| 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,2021,(1):79-90. |
| 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,2021,(1):79-90. |
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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】通过向含不同质量浓度Cd（10、30 mg/L）的营养液中添加不同质量浓度的Si（28、56 mg/L）、Ca（50、100 mg/L）、Mg（50、100 mg/L）和腐殖酸（5、15 mg/L），在水培条件下研究了籽粒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质量浓度的升高，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质量浓度时，与CK相比，低Si添加改善百农419根系生长和降低植株Cd量的效果最好，但其他物质添加抑制了其根系生长且高质量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量，加Ca和Mg只显著降低了根系Cd量，加腐殖酸对植株Cd量无显著影响。在高Cd质量浓度时，添加Si可以促进2种小麦根系生长并降低根系和茎叶Cd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，低质量浓度Cd条件下高Si显著增加了2种小麦的Cd转运系数，高质量浓度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质量浓度和Si质量浓度交互作用明显。 |
| 关键词: 小麦；硅；镉；钙；镁；腐殖酸 |
| DOI：10.13522/j.cnki.ggps.2019467 |
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| Cadmium Accumulation in Wheat of Different Varieties at Seedling Stage as Impacted by Addition of Exogenous Elements |
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LI Lele, LI Zhongyang, WU Dafu, BAN Zhuohao, LI Baogui, FAN Tao, HU Chao, ZHAO Zhijuan, LIU Yuan
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1. Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang 453002, China; 2. Henan Institute of Science and Technology, Xinxiang 453003, China;3. Changyuan Vocational Secondary Professional School, Xinxiang 453400, China
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| Abstract: |
| 【Background】Cadmium (Cd) is one of contaminants found in agricultural soils caused by anthropogenic activities including wastewater irrigation and application of phosphate fertilizers rich in Cd impurities, sludges and composts. In China, Cd contamination comes to the top in soils contaminated by all heavy metals and their metalloids. Since Cd is toxic to all organisms and highly mobile in soil for plants to take up, excessive Cd accumulation in crop tissues could impede its growth and even lead to mortality. Numerous studies showed that adding exogenous substances to soil could alleviate toxic effects of Cd on crops, but if and how their efficacy varies with crop variety remains poorly understood.【Objective】Taking winter wheat as an example, this paper aimed to investigate the effects of exogenous Si, Ca, Mg and humic acid on uptake of Cd by different cultivars and its subsequent translocation at seedling stage.【Method】 Wheat varieties Bainong 419 (419) with high Cd accumulation in grain and Bainong 418 (418) with low Cd accumulation in grain were taken as the model plants. They were grown in hydroponic culture with the Cd content in it spiked to 10 mg/L or 30 mg/L respectively. We added Si, Ca, Mg and humic acid at different rates to the medium and harvested the crops 30 days later. We then measured Cd accumulation and transportation in roots and shoots, as well as root morphology traits.【Result】Crop absorption of Cd varied with the wheat varieties, and the total length, surface area, volume and tip number of the roots in both varieties decreased with the increase in Cd concentration. Compared to variety 418, variety 419 took more Ca for its root developments. At low Cd concentration and compared to CK, adding Si at low dose improved root growth of the variety 419 and reduced Cd accumulation in its roots and shoots, while adding other elements inhibited root growth; applying humic acid at high dose enhanced Cd accumulation in the roots. It was found that compared to CK, adding any exogenous element reduced Ca content in the roots of the variety 419 when Cd concentration was low. For the variety 418 grown in medium with low Cd concentration, adding Si and Ca was more effective to promote root growth than adding Si alone, while adding Mg and humic acid did not show noticeable effects. Adding Si reduced Cd accumulation in roots and shoots at significant level, while adding Ca and Mg only impeded Cd accumulation in the root. Humic acid did not appear to have a noticeable impact on plant Cd. For the crops growing in medium with high Cd concentration, adding Si boosted root growth of both varieties regardless of its application rate, while in contrast, adding other elements were unable to alleviate Cd toxicity to plants at significant level. Compared with other treatments, adding Si at high does significantly increased the translocation factor (TF) for both varieties growing in medium with low Cd concentration, and it was also effective at boosting the TF for the variety 419 growing in medium with high Cd concentration.【Conclusion】The most effective conditioner to alleviate Cd toxicity to winter wheat was Si, although its efficacy varies with wheat cultivar, Si application rate and Cd concentration in the medium where the crop grows. |
| Key words: winter wheat; Si; Cd; Ca; Mg; humic acid |
