Accumulation potential and tolerance to Cadmium pollution and the effect of Silicon on some physiological indices of Portulaca oleracea

Cadmium (Cd) is a heavy metal and the extra concentration of Cd around the root create metabolic problems in the plant. To study the effect of silicon on the availability of Cd accumulation in roots and shoots of morphological and physiological effects on the Portulaca oleracea, a factorial experiment in a completely randomized design with three replications was conducted in the research greenhouse, University of Zabol. The experimental factors consisted of different concentrations of cadmium (0, 20, 40 and 60 mg Cd kg soil) and two levels of silica (without silicon and with Sodium Sellick (1/20 mg/kg soil), respectively. The results showed that the plant height, number of lateral shoots, leaves and root dry weight and the amount of photosynthetic pigments, at concentrations of 20 Cd had no significant with control (p≤%5), but with increasing the concentration of Cd, was observed in the above mentioned factors. Amount of carotenoeid and proline increased by increasing Cd content up to 20 mg.kg-1 over the control. Applying silicon significant positive effect on the main stem height, number of lateral shoots, leaves and root dry weight and levels of photosynthetic pigments (p≤%5). In the plant exposed to silicon the amount of biomass was significantly increased compared to control %5 at level. The amount of biomass declined with increasing the concentration of Cd. However, it is understood that a positive effect on the treatment silicon can increase strength and improve the indices of heavy metal cadmium.