硅对植烟土壤中镉形态、烤烟镉积累的影响

发布时间：2018-02-27 01:12

本文关键词： 镉硅烤烟镉积累镉形态　出处：《贵州大学》2015年硕士论文　论文类型：学位论文

【摘要】：本研究通过盆栽试验与土壤培养试验相结合的方式研究了硅对烤烟镉吸收积累、植烟土壤镉形态的变化规律。具体研究结果如下:1.镉污染会抑制烤烟生长。一定浓度的硅能促进镉污染下烤烟株高、茎围、最大叶叶面积、鲜重的增加。这种促进也与镉浓度有关,镉污染浓度较低时,硅对烤烟生长有一定的促进作用,镉污染浓度较高时,高硅浓度反而抑制烤烟生长。2.镉污染会使烤烟叶片中叶绿素a,叶绿素b,类胡萝卜素的含量下降,丙二醛含量,SOD活性及可溶性蛋白含量增加,与前人研究结果基本一致。一定浓度的硅能缓解镉污染对烤烟叶片的叶绿素、SOD、MDA及可溶性蛋白的胁迫影响。3.在Cd0处理中,在团棵期及旺长期,烤烟镉含量为根叶茎,而在现蕾期和成熟期烤烟镉含量为叶根茎。在Cd1处理中,在四个时期植株镉含量为叶根茎。在Cd5处理中,在旺长期烤烟镉含量表现为叶根茎,在团棵期,现蕾期及成熟期烤烟植株镉含量表现为叶茎根。4.烤烟的生长周期中镉积累速率不同,镉积累速率表现为旺长期-现蕾期团棵期-旺长期现蕾期-成熟期,在Cd0,Cd1处理中,镉积累量表现为叶根茎,而Cd5处理中镉积累量表现为叶茎根,在现蕾期、成熟期叶片镉积累基本表现为上部叶中部叶下部叶。加硅处理能够降低烤烟总镉积累量。5.在土壤--烤烟系统中镉移动指数表现为茎-叶移动指数MIs-l土-根移动指数MIs-r根-茎移动指数MIr-s,镉处理浓度越高,镉越容易向烤烟叶部转移。硅的添加使土壤--烤烟系统中镉更多的截留在了根部,抑制了镉向叶片的运输富集。6.在Cd0处理中,残渣态镉含量占全镉90%左右,弱酸提取态镉及可还原态镉所占百分比较小;在Cd1、Cd5处理中,残渣态镉含量占全镉百分比小于Cd0处理,弱酸提取态镉及可还原态镉所占百分比高于Cd0处理,且各形态镉百分含量表现为弱酸提取态镉可还原态镉残渣态镉。在Cd1、Cd5处理中,和Si0处理相比,施硅处理的弱酸提取态镉百分含量有所下降,下降程度与硅的添加量有关。7.在土壤培养试验中,Cd1处理中,硅的添加能降低土壤中有效镉的含量,硅添加浓度越高,有效镉含量越低,随着土壤培养时间的增加,Cd1处理中的有效镉呈先增加后降低的趋势。Cd5处理中,硅的添加对土壤中有效镉的含量无明显降低的效果。土壤有效磷含量表现为Cd5处理Cd1处理,不同硅添加的浓度会使培养土壤的pH值含量增高。
[Abstract]:The absorption and accumulation of cadmium by silicon in flue-cured tobacco were studied by means of pot experiment and soil culture experiment. The specific results are as follows: 1. Cadmium pollution can inhibit the growth of flue-cured tobacco. A certain concentration of silicon can promote the plant height, stem circumference and maximum leaf area of flue-cured tobacco under cadmium pollution. The increase of fresh weight is also related to the concentration of cadmium. When the concentration of cadmium pollution is low, silicon can promote the growth of flue-cured tobacco to some extent, and when the concentration of cadmium pollution is higher, the growth of flue-cured tobacco can be promoted by silicon. On the contrary, high silicon concentration inhibited the growth of flue-cured tobacco. Cadmium pollution decreased the contents of chlorophyll a, chlorophyll b, carotenoid in flue-cured tobacco leaves, and increased the content of malondialdehyde (MDA) and soluble protein. The results were consistent with those of previous studies. A certain concentration of silicon could alleviate the stress of cadmium pollution on chlorophyll SODN MDA and soluble protein in flue-cured tobacco leaves. 3. In the Cd0 treatment, the cadmium content of flue-cured tobacco was root and leaf stem in root-leaf stem at rosette stage and peak stage. The cadmium content of flue-cured tobacco at budding stage and mature stage was leaf rhizome, in Cd1 treatment, CD content was leaf rhizome in four stages, in Cd5 treatment, CD content in flue-cured tobacco appeared as leaf rhizome in flourishing stage, and in rootstock stage in rosette stage. The CD content of flue-cured tobacco plants at budding stage and mature stage was as follows: leaf stem root. 4. The CD accumulation rate was different in the growth cycle of flue-cured tobacco. The CD accumulation rate of flue-cured tobacco was from rosette stage to budding stage to bud stage to mature stage, and it was treated with CD _ (0) CD _ (1). The accumulation of cadmium in leaves and stems was observed in leaves and stems, while in Cd5 treatment, the accumulation of cadmium in leaves, stems and roots, was observed at budding stage. The accumulation of cadmium in leaves at maturity stage was basically the lower leaves of middle leaves of upper leaves, and the total cadmium accumulation of flue-cured tobacco decreased by adding silicon. In the soil-flue-cured tobacco system, the cadmium movement index was shown as stem leaf movement index (MIs-l), soil-root movement index (MIs-l). The number of MIs-r root-stem movement index MIr-s, the higher the concentration of cadmium treatment, The more easily cadmium was transferred to the tobacco leaves, the more cadmium in the soil-flue-cured tobacco system was intercepted by adding silicon, which inhibited the transport and enrichment of cadmium to the leaves. In the Cd0 treatment, the residual cadmium content accounted for about 90% of the total cadmium. The percentage of residual cadmium in Cd0 treatment was lower than that in Cd0 treatment, and the percentage of weak acid extractable cadmium and reducible cadmium was higher than that of Cd0 treatment. In addition, the percentage of cadmium in each form was reduced to that of residual cadmium in the form of weak acid extractable cadmium. Compared with the treatment of Si0, the content of cadmium in the extracted form of weak acid was decreased in the treatment of CD _ (1) O _ (1) CD _ (5). In soil culture experiment, the addition of silicon can reduce the content of available cadmium in soil, the higher the concentration of silicon, the lower the content of available cadmium. With the increase of soil culture time, the available cadmium in the treatment of CD 1 increased first and then decreased. In the treatment of CD 5, the addition of silicon had no significant effect on the content of available cadmium in the soil. The content of available phosphorus in the soil showed that the content of available phosphorus in the soil was treated with Cd1 treatment with Cd5. The pH value of cultured soil was increased by adding different concentrations of silicon.
【学位授予单位】：贵州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X53;S572

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