عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Recently, rhizospheric microorganisms such as arbuscular mycorrhiza fungi (AMF) and plant growth promoting bacteria (PGPR) are in use to increase plant growth and plant tolerance to heavy metals. In this study, the effects of AMF and PGPR inoculation were evaluated on uptake of some elements and physiological properties of Centaurea (Centaurea cyanus) in a Cd contaminated soil. This study carried out in a greenhouse condition as a factorial experiment based on a randomized complete block design with three replications. Four levels of Cd concentrations (0, 250, 500 and 1000 mg kg-1) and three levels of microbial treatments (control, AMF (mixture of Glomus and Rhizophagus speciesincluding R. intraradices, G. mosseae and G. fasciculatum) and PGPR (mixture of Pseudomonas species includeing P. putida, P. fluorescens, and P. aeruginosa)) were included in the study. Results indicated that by increasing Cd concentrations, plant growth, Fe, Cu and Zn concentrations in shoot of Centaurea, chlorophyll and carotenoeids contents, plant height and microbial respiration decreased, while proline content and Cd concentration in shoot and root of Centaurea significantly (p<0.05) increased. Chlorophyll content in AMF and PGPR treatments were respectively 2.2 and 1.3 and carotenoeids contents were 2.4 and 2 times higher than the corresponding control treatments. Micronutrient uptakes in microbial treatments were higher compared to control treatment. Iron, zinc and copper concentrations in microbial treatments were 1.5 times higher than control treatment. It is concluded that microbial inoculation improved the plant growth and enhanced the plant tolerance to Cd toxicity.