 130, 150 and 200 µM concentrations of cadmium powder. Seeds treated only with distilled water were considered as control group. Germination percent (GP), germination rate (GR), relative germination percent (RGP), mean germination time (MGT), vigor index (VI), germination index (GI), Weighted germination index (WGI) and response index (RI), seedling growth including radicle length (RL), plummule length (PL), seedling fresh weight (SFW) and seedling dry water (SDW), were calculated within a week. Generally, GP and GR decreased with increasing cadmium concentration. The highest decrease in RL and PL was observed in 200 µM.