| 引用本文: | 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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| 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 |
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李乐乐1, 李中阳2, 吴大付1, 李宝贵2, 樊涛2, 胡超2, 赵志娟2, 刘源2
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1.河南科技学院;2.中国农业科学院农田灌溉研究所
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| 摘要: |
| 【目的】分析不同外源物质对不同品种冬小麦苗期Cd吸收和迁移特征的影响及其差异性。【方法】在含不同浓度Cd（10、30 mg?L-1）的营养液中添加不同浓度的Si、Ca、Mg和腐殖酸，水培条件下研究籽粒Cd高积累百农419和低积累百农418小麦苗期植株Cd吸收和转运特征、植株对Ca和Mg的吸收以及根系形态指标的变化。【结果】不同品种冬小麦对Cd的吸收存在差异。随着营养液中Cd浓度的升高，不同品种冬小麦根系生长受抑制程度更严重。与百农418相比，百农419是喜Ca品种。在低Cd浓度时，与CK相比，低Si添加改善百农419根系生长和降低植株Cd含量效果最好，但其他物质添加抑制了其根系生长且高浓度腐殖酸处理增加了根系中Cd的累积，同时所有外源物质添加均降低了其根系Ca含量；对于百农418来说，加Si和Ca可以促进根系生长且低Si效果最明显，加Mg和腐殖酸对根系生长影响不明显，加Si显著降低了根系和茎叶Cd含量，加Ca和Mg只显著降低了根系Cd含量，加腐殖酸对植株Cd含量无显著影响。在高Cd浓度时，添加Si可以促进两种小麦根系生长并降低根系和茎叶Cd含量，其中低Si和高Si分别对百农419和418根系生长促进效果更好；而其他外源物质添加对Cd毒害基本无明显缓解效果。与其他处理相比，低浓度Cd条件下高Si显著增加了两小麦品种的Cd转运系数，高浓度Cd条件下高Si显著增加了百农419的Cd转运系数。【结论】相比其他外源物质，添加Si对冬小麦Cd毒害缓解效果最明显，且品种、Cd浓度和Si添加浓度交互作用明显。 |
| 关键词: 小麦；硅；钙；镁；腐殖酸 |
| DOI： |
| 分类号:X703.5? |
| 基金项目:十三五国家重点研发计划(2017YFD0801103-2)；中国农业科学院基本科研业务费专项所级统筹项目(FIRI2016-14)；中国农业科学院基本科研业务费专项院级统筹项目(Y2016XT02)；国家自然科学基金青年科学(41701265) |
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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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