钝化剂对烟草吸收镉及生长发育的影响

发布时间：2018-07-20 16:02

【摘要】：本试验研究了 Cd对烟草种子萌发、幼苗生长发育的影响,采用盆栽试验研究了不同生物炭、豆饼用量对烟草中重金属Cd的钝化作用以及在整个生长发育过程中对烟株的影响。旨在为我省控制烟草中的Cd提供理论基础。主要研究结果如下:(1)Cd污染对烟草种子具有毒害作用。本试验表明,随着Cd浓度的增加,烟草种子发芽势、发芽率、发芽指数、活力指数、苗高,均受到了一定程度的抑制。当Cd浓度为10 mg/L时,幼芽毒害死亡率超过了 50%。(2)在Cd胁迫下,烟草幼苗生长受到一定程度的抑制,且随Cd浓度的不断增大,抑制程度也不断增加。叶绿素含量显著降低,幼苗生长长势越来越差,根冠比逐渐变小,抑制了烟苗的健康生长。(3)在Cd胁迫下,幼苗体内抗氧化酶系统被破坏,多种酶活性不协调,生理过程紊乱,最终导致烟苗受害。CAT活性、SOD活性、可溶性糖含量表现为先增加后降低的趋势,POD活性、MDA含量、Pro含量、Cd含量均随Cd浓度的增加而增加。(4)在Cd胁迫下,烟株生长发育受到抑制,在不同钝化剂处理下,生长在不同浓度Cd污染土壤中的烟株在株高、叶片数、最大叶长、最大叶宽、茎围、干物质积累、根冠比有不同程度的增加,能够减轻Cd胁迫对烟株的抑制作用,促进烟株的生长发育。(5)不同钝化剂能够缓解Cd胁迫对烟株体内抗氧化酶系统的破坏,不同程度的增加叶绿素含量、CAT活性,降低POD活性、MDA含量、Pro含量;当Cd≤5mg/kg时,SOD活性降低,当Cd浓度为10mg/kg时,SOD活性升高;当Cd≤2mg/kg时,可溶性糖含量降低,当Cd≥5mg/kg时,可溶性糖含量升高。(6)烟叶中的Cd含量随Cd浓度的升高而升高。在整个生长发育期间,Cd含量的变化趋势为先降低后增高。当在土壤中施以钝化剂时,能够不同程度的降低烟叶中各部位的Cd含量,说明钝化剂对烟草中的Cd具有消减作用。(7)Cd胁迫下,烟叶化学成分趋于不协调,不利于优质烟叶的形成,当在土壤中施以钝化剂时,能够降低总氮含量、蛋白质含量、总糖含量、还原糖含量,增加烟碱含量、淀粉含量,使得施木克值、糖碱比、氮碱比降低,钾氯比增加。(8)烟株中的Cd含量分布为根茎上部叶中部叶下部叶。当土壤中施以钝化剂时,各部位烟叶中的Cd含量均有不同程度的降低,减少了烟株对Cd的吸收。(9)两种钝化剂及不同比例对烟叶吸收重金属影响不尽相同,其中0.5%生物炭综合表现好于1.0%生物炭,0.5%豆饼综合表现好于1.0%豆饼。
[Abstract]:The effects of CD on the germination of tobacco seeds and the growth and development of tobacco seedlings were studied. Pot experiments were conducted to study the effects of different amounts of biochar and soybean cake on the passivation of CD in tobacco and the effects of CD on tobacco plants during the whole process of growth and development. The aim is to provide a theoretical basis for the control of CD in tobacco in our province. The main results are as follows: (1) CD pollution has toxic effect on tobacco seeds. The results showed that with the increase of CD concentration, the germination potential, germination rate, germination index, vigor index and seedling height of tobacco seeds were inhibited to some extent. When CD concentration was 10 mg / L, the death rate of shoot toxicity exceeded 50%. (2) under CD stress, the growth of tobacco seedlings was inhibited to a certain extent, and with the increasing of CD concentration, the inhibition degree also increased. Chlorophyll content decreased significantly, seedling growth became worse and worse, root to shoot ratio gradually decreased, which inhibited the healthy growth of tobacco seedlings. (3) under CD stress, the antioxidant enzyme system was destroyed, the activities of many enzymes were not coordinated, and the physiological process was disturbed. The content of soluble sugar increased firstly and then decreased. The content of MDA and Pro increased with the increase of CD concentration. (4) under CD stress, the growth and development of tobacco plants were inhibited. Under different passivant treatments, the plant height, number of leaves, maximum leaf length, maximum leaf width, stem circumference, dry matter accumulation and root-shoot ratio increased in different concentrations of CD contaminated soil. (5) different passivating agents can alleviate the damage of antioxidant enzyme system and increase the activity of cat in chlorophyll content in different degree, which can reduce the inhibition of CD stress on tobacco plants, promote the growth and development of tobacco plants, and promote the growth and development of tobacco plants. The activity of SOD decreased when CD 鈮，

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