Mohammad Hadi Tardasti; Mehdi Madandoust
Abstract
Objective: In order to investigate the feasibility of phytoremediation of cadmium nitrate-contaminated growth substrates with weeds, a factorial experiment was conducted in the form of a completely randomized design in the spring of 2021-22.Methods: The experimental factors included weeds (Portulaca oleracea, ...
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Objective: In order to investigate the feasibility of phytoremediation of cadmium nitrate-contaminated growth substrates with weeds, a factorial experiment was conducted in the form of a completely randomized design in the spring of 2021-22.Methods: The experimental factors included weeds (Portulaca oleracea, Chenopodium album, and Amaranthus retroflexus) and the gowth substrate contamination with cadmium nitrate comprising levels of zero (control), 25, 50, and 75 miligrams per kilogram of soil.Results: The results showed that with increasing consumption of cadmium nitrate, the amount of cadmium in the shoots, roots and biological factors exhibited an increasing trend. The amount of root cadmium was higher in P.oleracea, but the concnetration of shoot cadmium in Ch.album and A.retroflexus showed a significant increase compared to that of P.oleracea. Therefore, in purslane, the transfer of cadmium from the roots to the shoots was probably less than that of Ch.album and A.retroflexus. With the increase in cadmium nitrate concentration, ion leakage displayed an increasing trend, and leaf relative water content and chlorophyll content displayed declining trends. On the other hand, the catalase and ascorbate peroxidase enzymes in leaves showed an increasing trend with increasing cadmium nitrate consumption. Also, the highest activity of antioxidant enzymes was observed in A.retroflexus weeds.Conclusion: Generally, with the mentioned characteristics, ther P.oleracea plant can be considered as a hyperaccumulator, and Ch.album and A.retroflexus can be considered as moderate accumulators of cadmium metal.
Fatemeh Delavarnia; Faezeh Zaefarian; roghayeh hasanpour; Hemmatollah Pirdashti
Abstract
In order to evaluate the ability of forage sorghum (Sorghum bicolor L.) to remediate the heavy metal cadmium with biochar and Pseudomonas putida, a factorial experiment has been conducted based on completely randomized design accomplished in greenhouse conditions with four replications at Sari Agricultural ...
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In order to evaluate the ability of forage sorghum (Sorghum bicolor L.) to remediate the heavy metal cadmium with biochar and Pseudomonas putida, a factorial experiment has been conducted based on completely randomized design accomplished in greenhouse conditions with four replications at Sari Agricultural Sciences and Natural Resources University, in the summer of 2019. Results show that the presence of cadmium in the medium of sorghum reduce the dry weight of root and shoot. However, adding biochar and bacterial inoculation significantly increase the mentioned traits. Bioconcentration factor and bioaccumulation factor have increased from 25 to 100 mg of cadmium, when the highest shoot bioaccumulation factor (2.31) is observed at a concentration of 100 mg Cd per kg soil and in the simultaneous application of Biochar and Pseudomonas putida, which is a significant increase of 28.33% compared to the control. The lowest translocation factor of sorghum (1.000) is related to non-application of biochar, non-inoculation of Pseudomonas putida and without cadmium contamination, itslef reduced by 20% compared to the control, while the highest translocation factor (1.94) is observed at a concentration of 25 mg of cadmium per kg of soil and treatment of non-application of biochar and non-inoculation of Pseudomonas putida. Plant tolerance index has decreased by increasing cadmium concentration, while the use of biochar and inoculation of Pseudomonas putida has increased this index when the highest tolerance index (1.22) is related to the treatment of combined use of biochar and bacteria with no cadmium, increased by 22% compared to non-application of biochar and non-inoculation bacteria. As the tolerance index of forage sorghum in all concentrations of cadmium is more than 0.60, this plant can be classified in the highly-tolerant group to the heavy metal cadmium stress and sorghum could be used for cadmium phytoremediation.