عنوان مقاله [English]
Background and Objectives:With the progressive increase in industrial and agricultural activities leading to increase in pollutants, soil has received attention as an environmental component and recipient of many of these contaminants.Due to the direct relationship among soil, plants, and humans, pollution in one area may strongly have a negative impact on another.Heavy metals are considered as one type of soil pollutants that can enter the food chain in several ways.Cadmium (Cd) is a heavy metal that has particular importance among the others because it is easily absorbed by plants and causes toxicity.Its detrimental effects on the plant are higher than the other heavy metals.It is crucial to study the uptake and transfer of Cd in the cultivars of wheat which accumulate less amount of Cd.This study aimed to compare the susceptibility of different bread (Triticum aestivum) and durum (Triticum turgidum L.var.durum) wheat cultivars to absorb Cd in Cd-spiked soil.
Materials and Methods:This study was conducted to investigate the effect of different levels of soil Cd (0 and 10 mg kg-1) on its concentration in the roots and shoots of four cultivars (Sirvan, Rakhshan, Talaei, and Parsi) of spring bread wheat and five cultivars (Behrang, Hana, Aran, Shabrang, and Sana) of spring durum wheat.The experiment was set up in a completely randomized factorial design with three replications as a pot experiment in the research greenhouse of the Faculty of Agriculture, Ferdowsi University of Mashhad.After harvesting, to determine the soil total concentration of Cd was used Aqua Regia method.The amount of cadmium in plant organs was also measured by the wet digestion method (nitric acid and hydrogen peroxide).The translocation and biological accumulation factor were calculated for cultivars of both species.
Results:Based on the results, the application of different levels of soil Cd had statistically significant increasing effect on the concentration of this element in roots and shoots of the study wheat cultivars (P<0.01).The Cd concentration in root was estimated more than shoot Cd levels in both wheat species.Among bread wheat cultivars, the most and lowest shoot Cd content was observed in Sirvan and Rakhshan, respectively.On the other hand, in Rakhshan and Talaei were calculated the most and lowest root Cd content, respectively.According to the Cd levels in aerial organs, translocation, and biological accumulation factor, Sirvan had high ability to accumulate cadmium and Rakhshan was more efficient in absorbing cadmium than other cultivars and stored and transported the least amount of this element.Furthermore, according to the information obtained, among durum wheat cultivars, Sana tended to have the lowest Cd concentration of shoot and Behrang tended to have the highest content.In contrast, the highest and lowest amount of Cd in root was related to Sana and Hana, respectively.According to translocation and biological accumulation factor, Sana had less ability to accumulate Cd rather than durum cultivars and Behrang had the highest amount of translocation factors and absorption of this element. Parsi from bread species and Shabrang from durum species had the highest dry weight of shoot in both Cd0 (Control sample) and Cd10 (10 mg kg-1) treatments.In general, bread wheat accumulated a higher amount of Cd in root and shoot than durum wheat.
Conclusion:In general, the concentration of Cd in the shoots and roots of both bread and durum wheat species, as well as different their cultivars, was influenced by Cd-spiked soil.Transfer of cadmium from soil and root to aerial organs was an effective factor in the accumulation of this element in plants.According to the results, each wheat cultivar had different abilities to absorb and translocate Cd.Moreover, for the identification of permissible exposure limits of Cd in soil and wheat, some standards should be considered.