عنوان مقاله [English]
The main objective of the current research was to evaluate the effect of Cd concentrations on the growth, uptake of P, Fe, Zn, Cu and Mn of alfalfa plant mycorrhized by Rhizophagus intraradices. A pot culture experiment was performed as completely randomized design by two factors, including AM fungus (inoculated with R. intraradices and non-inoculated) and four levels of Cd (0, 15, 30 and 45 µM Cd+2) with three replications. Shoot and root dry weights of mycorrhizal (M) and non-mycorrhizal (NM) plants were affected by increasing of Cd levels. At the levels of 15, 30 and 45 µM Cd+2 shoot and root dry weights were decreased by 0%, 8.2%, 25% and 9.5%, 16.2%, 39.8% compared to the control (0 µM Cd+2), respectively. Shoot and root dry weights of M plants were increased by 48.7% and 42.8% compared to the NM ones. P contents of shoot and root were affected by AM fungus, so that the shoot and root P contents of M plants were increased by 54.1% and 49.6% compared to the NM ones. Root colonization and mycorrhizal dependency were affected by Cd treatments. At the levels of 15 and 30 µM Cd+2, root colonization and mycorrhizal dependency were increased by 38.2%, 35.7% and 100%, 77% compared to the control, respectively. Maximum Cd contents of shoot and root were recorded at the levels of 15 and 45 µM Cd+2 in M plants which were increased by 81.97% and 71.99% respectively, compared to the NM ones at the same levels. Cd-translocation from root to shoot was decreased as the Cd concentration increased. At the all levels of Cd, the concentrations of Fe, Zn, Cu and Mn were often higher in roots than in shoots. Generally, with increasing Cd concentration, plant uptake of Fe, Zn, Cu and Mn were decreased compared to the control. At the Cd levels, metal translocation from root to shoot were decreased for Fe, Zn and Mn and increased for Cu compared to the control, respectively.