| Cite this article: | 李乐乐,李中阳,吴大付,等.外源物质对镉胁迫下不同品种冬小麦苗期镉吸收特征的影响[J].灌溉排水学报,0,():-. |
| Li Lele,Li Zhongyang,Wu Dafu,et al.外源物质对镉胁迫下不同品种冬小麦苗期镉吸收特征的影响[J].灌溉排水学报,0,():-. |
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| Effects of Different Exogenous Substances on the Cadmium Accumulation in Different Varieties of Winter Wheat at Seedling Stage under Cadmium Stress |
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Li Lele1, Li Zhongyang2, Wu Dafu1, Li Baogui2, Fan Tao2, Hu Chao2, Zhao Zhijuan2, Liu Yuan2,1
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1.Henan Institute of Science and Technology;2.Farmland Irrigation Research Institute,Chinese Academy of Agricultural Sciences
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| Abstract: |
| 【Background】Among toxic elements of global concern, cadmium (Cd), a non-essential element, is one of the priority inorganic contaminants in agricultural soils globally due to its increasing input through wastewater irrigation as well as application of phosphate fertilizers containing Cd impurities, sludges and composts. China is no exception, where Cd ranks the first in the soils polluted with heavy metals and metalloids. Cd is highly toxic to humans and shows high mobility and plant uptake. When the Cd concentration in the crop tissues accumulates to a threshold, it can cause crop growth retardation, yield decline and other symptoms, and even crop death. The World Health Organization (WHO) lists Cd as a key food contaminant, and the International Cancer Research Agency (IARC) recognizes Cd as a Class I carcinogen. Numerous studies have demonstrated that the addition of exogenous substances can alleviate the toxic effects of Cd on crops. However, effects of different exogenous substances on the Cd accumulation in different varieties of winter wheat under different Cd stress were not thoroughly explored. 【Objective】 We aimed to investigate the effects of exogenous Si, Ca, Mg and humic acid on Cd uptake and migration characteristics in different winter wheat varieties at seedling stage. 【Method】 Two varieties of winter wheat, Bainong 419 (419) with high Cd accumulation in grain and Bainong 418 (418) with low Cd accumulation in grain, were cultured in nutrient solution with 10 mg?L-1 or 30 mg?L-1 of Cd and different doses of Si, Ca, Mg and humic acid for 30 days. Cd accumulation and transportation in their roots and shoots as well as the root morphology parameters were studied. 【Results】There was a difference in the absorption of Cd between these two wheat varieties. Total length, surface area, volume, and tip number of roots of these two varieties all decreased with the increase of Cd concentration in the solution. Compared to 418, 419 demanded higher Ca for the normal development of roots. At low-Cd solutions, compared with CK, Si addition especially low dose of Si improved the root growth of 419 and reduced the Cd content in roots and shoots, while the amendment of other substances inhibited its root growth, and high dose of humic acid resulted in the higher accumulation of Cd in roots. Besides, all exogenous substances decreased Ca content in roots of 419 at low-Cd solution relative to CK. As for 418 at low-Cd condition, Si and Ca promoted root growth with the best effect in low dose of Si, but Mg and humic acid did not exert an obvious influence on root growth; Si declined the Cd enrichment in roots and shoots significantly, yet Ca and Mg only lowered the root Cd, humic acid addition did not affect plant Cd significantly. At high-Cd solution, Si facilitated root growth of both varieties, and low dose and high dose presented a better effect on 419 and 418 respectively; however, other substances could not alleviated Cd toxicity to plants remarkably. Compared with other treatments, high Si significantly increased the translocation factor (TF) for both varieties at low-Cd condition, and TF for 419 at high-Cd condition. 【Conclusion】 The best allevation effect of Cd toxicity to winter wheat were observed in Si treatments, which was affected by wheat variety, Cd dose and Si dose as well as their interaction. |
| Key words: wheat; Si; Ca; Mg; humic acid |
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