Effect of foliar spraying of iron nanoparticles on improvement of some physiological and morphological traits of purslane (Portulaca oleracea) under cadmium stress

In order to investigate the effects of foliar spraying of iron nanoparticles on improvement of some physiological and morphological traits of purslane (Portulaca oleracea) under cadmium stress, a factorial experiment was conducted in a completely randomized design with three replications. The experimental factors included cadmium chloride in six levels (0, 25, 50, 75,100 and 125 mg/kg soil) and foliar spring of iron nanoparticles in five levels (0, 0.25, 0.5, 0.75 and 1 g/l). The results showed that The interction effects of iron nanoparticles and cadmium was significant on leaf area, root dry weight and proline content at 5% and leaf dry weight and chlorophyl contents (SPAD number) at 1% probablity level. The leaf area respond a linear decrease trend with increasing cadmium levels at levels of 0, 0.5, 0.75 and 1 g/l of foliar spraying of iron nanoparticles. By contrast, respond it was respond as a segmented model at concentration of 0.25 g/l. Foliar spraying of iron nanoparticles at all four levels increased root dry weight to 25 mg/kg of cadmium, but at levels above 25, the root dry weight decreased at higher level of Cd. Meanwhile, the concentration of 0.5 g/l of foliar spraying of iron nanoparticles had the most effect on root dry weight by 34.80% increase as compared to the control. SPAD value increased in both levels of 0.5 and 0.75 to 25 mg/kg of soil cadmium, 11.19 and 28.99% respectively, as compared to the control. In general, our results, indicated that foliar application of iron nanoparticles was effective to improve cadmium tolerance in purslane plant in low cadmium concentrations. However, more research is needed to investigate the mechanism of iron nanoparticles.