Effect of application of potassium fertilizers on physiological traits and cadmium accumulation in grain of two durum wheat (Triticum turgidum ssp. Durum (Desf.) Husn.) cultivars

Potassium fertilizers affect cadmium uptake and accumulation in plants under cadmium-contaminated soils. To determine the role of potassium in alleviating the adverse effect of cadmium in two durum wheat cultivars (Behrang and Yavaros), an experiment was carried out as factorial in randomized complete block design with three replications in Shahid Chamran university, Ahvaz, Iran in 2012. Experimental treatments included: control, 20 mg Cd kg-1 soil (CdCl2), 20 mg Cd kg-1 soil + two levels of 300 and 450 mg K kg-1 soil as potassium sulphate, and two levels of 30 and 45 mg K kg-1 soil as nano chelate potassium 27%. Cadmium on its own reduced grain yield, biological yield, chlorophyll index, relative water content, stomatal conductance, total chlorophyll content and grain K content in both cultivars (72, 50, 22, 23, 56, 30 and 53%, respectively), but grain Cd content was increased by 13 fold. Potassium application in combination with cadmium, especially in two levels of 30 and 300 mg K as nano chelate potassium and potassium sulphate, respectively, led to mitigating the negative effects caused by cadmium stress on agronomic and physiological traits. Grain cadmium content decreased in these treatemnets when compared with cadmium treatment. In conclusion, these findings showed that potassium plays an important role to improve durum wheat crop growth and reduce grain Cd content.