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[目的]研究基质块复合不同剂量轻稀土对青椒生长、Cd吸收阻控及Cd在器官中分配的影响,以期为受污染达到一定程度的耕地开发合格的根际调控产品提供理论依据。[方法]以青椒为供试蔬菜、以Cd为试验重金属,采用盆栽试验探索根际调控基质块复合不同剂量碳酸轻稀土对青椒生长、镉吸收阻控及镉在植株体内分配的影响。[结果]当稀土剂量为40mg/kg时,与对照相比,极大地促进了青椒苗株高和干重的增加,分别提高了21.52%和11.11%。在高污染等级(5.14mg/kg)的Cd胁迫下,保留基质块处理比冲掉的(裸栽)处理植株地上部生物量、植株生物量、果干重均显著增加,而对根系却没有明显的促进作用;不管基质块中添加不添加稀土,该浓度的Cd胁迫显著抑制了植株根系生长,但适当的稀土添加能够在基质块缓解Cd对青椒毒害的基础上使青椒的生理状况得到进一步改善,而对植株产果没有显著的促进作用,另外,任何剂量的稀土添加对根系Cd含量没有显著抑制作用。而当稀土剂量为10mg/kg时,显著促进了茎、叶中Cd的含量,但可显著降低果实中Cd含量。叶中Cd含量与稀土添加剂量存在回归方程y=-4E-05x2+0.0096x+0.6556,R2=0.5426,而根、茎、果Cd含量的回归方程不成立。[结论]该试验为今后系统开展复合根际重金属阻控研究奠定了基础。
[Objective] The research aimed to study the effects of light rare earths with different dosages on the growth of peppers, the control of Cd absorption and the distribution of Cd in organs. The purpose is to provide a theoretical basis for the development of qualified rhizobacteria control products which reach a certain degree of pollution. [Method] With green peppers as test vegetables and Cd as test heavy metal, pot experiments were conducted to explore the effects of rhizosphere matrix and light rare earths with different dosages on the growth of peppers, the control of cadmium absorption and the distribution of cadmium in plants. [Result] When the dosage of rare earth was 40 mg / kg, the height and dry weight of green pepper seedlings were significantly increased by 21.52% and 11.11% respectively compared with the control. Under Cd stress of high pollution level (5.14mg / kg), the aboveground biomass, plant biomass and dry weight of the treated plants were significantly increased compared with those of the bare plant treated with substrate block, However, the addition of appropriate rare earth could further alleviate the toxicity of Cd to green peppers on the basis of Cd concentration in the matrix blocks, which further led to the physiological status of green peppers Improve, but did not promote the plant fruit significantly, in addition, any dose of rare earth added to the root Cd content was not significantly inhibited. When the dosage of rare earth was 10 mg / kg, the content of Cd in stem and leaf was significantly increased, but the content of Cd in fruits was significantly decreased. The regression equations of Cd content in leaf and RE dosage were y = -4E-05x2 + 0.0096x + 0.6556, R2 = 0.5426, while the regression equations of root, stem and fruit Cd content did not hold. [Conclusion] This experiment laid the foundation for the future systematic study on heavy metal resistance in composite rhizosphere.